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  smsc emc1422 datasheet revision 2.0 (08-10-12) datasheet product features emc1422 1c temperature sensor with hardware thermal shutdown general description the emc1422 is a high accuracy, low cost, system management bus (smbus) temperature sensor. advanced features such as resistance error correction (rec), beta compensation (to support cpu diodes requiring the bjt/transistor model including 45nm, 65nm and 90nm processors) and automatic diode type detection combine to provide a robust solution for complex environmental monitoring applications. additionally, the emc1422 provides a hardware programmable system shut down feature that is programmed at part power-u p via two pull-up resistor values and that cannot be masked or corrupted through the smbus. each device provides 1 accuracy for external diode temperatures and 2c accuracy for the internal diode temperature. the emc1422 monitors two temperature channels (one external and one internal). resistance error correction automatically eliminates the temperature error caused by series resistance allowing greater flexibility in routing thermal diodes. beta compensation eliminates tem perature errors caused by low, variable beta transistors common in today's fine geometry processors. the automatic beta detection feature monitors the external diode/transistor and determines the optimum sens or settings fo r accurate temperature measurements regardless of processor technology. this frees the user from providing unique sensor configurations for each temperature monitoring application. these advanc ed features plus 1c measurement accuracy prov ide a low-cost, highly flexible and accurate solution for critical temperature monitoring applications. applications ? notebook computers ? desktop computers ? industrial ? embedded applications features ? hardware thermal shutdown ? triggers dedicated sys_shdn pin ? hardware configured range 77c to 112c in 1c steps ? cannot be disabled or modified by software ? support for diodes requiring the bjt/transistor model ? supports 45nm, 65nm, and 90nm cpu thermal diodes. ? pin compatible with adm1032, max6649, and lm99 ? automatically determines external diode type and optimal settings ? resistance e rror correction ? external temperature monitors ? 1c accuracy (60c < t diode < 100c) ? 0.125c resolution ? supports up to 2.2nf diode filter capacitor ? internal temperature monitor ? 2c accuracy ? 3.3v supply voltage ? programmable temperature limits for alert ? available in small 8-pin msop lead-free rohs compliant package
ordering information: emc1422-1-aczl-tr for 8-pin, msop lead-free rohs compliant package note: see table 1.1, "part selection" for smbus addressing options. reel size is 4,000 pieces. this product meets the halogen maximum concentration values per iec61249-2-21 for rohs compliance and environmen tal information, please visit www.smsc.com/rohs please contact your smsc sales representative fo r additional documentation related to this product such as application notes, anomaly sheets, and design guidelines. 1c temperature sensor with hardware thermal shutdown datasheet revision 2.0 (08-10-12) 2 smsc emc1422 datasheet copyright ? 2012 smsc or its subsidiaries. all rights reserved. circuit diagrams and other information relating to smsc produc ts are included as a means of illustrating typical applications. consequently, complete information sufficient for construction purposes is not necessarily given. although the information has been checked and is believed to be accurate, no re sponsibility is assumed for inaccuracies. smsc reserves the right to make changes to specifications and produc t descriptions at any time without notice. contact your local sm sc sales office to obtain the latest specifications before placing your product order. the provision of this inform ation does not convey to the purchaser of the described semicond uctor devices any licenses under any patent rights or other intellectual property rights of smsc or others. all sales are expressly conditional on your agreement to the te rms and conditions of the most recently dated version of smsc's standard terms of sale agreement dated before the date of your order (the "terms of sale agreement"). the pro duct may contain design defects or errors known as anomalies which may cause the product's functions to deviate from published specifications. anomaly sheets are availab le upon request. smsc products are not designed, intended, authorized or warranted for use in any life support or other application where product failure could cause or contribute to personal injury or severe property damage. any and all such uses without prior written approval of an officer of smsc and further testing and/or modification will be fully at the risk of the customer. copies of this document or other smsc literature, as well as the terms of sale agreement, may be obtained by visiting smsc?s website at h ttp://www.smsc.com. smsc is a registered trademark of standard microsystems corporat ion (?smsc?). product names and company na mes are the trademarks of their respective holders. smsc disclaims and excludes any and all warrant ies, including without limi tation any and all implied warranties of merchantabil ity, fitness for a particular purpose, title, a nd against infringement and the like, and any and all warranties arising from any cou rse of dealing or usage of trade. in no event shall smsc be liable for any direct, incidental, indi rect, special, punitive, or cons equential damages; or for lost data, profits, savings or revenues of any kind; regardless of the form of action, whether based on contrac t; tort; negligence of smsc or others; strict liability; breach of wa rranty; or otherwise; whether or not any remedy of buyer is h eld to have failed of its essential purpose, and whether or not smsc has been advised of the possibility of such damages.
1c temperature sensor with hardware thermal shutdown datasheet smsc emc1422 3 revision 2.0 (08-10-12) datasheet table of contents chapter 1 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.1 part selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 chapter 2 pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 chapter 3 electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.1 absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.2 electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.3 smbus electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 chapter 4 system management bus interface protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 4.1 system management bus interface protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 4.2 write byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 4.3 read byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 4.4 send byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 4.5 receive byte. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 4.6 alert response address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 4.7 smbus address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 4.8 smbus timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 chapter 5 product description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 5.0.1 conversion rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 5.0.2 dynamic averaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 5.1 sys_shdn output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 5.2 hardware thermal shutdown limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 5.3 alert output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 5.3.1 alert pin interrupt mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 5.3.2 alert pin comparator mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 5.4 alert and sys_shdn pin considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 5.5 beta compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 5.6 resistance error correction (rec) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 5.7 diode faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 5.8 consecutive alerts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 5.9 digital filter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 5.10 temperature monitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 5.11 temperature measurement results and data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 5.12 external diode connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 chapter 6 register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 6.1 data read interlock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 6.2 temperature data registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 6.3 status register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 6.4 configuration register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 6.5 conversion rate register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 6.6 limit registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 6.7 scratchpad registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 6.8 therm limit registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 6.9 external diode fault register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 6.10 software thermal shutdown configuration register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 6.11 hardware thermal shutdown limit regist er . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
