ame, inc. 1 ame8510 / 8520 / 8530 micropower m m m m m p watch dog timer n n n n n features l small packages: sot-23-5 l 7 voltage threshold options l tight voltage threshold tolerance --- 1.50% l 12 output driver configuration options l wide temperature range -------- -45 o c to 85 o c l low temperature coefficient --- 100ppm/ o c (max) l low quiescent current < 3.0 m a l 3 bonding options n n n n n general description the ame8510/8520/8530 family allows the user to cus- tomize the cpu monitoring function without any external components. the user has a large choice of reset volt- age thresholds and output driver configurations, all of which are preset at the factory. each wafer is trimmed to the customer's specifications. these circuits will ignore fast negative going transients on v dd . the state of the reset output is guaranteed to be correct down to 1v. after v dd crosses above a factory preset threshold, the ame8510/8520/8530 assert a reset signal. after a pre- determined time (the reset interval) the reset is deasserted. if v dd ever drops below the threshold volt- age a reset is asserted immediately. in addition to a supply monitoring function the ame8510/8520 also moni- tor transitions at the watch dog (wdi) input. if a logic transition does not occur at the wdi pin within a certain time interval (the watchdog interval) then a reset is as- serted. the reset deasserts after the reset interval, as explained earlier. the ame8510/8530 can both assert a reset manually by pulling the mrb input to ground. space saving sot25 packages and micropower quies- cent current make this family a natural for portable bat- tery powered equipment. n n n n n applications l motherboards l computer peripherals l portable electronics l applications using cpus l consumer electronics n n n n n pin configuration sot-25 top view ame8510 ame8511 ame8510 v dd wdi reset/ resetb gnd mrb ame8510 ame8511 ame8520 v dd wdi gnd reset/ resetb resetb/ reset v dd mrb gnd reset/ resetb resetb/ reset ame8530 ame851 ame8530
ame, inc. 2 ame8510 / 8520 / 8530 micropower m m m m m p watch dog timer ame8530 ame851 8510/20/30 wdi/mrb pin 1 pin 3 gnd v dd n ordering information ame8510aeev x x x xx ame8520aeev x x x xx ame8530aeev x x x xx v dd threshold voltage 22: v th =2.19v 23: v th =2.32v 26: v th =2.63v 29: v th =2.93v 31: v th =3.08v 44: v th =4.38v 46: v th =4.63v watch dog interval (t wdnom ) e: t d =1760ms x: without wdi option reset time (t d2nom ) f: t d =210ms output driver option polarity * polarity * a : resetb pp n/ a n/ a b: resetb od n/a n/a c