1c temperature sensor with hardware thermal shutdown datasheet revision 2.0 (08-10-12) 4 smsc emc1422 datasheet 6.12 channel mask register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 6.13 consecutive alert register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 6.14 high limit status register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 6.15 low limit status register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 6.16 therm limit status register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 6.17 filter control register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 6.18 product id register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 6.19 smsc id register (feh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 6.20 revision register (ffh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 chapter 7 typical operating curves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 chapter 8 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 8.1 package markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 chapter 9 datasheet revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
1c temperature sensor with hardware thermal shutdown datasheet smsc emc1422 5 revision 2.0 (08-10-12) datasheet list of figures figure 1.1 emc1422 block diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 figure 2.1 emc1422 pin diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 figure 4.1 smbus timing diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 figure 5.1 system diagram for emc1422 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 figure 5.2 block diagram of ha rdware thermal shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 figure 5.3 isolating alert and sys_shdn pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 figure 5.4 temperature filter step response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 figure 5.5 temperature filter impulse response. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 figure 5.6 block diagram of temperature monitoring circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 figure 5.7 diode configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 figure 8.1 8-pin msop / tssop package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
1c temperature sensor with hardware thermal shutdown datasheet revision 2.0 (08-10-12) 6 smsc emc1422 datasheet list of tables table 1.1 part selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 table 2.1 emc1422 pin description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 table 3.1 absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 table 3.2 electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 table 3.3 smbus electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 table 4.1 protocol format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 table 4.2 write byte protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 table 4.3 read byte protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 table 4.4 send byte protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 table 4.5 receive byte protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 table 4.6 alert response address protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 table 5.1 supply current vs. conversion rate for emc1422 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 table 5.2 sys_shdn threshold temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 table 5.3 temperature data format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 table 6.1 register set in hexadecimal order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 table 6.2 temperature data registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 table 6.3 status register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 table 6.4 configuration register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 table 6.5 conversion rate register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 table 6.6 conversion rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 table 6.7 temperature limit registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 table 6.8 scratchpad register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 table 6.9 therm limit registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 table 6.10 external diode fault register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 table 6.11 software thermal shutdown configuration register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 table 6.12 hardware thermal shutdown limit register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1 table 6.13 channel mask register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 table 6.14 consecutive alert register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 table 6.15 consecutive alert / therm settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 table 6.16 high limit status register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 table 6.17 low limit status register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 table 6.18 therm limit status register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 table 6.19 filter configuration register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 table 6.20 filter settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 table 6.21 product id register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 table 6.22 manufacturer id register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 table 6.23 revision register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 table 9.1 customer revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
1c temperature sensor with hardware thermal shutdown datasheet smsc emc1422 7 revision 2.0 (08-10-12) datasheet chapter 1 block diagram figure 1.1 emc1422 block diagram 1.1 part selection the emc1422 device configuration is highlighted below. table 1.1 part selection part number smbus address functionality product id external diodes diode 1 default configuration diode 2 default configuration other emc1422 - 1 1001_100xb 1 detect diode w/ rec enabled n/a software program- mable and mask- able high limit software program- mable and mask- able sys_shdn limit hardware set sys_shdn limit on external diode 1 22h internal temp diode switching current analog mux internal temperature register digital mux digital mux limit comparator low limit registers high limit registers conversion rate register interupt masking status registers configuration register smbus interface alert sys_shdn smclk smdata dp1 dn1 v dd gnd emc1422 external temperature register(s) ? adc sys_shdn limit
1c temperature sensor with hardware thermal shutdown datasheet revision 2.0 (08-10-12) 8 smsc emc1422 datasheet chapter 2 pin description figure 2.1 emc1422 pin diagram application note: for the 5v tolerant pins that have a pull-up resist or (smclk, smdata, sys_shdn , and alert ), the voltage difference between vdd and the pull-up voltage must never exceed 3.6v. the pin types are described below: power - these pins are used to supply either vdd or gnd to the device. aio - analog input / output. di - digital input. od - open drain digital output. diod - digital input / open drain output. table 2.1 emc1422 pin description pin number name function type 1 vdd power supply power 2 dp external diode positive (anode) connection aio 3 dn external diode negative (cathode) connection aio 4 sys_shdn active low system shutdown output signal - requires pull-up resistor which selects the hardware thermal shutdown limit od (5v) 5 gnd ground power 6 alert active low digital alert output signal - requires pull-up resistor od (5v) 7 smdata smbus data input/output - requires pull-up resistor diod (5v) 8 smclk smbus clock input - requires pull- up resistor di (5v) smdata smclk alert vdd dp1 dn1 sys_shdn gnd 1 2 3 4 5 8 7 6
1c temperature sensor with hardware thermal shutdown datasheet smsc emc1422 9 revision 2.0 (08-10-12) datasheet chapter 3 electrical specifications 3.1 absolute maximum ratings note: stresses at or above those listed could cause pe rmanent damage to the device. this is a stress rating only and functional operation of the devic e at any other condition above those indicated in the operation sections of this specification is not implied. when powering this device from laboratory or system power supplie s, it is important that the absolute maximum ratings not be exceeded or device failure can result. some po wer supplies exhibit voltage spikes on their outputs when the ac power is switched on or of f. in addition, voltage transients on the ac power line may appear on the dc output. if this po ssibility exists, it is suggested that a clamp circuit be used. note 3.1 for the 5v tolerant pins that have a pull-up resistor (smclk, smdata, sys_shdn , and alert ), the pull-up voltage must not exceed 3.6v when the device is unpowered. table 3.1 absolute maximum ratings description rating unit supply voltage (v dd ) -0.3 to 4.0 v voltage on 5v tolerant pins (v 5vt_pin ) -0.3 to 5.5 v voltage on 5v tolerant pins (|v 5vt_pin - v dd |) (see note 3.1 ) -0.3 to 3.6 v voltage on any other pin to ground -0.3 to v dd +0.3 v operating temperature range -40 to +125 c storage temperature range -55 to +150 c lead temperature range refer to jedec spec. j-std-020 package thermal charac teristics for msop-8 thermal resistance ( j-a ) 140.8 c/w esd rating, all pins hbm 2000 v
1c temperature sensor with hardware thermal shutdown datasheet revision 2.0 (08-10-12) 10 smsc emc1422 datasheet 3.2 electrical specifications note 3.2 during the power up time, smbus communic ation is permitted, however the sys_shdn and alert pins must not be pulled low. table 3.2 electri cal specifications v dd = 3.0v to 3.6v, t a = -40c to 125c, all typical values at t a = 27c unless otherwise noted. characteristic symbol min typ max units conditions dc power supply voltage v dd 3.0 3.3 3.6 v supply current i dd 430 850 ua 1 conversion / sec, dynamic averaging disabled 930 1200 ua 4 conversions / sec, dynamic averaging enabled 1120 ua > 16 conversions / sec, dynamic averaging enabled internal temperature monitor temperature accuracy 0.25 1 c -5c < t a < 100c 2 c -40c < t a < 125c temperature resolution 0.125 c external temperature monitor temperature accuracy 0.25 1 c +20c < t diode < +110c 0c < t a < 100c 0.5 2 c -40c < t diode < 127c temperature resolution 0.125 c conversion time all channels t conv 190 ms emc1422, default settings capacitive filter c filter 2.2 2.5 nf connected across external diode alert and sys_shdn pins output low voltage v ol 0.4 v i sink = 8ma leakage current i leak 5 ua alert and sys_shdn pins device powered or unpowered t a < 85c pull-up voltage < 3.6v power up time 15 ms temp selection read note 3.2
1c temperature sensor with hardware thermal shutdown datasheet smsc emc1422 11 revision 2.0 (08-10-12) datasheet 3.3 smbus electrica l characteristics table 3.3 smbus elec trical specifications v dd = 3.0v to 3.6v, t a = -40c to 125c, all typical values are at t a = 27c unless otherwise noted. characteristic symbol min typ max units conditions smbus interface input high voltage v ih 2.0 v dd v 5v tolerant input low voltage v il -0.3 0.8 v 5v tolerant input high/low current i ih / i il 5 ua powered or unpowered ta < 85c hysteresis 420 mv input capacitance c in 5pf output low sink current i ol 8.2 15 ma smdata = 0.4v smbus timing clock frequency f smb 10 400 khz spike suppression t sp 50 ns bus free time start to stop t buf 1.3 us hold time: start t hd:sta 0.6 us setup time: start t su:sta 0.6 us setup time: stop t su:stp 0.6 us data hold time t hd:dat 0 us when transmitting to the master data hold time t hd:dat 0.3 us when receiving from the master data setup time t su:dat 100 ns clock low period t low 1.3 us clock high period t high 0.6 us clock/data fall time t fall 300 ns min = 20+0.1c load ns clock/data rise time t rise 300 ns min = 20+0.1c load ns capacitive load c load 400 pf per bus line
1c temperature sensor with hardware thermal shutdown datasheet revision 2.0 (08-10-12) 12 smsc emc1422 datasheet chapter 4 system management bus interface protocol 4.1 system management bus interface protocol the emc1422 communicates with a host controller, su ch as an smsc sio, through the smbus. the smbus is a two-wire serial communication prot ocol between a computer host and its peripheral devices. a detailed timing diagram is shown in figure 4.1 . for the first 15ms after power-up the device may not respond to smbus communications. . the emc1422 is smbus 2.0 compatible and support send byte, read byte, write byte, receive byte, and the alert response address as valid protocols as shown below. all of the below protocols use the convention in ta b l e 4.1 . attempting to communicate with t he emc1422 smbus interface with an invalid slave address or invalid protocol will result in no response from the devic e and will not affect its register contents. stretching of the smclk signal is support ed, provided other devices on the smbus control the timing. 4.2 write byte the write byte is used to write one byte of data to the registers as shown below table 4.2 : figure 4.1 smbus timing diagram table 4.1 protocol format data sent to device data sent to the host # of bits sent # of bits sent table 4.2 write byte protocol start slave address wr ack register address ack register data ack stop 1 -> 0 1001_100 0 0 xxh 0 xxh 0 0 -> 1 smdta smclk t low t rise t high t fall t buf t hd:sta p s s - start condition p - stop condition t hd:dat t su:dat t su:sta t hd:sta p t su:sto s
1c temperature sensor with hardware thermal shutdown datasheet smsc emc1422 13 revision 2.0 (08-10-12) datasheet 4.3 read byte the read byte protocol is used to read one byte of data from the registers as shown in table 4.3 . 4.4 send byte the send byte protocol is used to set the internal address register pointer to the correct address location. no data is transferred during the send byte protocol as shown in ta b l e 4.4 . 4.5 receive byte the receive byte protocol is used to read data from a register when the internal register address pointer is known to be at the right location (e.g. se t via send byte). this is used for consecutive reads of the same register as shown in ta b l e 4.5 . 4.6 alert response address the alert output can be used as a proce ssor interrupt or as an smbus alert. when it detects that the alert pin is asserted, the host will send the alert response address (ara) to the general address of 0001_100xb. all devices with active interrupts will respond with their client address as shown in table 4.6 . table 4.3 read byte protocol start slave address wr ack register address ack start slave address rd ack register data nack stop 1 -> 0 1001_100 0 1 xxh 0 1 -> 0 1001_100 1 1 xx 1 0 -> 1 table 4.4 send byte protocol start slave address wr ack register address ack stop 1 -> 0 1001_100 0 0 xxh 0 0 -> 1 table 4.5 receive byte protocol start slave address rd ack register data nack stop 1 -> 0 1001_100 1 0 xxh 1 0 -> 1 table 4.6 alert response address protocol start alert response address rd ack device address nack stop 1 -> 0 0001_100 1 0 1001_1000 1 0 -> 1
1c temperature sensor with hardware thermal shutdown datasheet revision 2.0 (08-10-12) 14 smsc emc1422 datasheet the emc1422 will respond to the ara in the following way: 1. send slave address and verify that full slav e address was sent (i.e. the smbus communication from the device was not prematurely stopped due to a bus contention event). 2. set the mask bit to clear the alert pin. application note: the ara does not clear the status register and if the mask bit is cleared prior to the status register being cleared, the alert pin will be reasserted. 4.7 smbus address the emc1422 responds to hard-wired smbus slave address as shown in table 1.1 . note: other addresses are available. contact smsc for more information. 4.8 smbus timeout the emc1422 supports smbus timeout. if the clock lin e is held low for longer than 30ms, the device will reset its smbus protocol. this function can be enabled by setting the timeout bit in the consecutive alert register (see section 6.13 ).
1c temperature sensor with hardware thermal shutdown datasheet smsc emc1422 15 revision 2.0 (08-10-12) datasheet chapter 5 product description the emc1422 is an smbus temperature sensor with hardware thermal shutdown. the emc1422 monitors one internal diode and one ex ternally connected temperature diode. thermal management is performed in cooperation with a host device. this consists of the host reading the temperature data of both the external and inte rnal temperature diodes of the emc1422 and using that data to control the speed of one or more fans. the emc1422 has two levels of monitoring. the first provides a maskable alert signal to the host when measured temperatur es meet or exceed user programmable limits. this allows the emc1422 to be used as an independent thermal watchdog to warn the host of temperature hot spots without direct control by the host. the second level of monitoring asserts the sys_shdn pin when the external diode temperature exceeds a hardware specified threshold temperature. additionally, the internal diodecan be configured to assert the sys_shdn pin when the measured temperature exceeds user programmable limits. since the emc1422 automatically corrects for te mperature errors due to series resistance in temperature diode lines, there is gr eater flexibility in where external diodes are positioned and better measurement accuracy than previously available with non-resistance error correcting devices. the automatic beta detection feature means that there is no need to program the device according to which type of diode is present. this also includes cpu di odes that require the tran sistor or bjt model for monitoring their temperature. ther efore, the emc1422 can power up re ady to operate for any system configuration. figure 5.1 shows a system level block diagram of the emc1422. 5.0.1 conversion rates the emc1422 may be configured for different c onversion rates based on the system requirements. the conversion rate is configured as described in section 6.5 . the default conversion rate is 4 conversions per second. other availa ble conversion rates are shown in ta b l e 6.6 . 5.0.2 dynamic averaging dynamic averaging causes the emc1422 to measure the external diode channels for an extended time based on the selected conversion rate. this functionality can be disabled for increased power savings at the lower conversion rates (see section 6.4 ). when dynamic averaging is enabled, the device will automatically adjust the sampling and measurement time for the external diode channels. this allows the device to average 2x or 16x longer than the no rmal 11 bit operation (nominally 21ms per channel) figure 5.1 system diagram for emc1422 cpu emc1422 host dp1 dn1 smdata thermal diode internal diode smclk smbus interface sys_shdn alert power control
1c temperature sensor with hardware thermal shutdown datasheet revision 2.0 (08-10-12) 16 smsc emc1422 datasheet while still maintaining the selected conversion ra te. the benefits of dynamic averaging are improved noise rejection due to the longer integration time as well as less random variation of the temperature measurement. when enabled, the dynamic averaging will affect the average supply current based on the chosen conversion rate as shown in ta b l e 5.1 for the emc1422 . 5.1 sys_shdn output the sys_shdn output is asserted independently of the alert output and cannot be masked. if the external diode temperature exce eds the hardware thermal shutdown limit for the programmed number of consecutive measurements, then the sys_shdn pin is asserted. the hardware thermal shutdown limit is defined at power-up via the pull-up resistors on the sys_shdn and alert pins as shown in ta b l e 5.2 . this limit cannot be modified or masked via software. in addition to external diode channel triggering the sys_shdn pin when the measured temperature exceeds to the hardware thermal shutdown limit, each of the measurement channels can be configured to assert the sys_shdn pin when they exceed the corresponding therm limit. when the sys_shdn pin is asserted, it will not release unt il the external diode temperature drops below the hardware thermal shutdown limit minus 10c and all other measured temperatures drop below the therm limit minus the ther m hysteresis value (when linked to sys_shdn ). figure 5.2 shows a block diagram of the interaction between the input channels and the sys_shdn pin. table 5.1 supply current vs. conversion rate for emc1422 conversion rate average supply current averaging factor (based on 11-bit operation) enabled (default) disabled enabled (default) disabled 1 / sec 660ua 430ua 16x 1x 2 / sec 930ua 475ua 16x 1x 4 / sec (default) 950ua 510ua 8x 1x 8 / sec 1010ua 630ua 4x 1x 16 / sec 1020ua 775ua 2x 1x 32 / sec 1050ua 1050ua 1x 1x 64 / sec 1100ua 1100ua 0.5x 0.5x
temperature conversion function select hw_shdn h/w thermal shutdown sensor hardware thermal shutdown smbus traffic sw_shdn 3.3v alert sys_shdn software shutdown enable 3.3v temperature conversion and therm limit compare internal diode 1c temperature sensor with hardware thermal shutdown datasheet smsc emc1422 17 revision 2.0 (08-10-12)  datasheet 5.2 hardware thermal shutdown limit the hardware thermal shutdown limit temperat ure is determined by pull-up resistors on the sys_shdn and alert pins shown in ta b l e 5.2 . 5.3 alert output the alert pin is an open drain output and requires a pull-up resistor to v dd and has two modes of operation: interrupt mode and comparator mode. the mode of the alert output is selected via the alert / comp bit in the configuration register (see section 6.4 ). figure 5.2 block diagram of hardware thermal shutdown table 5.2 sys_shdn threshold temperature 4.7k ohm 10% 6.8k ohm 10% 10k ohm 10% 15k ohm 10% 22k ohm 10% 33k ohm 10% 4.7k ohm 10% 77c 83c 89c 95c 101c 107c 6.8k ohm 10% 78c 84c 90c 96c 102c 108c 10k ohm 10% 79c 85c 91c 97c 103c 109c 15k ohm 10% 80c 86c 92c 98c 104c 110c 22k ohm 10% 81c 87c 93c 99c 105c 111c 33k ohm 10% 82c 88c 94c 100c 106c 112c sys_shd pull-up pull-up alert
1c temperature sensor with hardware thermal shutdown datasheet revision 2.0 (08-10-12) 18 smsc emc1422 datasheet 5.3.1 alert pin interrupt mode when configured to operate in interrupt mode, the alert pin asserts low when an out of limit measurement ( > high limit or < low limit) is detected on any diode or when a di ode fault is detected. the alert pin will remain asserted as long as an out-of -limit condition remains. once the ou t-of-limit condition has been removed, the alert pin will remain asserted until the appropriate status bits are cleared. the alert pin can be masked by sett ing the mask bit. once the alert pin has been masked, it will be de-asserted and remain de -asserted until the mask bit is cleared by the user. any interrupt conditions that occur while the alert pin is masked will update the status register normally. the alert pin is used as an interrupt signal or as an smbus alert signal that allows an smbus slave to communicate an error condition to the master. one or more alert outputs can be hard-wired together. 5.3.2 alert pin comparator mode when the alert pin is configured to operate in comp arator mode it will be asserted if any of the measured temperatures exceeds the respective high limit. the alert pin will remain asserted until all temperatures drop below the corresponding high limit minus the therm hysteresis value. when the alert pin is asserted in comparator mode, the corresponding high limit status bits will be set. reading these bits will not clear them until the alert pin is deasserted. once the alert pin is deasserted, the status bits will be automatically cleared. the mask bit will not block the alert pin in this mode, however the individual channel masks (see section 6.12 ) will prevent the respective channel from asserting the alert pin. 5.4 alert and sys_shdn pin considerations because of the decode method used to determine the hardware thermal shutdown limit, it is important that the pull- up resistance on both the alert and sys_shdn pins be within the tolerances shown in table 5.2 . additionally, the pull-up resistor on the alert and sys_shdn pins must be connected to the same 3.3v supp ly that drives the vdd pin. for 15ms after power up, the alert and sys_shdn pins must not be pulled low or the hardware thermal shutdown limit will not be dec oded properly. if the system requirements do not permit these conditions, then the alert and sys_shdn pins must be isolated from their respective busses during this time. one method of isolating this pin is shown in figure 5.3 . figure 5.3 isolating alert and sys_shdn pins smdata smclk alert vdd dp1 dn1 sys_shdn gnd 1 2 3 4 10 9 8 7 +3.3v shared alert/ 22k 4.7k - 33k +2.5 - 5v
1c temperature sensor with hardware thermal shutdown datasheet smsc emc1422 19 revision 2.0 (08-10-12) datasheet 5.5 beta compensation the emc1422 is configured to monitor the temperatur e of basic diodes (e.g. 2n3904), or cpu thermal diodes. it automatically detects the type of exter nal diode (cpu diode or diode connected transistor) and determines the optimal setting to reduce temperature errors introduced by beta variation.compensating for this error is also know n as implementing the transistor or bjt model for temperature measurement. for discrete transistors configured with the collector and base shorted together, the beta is generally sufficiently high such that the percent change in bet a variation is very small. for example, a 10% variation in beta for two forced emitter currents with a transistor whose ideal beta is 50 would contribute approximately 0.25c error at 100c. however for s ubstrate transistors where the base-emitter junction is used for temperature measurement and the collector is tied to the substrat e, the proportional beta variation will cause large error. for example, a 10% variation in beta for two forced emitter currents with a transistor whose ideal beta is 0.5 would contribute approximately 8.25c error at 100c. 5.6 resistance e rror correction (rec) parasitic resistance in series with the external diodes will limit the accuracy obtainable from temperature measurement devices. the voltage devel oped across this resistance by the switching diode currents cause the temperat ure measurement to read highe r than the true temperature. contributors to series resistance are pcb trace resistance, on die (i.e. on the processor) metal resistance, bulk resistance in the base and emitter of the temperature transistor. typically, the error caused by series resistance is +0.7c per ohm. the emc1422 automatically corrects up to 100 ohms of series resistance. application note: when monitoring a substrate transistor or cp u diode and beta compensation is enabled, the ideality factor should not be adjusted. beta compensation automatically corrects for most ideality errors. 5.7 diode faults the emc1422 detects an open on the dp and dn pi ns, and a short across the dp and dn pins. for each temperature measurement m ade, the device checks for a di ode fault on the external diode channel(s). when a diode fault is detected, the alert pin asserts (unless masked, see section 5.8 ) and the temperature data reads 00h in the msb a nd lsb registers (note: the low limit will not be checked). a diode fault is defined as one of the fo llowing: an open between dp and dn, a short from v dd to dp, or a short from v dd to dn. if a short occurs across dp and dn or a short occurs from dp to gnd, the low limit status bit is set and the alert pin asserts (unless masked). this c ondition is indistinguishable from a temperature measurement of 0.000degc (-64c in extended range) re sulting in temperature data of 00h in the msb and lsb registers. if a short from dn to gnd occurs (with a diode connected), temperature m easurements will continue as normal with no alerts. 5.8 consecutive alerts the emc1422 contains multiple consecutive alert counters. one set of counters applies to the alert pin and the second set of counters applies to the sys_shdn pin. each temperature measurement channel has a separate consecutive alert counter for each of the alert and sys_shdn pins. all counters are user programmable and determine th e number of consecutiv e measurements that a temperature channel(s) must be out-of-limit or re porting a diode fault before the corresponding pin is asserted. see section 6.13 for more details on the consecutive alert function.
1c temperature sensor with hardware thermal shutdown datasheet revision 2.0 (08-10-12) 20 smsc emc1422 datasheet 5.9 digital filter to reduce the effect of noise and temperature spik es on the reported temperat ure, the external diode channel uses a programmable digital filter. this filter can be config ured as level 1, level 2, or disabled. the typical filter performance is shown in figure 5.4 and figure 5.5 . figure 5.4 temperature filter step response filter step response 0 10 20 30 40 50 60 70 80 90 0 2 4 6 8 101214 sample s temperature (c) disabled level1 level2
1c temperature sensor with hardware thermal shutdown datasheet smsc emc1422 21 revision 2.0 (08-10-12) datasheet 5.10 temperature monitors in general, thermal diode temperat ure measurements are based on the change in forward bias voltage of a diode when operated at two different currents. this v be is proportional to absolute temperature as shown in the following equation: figure 5.6 shows a block diagram of t he temperature measurement circuit. the negative terminal for the remote temperature diode, dn, is internally biased with a forward diode voltage referenced to ground. figure 5.5 temperature filter impulse response where: k = boltzmann?s constant t = absolute temperature in kelvin [1] q = electron charge = diode ideality factor filter impulse response 0 10 20 30 40 50 60 70 80 90 02468101214 samples temperature (c) disabled level1 level2 ? ? ? ? ? ? ? ? = low high be i i q kt v ln
1c temperature sensor with hardware thermal shutdown datasheet revision 2.0 (08-10-12) 22 smsc emc1422 datasheet 5.11 temperature meas urement results and data the temperature measurement results are stored in the internal and external temperature registers. these are then compared with the values stored in the high and low limit registers. both external and internal temperature measurements ar e stored in 11-bit format with the eight (8) most significant bits stored in a high byte register and the three (3) l east significant bits stored in the three (3) msb positions of the low byte regist er. all other bits of the low byte register are set to zero. the emc1422 has two selectable temperature ranges. the default range is from 0c to +127c and the temperature is represented as binary number able to report a temperature from 0c to +127.875c in 0.125c steps. the extended range is an extended temperature ra nge from -64c to +191c. the data format is a binary number offset by 64c. the extended range is used to measure temperature diodes with a large known offset (such as amd processor diodes) wher e the diode temperature plus the offset would be equivalent to a temperature higher than +127c. table 5.3 shows the default and extended range formats. figure 5.6 block diagram of te mperature monitoring circuit table 5.3 temperature data format temperature (c) default range 0c to 127c extende d range -64c to 191c diode fault 000 0000 0000 000 0000 0000 -64 000 0000 0000 000 0000 0000 note 5.2 -1 000 0000 0000 001 1111 1000 0 000 0000 0000 note 5.1 010 0000 0000 0.125 000 0000 0001 010 0000 0001 1 000 0000 1000 010 0000 1000 dp dn anti- aliasing filter ? adc resistance error correction substrate pnp i low i high
1c temperature sensor with hardware thermal shutdown datasheet smsc emc1422 23 revision 2.0 (08-10-12) datasheet note 5.1 in default mode, all temperatures < 0c will be reported as 0c. note 5.2 in the extended range, all temperatur es < -64c will be reported as -64c. note 5.3 for the default range, all temperatures > + 127.875c will be reported as +127.875c. note 5.4 for the extended range, all temperatures > +191.875c wil l be reported as +191.875c. 5.12 external diode connections the emc1422 is hard-wired to measure a specific ki nd of thermal diode and n one of the measurement options can be changed by software. figure 5.7 shows the different diode configurations. 64 010 0000 0000 100 0000 0000 65 010 0000 1000 100 0000 1000 127 011 1111 1000 101 1111 1000 127.875 011 1111 1111 101 1111 1111 128 011 1111 1111 note 5.3 110 0000 0000 190 011 1111 1111 111 1111 0000 191 011 1111 1111 111 1111 1000 >= 191.875 011 1111 1111 111 1111 1111 note 5.4 figure 5.7 diode configurations table 5.3 temperature data format (continued) temperature (c) default range 0c to 127c extende d range -64c to 191c local ground to dp typical remote substrate transistor i.e. cpu substrate pnp typical remote discrete pnp transistor i.e. 2n3906 typical remote discrete npn transistor i.e. 2n3904 to dn to dp to dn to dp to dn
1c temperature sensor with hardware thermal shutdown datasheet revision 2.0 (08-10-12) 24 smsc emc1422 datasheet chapter 6 register description the registers shown in ta b l e 6.1 are accessible through the smbus. an entry of ?-? indicates that the bit is not used and will always read ?0?. table 6.1 register set in hexadecimal order register address r/w register name function default value page 00h r internal diode data high byte stores the integer data for the internal diode 00h page 26 01h r external diode data high byte stores the integer data for the external diode 00h 02h r status stores the status bits for the internal diode and external diodes 00h page 26 03h r/w configuration controls the general operation of the device (mirrored at address 09h) 00h page 27 04h r/w conversion rate controls the conversion rate for updating temperature data (mirrored at address 0ah) 06h (4/sec) page 28 05h r/w internal diode high limit stores the 8-bit high limit for the internal diode (mirrored at address 0bh) 55h (85c) page 29 06h r/w internal diode low limit stores the 8-bit low limit for the internal diode (mirrored at address 0ch) 00h (0c) 07h r/w external diode high limit high byte stores the integer portion of the high limit for the external diode (mirrored at register 0dh) 55h (85c) 08h r/w external diode low limit high byte stores the integer portion of the low limit for the external diode (mirrored at register 0eh) 00h (0c) 09h r/w configuration controls the general operation of the device (mirrored at address 03h) 00h page 27 0ah r/w conversion rate controls the conversion rate for updating temperature data (mirrored at address 04h) 06h (4/sec) page 28
1c temperature sensor with hardware thermal shutdown datasheet smsc emc1422 25 revision 2.0 (08-10-12) datasheet 0bh r/w internal diode high limit stores the 8-bit high limit for the internal diode (mirrored at address 05h) 55h (85c) page 29 0ch r/w internal diode low limit stores the 8-bit low limit for the internal diode (mirrored at address 06h) 00h (0c) 0dh r/w external diode high limit high byte stores the integer portion of the high limit for the external diode (mirrored at register 07h) 55h (85c) 0eh r/w external diode low limit high byte stores the integer portion of the low limit for the external diode (mirrored at register 08h) 00h (0c) 10h r external diode data low byte stores the fractional data for the external diode 00h page 26 11h r/w scratchpad scratchpad register for software compatibility 00h page 29 12h r/w scratchpad scratchpad register for software compatibility 00h page 29 13h r/w external diode high limit low byte stores the fractional portion of the high limit for the external diode 00h page 29 14h r/w external diode low limit low byte stores the fractional portion of the low limit for the external diode 00h 19h r/w external diode therm limit stores the 8-bit critical temperature limit for the external diode 55h (85c) page 30 1dh r/w sys_shdn configuration controls which software channels, if any, are linked to the sys_shdn pin 00h page 30 1eh r hardware thermal shutdown limit when read, returns the selected hardware thermal shutdown limit n/a page 31 1fh r/w channel mask register controls the masking of individual channels 00h page 31 20h r/w internal diode therm limit stores the 8-bit critical temperature limit for the internal diode 55h (85c) page 30 21h r/w therm hysteresis stores the 8-bit hysteresis value that applies to all therm limits 0ah (10c) 22h r/w consecutive alert controls the number of out-of-limit conditions that must occur before an interrupt is asserted 70h page 32 29h r internal diode data low byte stores the fractional data for the internal diode 00h page 26 35h r-c high limit status status bits for the high limits 00h page 33 36h r-c low limit status status bits for the low limits 00h page 34 table 6.1 register set in hexadecimal order (continued) register address r/w register name function default value page
1c temperature sensor with hardware thermal shutdown datasheet revision 2.0 (08-10-12) 26 smsc emc1422 datasheet 6.1 data read interlock when any temperature channel high byte register is read, the corresponding low byte is copied into an internal ?shadow? register. the user is free to r ead the low byte at any time and be guaranteed that it will correspond to the previously read high byte. regardless if the low byte is read or not, reading from the same high byte register again will auto matically refresh this stored low byte data. 6.2 temperature data registers as shown in ta b l e 6.2 , all temperatures are stored as an 11-bit value with the high byte representing the integer value and the low byte representing the fr actional value left justified to occupy the msbits. 6.3 status register 37h r therm limit status status bits for the therm limits 00h page 34 40h r/w filter control controls the digital filter setting for the external diode channel 00h page 34 fdh r product id stores a fixed value that identifies each product table 6.21 page 35 feh r smsc id stores a fixed value that represents smsc 5dh page 35 ffh r revision stores a fixed value that represents the revision number 01h or 04h page 36 table 6.2 temperature data registers addr r/w register b7 b6 b5 b4 b3 b2 b1 b0 default 00h r internal diode high byte 128 64 32 16 8 4 2 1 00h 29h r internal diode low byte 0.5 0.25 0.125 - - - - - 00h 01h r external diode high byte 128 64 32 16 8 4 2 1 00h 10h r external diode low byte 0.5 0.25 0.125 - - - - - 00h table 6.3 status register addr r/w register b7 b6 b5 b4 b3 b2 b1 b0 default 02h r status busy - - high low fault therm hwsd 00h table 6.1 register set in hexadecimal order (continued) register address r/w register name function default value page
1c temperature sensor with hardware thermal shutdown datasheet smsc emc1422 27 revision 2.0 (08-10-12) datasheet the status register reports general error condit ions. to identify specific channels, refer to section 6.9 , section 6.14 , section 6.15 , and section 6.16 . the individual status register bits are cleared when the appropriate high limit, low limit, or therm limit register has been read or cleared. bit 7 - busy - this bit indicates that the adc is currently converting. this bit does not cause the alert pin to be asserted. bit 4 - high - this bit is set when any of the temp erature channels exceeds its programmed high limit. see the high limit status register for specific channel information ( section 6.14 ). when set, this bit will assert the alert pin. bit 3 - low - this bit is set when any of the temperature channels drops below its programmed low limit. see the low limit status register for specific channel information ( section 6.15 ). when set, this bit will assert the alert pin. bit 2 - fault - this bit is asserted when a diode fault is detected on any of the external diode channels. see the external diode fault regi ster for specific channel information ( section 6.9 ). when set, this bit will assert the alert pin. bit 1 - therm - this bit is set when the any of the temperature channels exceeds its programmed therm limit. see the therm li mit status register for s pecific channel information ( section 6.16 ). bit 0 - hwsd - this bit is set when the external diode temperature exceeds the hardware thermal shutdown limit set by the pull-up resistors on the alert and sys_shdn pins. when set, this bit will assert the sys_shdn pin. 6.4 configuration register the configuration register controls the basic operati on of the device. this register is fully accessible at either address. bit 7 - mask_all - masks the alert pin from asserting. ? ?0? (default) - the alert pin is not masked. if any of the appropriate status bits are set the alert pin will be asserted. ? ?1? - the alert pin is masked. it will not be asserted for any interrupt condition unless it is configured to act in comparator mode. th e status registers will be updated normally. bit 5 - alert/comp - controls the operation of the alert pin. ? ?0? (default) - the alert pin acts as described in section 5.3 . ? ?1? - the alert pin acts in comparator mode as described in section 5.3.2 . in this mode the mask_all bit is ignored. bit 2 - range - configures the measurement range and data format of the temperature channels. ? ?0? (default) - the temperature measurement range is 0c to +127.875c and the data format is binary. ? ?1? -the temperature measuremen t range is -64c to +191.875c and the data format is offset binary (see table 5.3 ). bit 1 - davg_dis - disables the dynamic av eraging feature on all temperature channels. ? ?0? (default) - the dynamic averaging feature is enabled. all temperature c hannels will be converted with an averaging factor that is based on the conversion rate as shown in table 5.1 . table 6.4 configuration register addr r/w register b7 b6 b5 b4 b3 b2 b1 b0 default 03h r/w configuration mask_ all - alert/ comp - - range davg_ dis - 00h 09h
1c temperature sensor with hardware thermal shutdown datasheet revision 2.0 (08-10-12) 28 smsc emc1422 datasheet ? ?1? - the dynamic averaging featur e is disabled. all temperature channels will be converted with a maximum averaging factor of 1x (equivalent to 11-bit conversion). for higher conversion rates, this averaging factor will be reduced as shown in table 5.1 . 6.5 conversion rate register the conversion rate register controls how ofte n the temperature measurement channels are updated and compared against the limits. this register is fully accessible at either address. bits 3-0 - conv[3:0] - determines the conversion rate as shown in ta b l e 6.6 . table 6.5 conversion rate register addr r/w register b7 b6 b5 b4 b3 b2 b1 b0 default 04h r/w conversion rate - - - - conv[3:0] 06h (4/sec) 0ah table 6.6 conversion rate conv[3:0] conversions / second hex 3 2 1 0 0h 0 0 0 0 1 1h 0 0 0 1 1 2h 0 0 1 0 1 3h 0 0 1 1 1 4h 0 1 0 0 1 5h 0 1 0 1 2 6h 0 1 1 0 4 (default) 7h 0 1 1 1 8 8h 1 0 0 0 16 9h 1 0 0 1 32 ah 1 0 1 0 64 bh - fh all others 1
1c temperature sensor with hardware thermal shutdown datasheet smsc emc1422 29 revision 2.0 (08-10-12) datasheet 6.6 limit registers the device contains both high and low limits for al l temperature channels. if the measured temperature exceeds the high limit, then the corr esponding status bit is set and the alert pin is asserted. likewise, if the measured temperature is less than or equal to the low limit, the corresponding status bit is set and the alert pin is asserted. the data format for the limits must match the select ed data format for the temp erature so that if the extended temperature range is used, the limits mu st be programmed in the extended data format. the limit registers with multiple addresses are fully accessible at either address. 6.7 scratchpad registers the scratchpad registers are read write registers that are used for place holders to be software compatible with legacy programs. reading from th e registers will return what is written to them. table 6.7 temperature limit registers addr. r/w register b7 b6 b5 b4 b3 b2 b1 b0 default 05h r/w internal diode high limit 128643216 8 42 1 55h (85c) 0bh 06h r/w internal diode low limit 128643216 8 42 1 00h (0c) 0ch 07h r/w external diode high limit high byte 128643216 8 42 1 55h (85c) 0dh 13h r/w external diode high limit low byte 0.5 0.25 0.125 - - - - - 00h 08h r/w external diode low limit high byte 128643216 8 42 1 00h (0c) 0eh 14h r/w external diode low limit low byte 0.5 0.25 0.125 - - - - - 00h table 6.8 scratchpad register addr r/w register b7 b6 b5 b4 b3 b2 b1 b0 default 11h r/w scratchpad 7 6 5 4 3 2 1 0 00h 12h r/w scratchpad 7 6 5 4 3 2 1 0 00h
1c temperature sensor with hardware thermal shutdown datasheet revision 2.0 (08-10-12) 30 smsc emc1422 datasheet 6.8 therm limit registers 6.9 external diode fault register the external diode fault register indicates which of the external diodes caused the fault bit in the status register to be set. this r egister is cleared when it is read. bit 1 - flt - this bit is set if the external diode channel reported a diode fault. 6.10 software thermal shut down configuration register the software thermal shutdown configuration regist er controls whether any of the software channels will assert the sys_shdn pin. if a channel is enabled, the temperature is compared against the corresponding therm limit. if the measured temperature exceeds the therm limit, then the sys_shdn pin is asserted. this functionality is in addition to the hardware shutdown circuitry. bit 1 - extsys - configures the external diode channel to assert the sys_shdn pin based on its therm limit. ? ?0? (default) - the external diode channel is not linked to the sys_shdn pin. if the temperature exceeds its therm limit, the etherm status bit is set but the sys_shdn pin is not asserted. ? ?1? - the external diode channel is linked to the sys_shdn pin. if the temperature exceeds its therm limit, the etherm status bit is set and the sys_shdn pin is asserted. it will remain asserted until the temperature drops below its therm limit minus the therm hysteresis. table 6.9 therm limit registers addr. r/w register b7 b6 b5 b4 b3 b2 b1 b0 default 19h r/w external diode therm limit 128 64 32 16 8 4 2 1 55h (85c) 20h r/w internal diode therm limit 128 64 32 16 8 4 2 1 55h (85c) 21h r/w therm hysteresis 128 64 32 16 8 4 2 1 0ah (10c) table 6.10 external diode fault register addr. r/w register b7 b6 b5 b4 b3 b2 b1 b0 default 1bh r-c external diode fault ---- -- flt - 00h table 6.11 software thermal shutdown configuration register addr. r/w register b7 b6 b5 b4 b3 b2 b1 b0 default 1dh r/w software thermal shutdown configuration ---- -- extsys intsys 00h
1c temperature sensor with hardware thermal shutdown datasheet smsc emc1422 31 revision 2.0 (08-10-12) datasheet bit 0 - intsys - configures the inte rnal diode channel to assert the sys_shdn pin based on its therm limit. ? ?0? (default) - the internal diode channel is not li nked to the sys_shdn pin. if the temperature exceeds its therm limit, the itherm status bit is set but the sys_shdn pin is not asserted. ? ?1? - the internal diode cha nnel is linked to the sys_shdn pin. if the temperature exceeds its therm limit, the itherm stat us bit is set and the sys_shdn pin is asserted. it will remain asserted until the temperature drops below its therm limit minus the therm hysteresis. 6.11 hardware thermal shutdown limit register this read only register returns the hardware ther mal shutdown limit selected by the value of the pull- up resistors on the alert and sys_shdn pins. the data represents the hardware set temperature in c using the active temperature setting set by the range bit in the configuration register. see table 6.5 for the data format. when the external diode temperat ure exceeds this limit, the sys_shdn pin is asserted and will remain asserted until the external diode tem perature drops below th is limit minus 10c. 6.12 channel mask register the channel mask register controls individual channel masking. when a channel is masked, the alert pin will not be asserted when the masked channel reads a diode fault or out of limit error. the channel mask does not mask the sys_shdn pin. bit 1 - emask - masks the alert pin from asserting when the exte rnal diode channel is out of limit or reports a diode fault. ? ?0? (default) - the external diode channel will cause the alert pin to be asserted if it is out of limit or reports a diode fault. ? ?1? - the external diode channel will not cause the alert pin to be asserted if it is out of limit or reports a diode fault. bit 0 - intmask - masks the alert pin from asserting when the internal diode temperature is out of limit. ? ?0? (default) - the internal diode channel will cause the alert pin to be asserted if it is out of limit. ? ?1? - the internal diode channel will not cause the alert pin to be asserted if it is out of limit. table 6.12 hardware thermal shutdown limit register addr.r/w register b7b6b5b4b3b2b1b0default 1eh r hardware thermal shutdown limit 1286432168421 n/a table 6.13 channel mask register addr. r/w register b7 b6 b5 b4 b3 b2 b1 b0 default 1fh r/w channel mask ---- - - e mask int mask 00h
1c temperature sensor with hardware thermal shutdown datasheet revision 2.0 (08-10-12) 32 smsc emc1422 datasheet 6.13 consecutive alert register the consecutive alert register determines how many times an out-of-limit error or diode fault must be detected in consecutiv e measurements before the alert or sys_shdn pin is asserted. additionally, the consecutive alert register controls the smbus timeout functionality. an out-of-limit condition (i.e. hi gh, low, or fault) occurring on the same temperature channel in consecutive measurements will increm ent the consecutive alert counter. the counters will also be reset if no out-of-limit condition or diode fault condition occurs in a consecutive reading. when the alert pin is configured as an interrupt, when the consecutive alert counter reaches its programmed value, the following will occur: the status bit(s) for that channel and the last error condition(s) (i.e. ehigh) will be set to ?1?, the alert pin will be asserted, the consecutive alert counter will be cleared, and measurements will continue. when the alert pin is configured as a comparator, the consecutive alert counter will ignore diode fault and low limit errors and only increment if the measured temperature exceeds the high limit. additionally, once the consecutive alert counter reaches the pr ogrammed limit, the alert pin will be asserted, but the counter will not be reset. it will re main set until the temperature drops below the high limit minus the therm hysteresis value. for example, if the calrt[ 2:0] bits are set for 4 consecutive al erts, the high limits are set at 70c, and none of the channels are masked, then the alert pin will be asserted after the following four measurements: 1. internal diode reads 71c and the external diode reads 69c. consecutive alert counter for int is incremented to 1. 2. both the internal diode and the external diode read 71c. consecutive alert counter for int is incremented to 2and for ext is set to 1. 3. the external diode reads 71c and the internal diode reads 69c. consecutive alert counter for int is cleared and ext is incremented to 2. 4. the internal diode reads 71c and the external diode reads 71c. consecutive alert counter for int is set to 1 and ext is incremented to 3. 5. the internal diode reads 71c and the external diode reads 71c. consecutive alert counter for int is incremented to 2 and ext is incremented to 4. the appropriate status bits are set for ext and the alert pin is asserted. ext counter is reset to 0 and all other counters hold the last value until the next temperature measurement. bit 7 - timeout - determines whether the smbus timeout function is enabled. ? ?0? (default) - the smbus timeout feature is disabled. the smclk line can be held low indefinitely without the device resetting its smbus protocol. ? ?1? - the smbus timeout feature is enabled. if the smclk line is held low for more than 30ms, then the device will reset the smbus protocol. bits 6-4 cthrm[2:0] - determines the number of consecutive measurements that must exceed the corresponding therm limit and hardware thermal shutdown limit before the sys_shdn pin is asserted. all temperature channels us e this value to set the respec tive counters. the consecutive therm counter is incremented whenever any of the measurements exceed the corresponding therm limit or if the external diode measurement exceeds the hardware thermal shutdown limit. if the temperature drops below the therm limit or hardware thermal shutdown limit, then the counter is reset. if the progra mmed number of consecutive measurements exceed the therm limit table 6.14 consecutive alert register addr. r/w register b7 b6 b5 b4 b3 b2 b1 b0 default 22h r/w consecutive alert time out cthrm[2:0] calrt[2:0] - 70h
1c temperature sensor with hardware thermal shutdown datasheet smsc emc1422 33 revision 2.0 (08-10-12) datasheet or hardware thermal shutdown limit, and the appropriate channel is linked to the sys_shdn pin, then the sys_shdn pin will be asserted low. once the sys_shdn pin is asserted, the consecutive th erm counter will not reset until the corresponding temperature drops below the approp riate limit minus the corresponding hysteresis. the bits are decoded as shown in ta b l e 6.15 . the default setting is 4 consecutive out of limit conversions. bits 3-1 - calrt[2:0] - determine the number of consecutiv e measurements that must have an out of limit condition or diode fault before the alert pin is asserted. all temperature channels use this value to set the respective counters. the bits are decoded as shown in ta b l e 6.15 . the default setting is 1 consecutive out of limit conversion. application note: when measuring a 65nm intel cpus, the idealit y setting should be the default 12h. when measuring 45nm intel cpus, t he ideality setting should be 15h. 6.14 high limit status register the high limit status register contains the status bits that are set when a temperature channel high limit is exceeded. if any of these bi ts are set, then the high status bi t in the status register is set. reading from the high limit status register will clea r all bits if. reading from the register will also clear the high status bit in the status register. the alert pin will be set if the programmed number of consecutive alert counts have been met and any of these status bits are set. the status bits will remain set until read unless the alert pin is configured as a comparator output (see section 5.3.2 ). bit 1 - ehigh - this bit is set when the external diode channel exceeds its programmed high limit. bit 0 - ihigh - this bit is set when the internal diode channel exceeds its programmed high limit. table 6.15 consecutive alert / therm settings 210 number of consecutive out of limit measurements 000 1 (default for calrt[2:0]) 001 2 011 3 111 4 (default for cthrm[2:0]) table 6.16 high limit status register addr. r/w register b7 b6 b5 b4 b3 b2 b1 b0 default 35h r-c high limit status -- - - -- ehigh ihigh 00h
1c temperature sensor with hardware thermal shutdown datasheet revision 2.0 (08-10-12) 34 smsc emc1422 datasheet 6.15 low limit status register the low limit status register contains the status bits that are set when a temperature channel drops below the low limit. if any of these bi ts are set, then the lo w status bit in the stat us register is set. reading from the low limit status register will clear all bits. reading from the register will also clear the low status bit in the status register. the alert pin will be set if the programmed number of consecutive alert counts have been met and any of these status bits are set. the status bits will remain set until read unless the alert pin is configured as a comparator output (see section 5.3.2 ). bit 1 - elow - this bit is set when the external diode channel drops below its programmed low limit. bit 0 - ilow - this bit is set when the internal diode channel drops below its programmed low limit. 6.16 therm limit status register the therm limit status register contains the stat us bits that are set when a temperature channel therm limit is exceeded. if any of these bits are se t, then the therm status bit in the status register is set. reading from the therm limit status re gister will not clear the status bits. once the temperature drops below the therm limit minus th e therm hysteresis, the corresponding status bits will be automatically cleared. the therm bit in the status register will be cleared when all individual channel therm bits are cleared. bit 1 - etherm - this bit is set when the external diode channel exceeds its programmed therm limit. bit 0- itherm - this bit is set when the inter nal diode channel exceeds its programmed therm limit. 6.17 filter control register the filter configuration register controls the digital filter on the external diode channel. table 6.17 low limit status register addr. r/w register b7 b6 b5 b4 b3 b2 b1 b0 default 36h r-c low limit status ---- -- elow ilow 00h table 6.18 therm limit status register addr. r/w register b7 b6 b5 b4 b3 b2 b1 b0 default 37h r-c therm limit status -- - - -- etherm itherm 00h table 6.19 filter configuration register addr. r/w register b7 b6 b5 b4 b3 b2 b1 b0 default 40h r/w filter control - - - - - - filter[1:0] 00h
1c temperature sensor with hardware thermal shutdown datasheet smsc emc1422 35 revision 2.0 (08-10-12) datasheet bits 1-0 - filter[1:0] - control the level of digital filtering that is applied to the external diode temperature measurements as shown in table 6.20 . see figure 5.4 and figure 5.5 for examples on the filter behavior. 6.18 product id register the product id register holds a unique value that identifies the device. 6.19 smsc id register (feh) the manufacturer id register contains an 8 bit word that identifies the smsc as the manufacturer of the emc1422. table 6.20 filter settings filter[1:0] averaging 10 0 0 disabled (default) 0 1 level 1 10level 1 11level 2 table 6.21 product id register addrr/wregisterb7b6b5b4b3b2b1b0default fdh r product id 00100010 22h emc1422 table 6.22 manufacturer id register addr.r/wregisterb7b6b5b4b3b2b1b0default fehrsmsc id01011101 5dh
1c temperature sensor with hardware thermal shutdown datasheet revision 2.0 (08-10-12) 36 smsc emc1422 datasheet 6.20 revision register (ffh) the revision register contains an 8-bit word that identifies the die revision. it can be 01h or 04h. engineering note: table 6.23 revision register addr. r/w register b7 b6 b5 b4 b3 b2 b1 b0 default ffh r revision00000001 01h ffh r revision00000100 04h
1c temperature sensor with hardware thermal shutdown datasheet smsc emc1422 37 revision 2.0 (08-10-12) datasheet chapter 7 typical operating curves tem perature error vs. filter capacitor (2n3904, ta = 27c, t diode = 27c, vdd = 3.3v) -1.0 -0.8 -0.5 -0.3 0.0 0.3 0.5 0.8 1.0 0 1000 2000 3000 4000 filter capacitor (pf) temperature error (c) temperature error vs. ambient temperature (2n3904, t diode = 42.5c, vdd = 3.3v) -1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 -40 -25 -10 5 20 35 50 65 80 95 110 125 ambient temperature (c) temperature error (c) temperature error vs. external diode temperature (2n3904, ta = 42.5c, vdd = 3.3v) -1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 -40 -25 -10 5 20 35 50 65 80 95 110 125 external diode temperature (c) temperature error (c) temperature error vs. cpu temperature typical 65nm cpu from major vendor (ta = 27c, vdd = 3.3v, beta = 011, c filter = 470pf) -1 0 1 2 3 4 5 20 40 60 80 100 120 cpu temper atur e (c) temperature error (c) beta compensation disabled beta compensation enabled
1c temperature sensor with hardware thermal shutdown datasheet revision 2.0 (08-10-12) 38 smsc emc1422 datasheet temperature error vs. series resistance 0.0 0.2 0.4 0.6 0.8 1.0 0 50 100 150 200 0 20 40 60 80 100 120 rec enabled rec disabled series r (ohm) temperature error ( c) rec enabled temperature error ( c) rec disabled supply current vs. conversion rate 200 300 400 500 600 700 800 900 1000 1100 1200 1 2 4 8 163264 conversion rate supply current (ua ) dynamic averaging enabled dynamic averaging disabled
smsc emc1422 39 revision 2.0 (08-10-12) datasheet 1c temperature sensor with hardware thermal shutdown datasheet chapter 8 package information figure 8.1 8-pin msop / tssop package - see spec front page for revision history -- c see detail "a" e d e1 e pin 1 identifier area (d/2 x e1/2) 8x b l l1 0.25 0 - 8 dim and tol per asme y14. 5m - 1994 finish material decimal x.x x.xx x.xxx 80 arkay drive hauppauge, ny 11788 usa angular print with "scale to fit" do not scale drawing checked approved name drawn dwg n umber scale title date std compliance unless otherwise specified dimensions are in millimeters and tolerances are: third angle projection rev sheet revision description revision history released by date package outline 8 pin tssop, 3x3 mm body, 0.65 mm pitch 1 - - 0.1 0.05 0.025 s.k.iliev s.k.iliev s.k.iliev 7/07/04 7/05/04 1:1 7/05/04 mo-8-tssop-3x3 jedec: mo-187 / d 1 of 1 d c seating plane a a2 a1 seating plane side view ccc c gauge plane h 3-d view top view c 3 2 end view 4 3 5 detail "a" scale: 3/1 notes: 1. all dimensions are in millimeter. 2. tolerance on the true position of the leads is 0.065mm maximum. 3. package body dimensions "d" and "e1" do not include mold protrusions or flash. maximum mold protrusions or flash is 0.15 mm (0.006 inches) per end and side. dimensions "d" and "e1" are determined at datum plane "h". 4. dimension for foot length "l" is measured at the gauge plane 0.25mm above the seating plane. 5. details of pin 1 identifier are optional, but must be located within the zone indicated.
1c temperature sensor with hardware thermal shutdown datasheet revision 2.0 (08-10-12) 40 smsc emc1422 datasheet 8.1 package markings all devices will be marked on the first line of the t op side with ?1422?. on the second line, they will be marked with the appropriate -x number (-1, -2, et c), the functional revision ?b? and country code (cc). .
1c temperature sensor with hardware thermal shutdown datasheet smsc emc1422 41 revision 2.0 (08-10-12) datasheet chapter 9 datasheet revision history table 9.1 customer revision history revision level & date secti on/figure/entr y correction rev. 2.0 (08-10-12) table 3.3, "smbus electrical specifications" added conditions for t hd:dat . data hold time minimum of 0.3s is requ ired when receiving from the master. data hold time is 0s min when transmitting to the master. section 6.20, "revision register (ffh)" added row to indicate that revision id can be 04h. revision id may be 04h or 01h. rev. 1.36 (07-02-09) table 2.1, "emc1422 pin description" in pin description table, added to function column: ?requires pull-up resistor? for smdata and smclk pins table 2.1, "emc1422 pin description" identified 5v tolerant pins. added the following application note below table: ?for the 5v tolerant pins that have a pull-up resistor (smclk, smdata, sys_shdn , and alert ), the voltage difference between vdd and the pull-up voltage must never exceed 3.6v.? table 3.1, "absolute maximum ratings" updated voltage limits for 5v tolerant pins with pull-up resistors. added the following note below table: ?for the 5v tolerant pins that have a pull-up resistor (smclk, smdata, sys_shdn , and alert ), the pull-up voltage must not exceed 3. 6v when the device is unpowered.? table 3.2, "electrical specifications" added leakage current. rev. 1.35 (04-17-09) table 2.1, "emc1422 pin description" ?preliminary? removed from table title rev. 1.34 (02-27-09) table 5.3, "temperature data format" extended range for -1 updated from 001 1111 1111 to 001 1111 1000


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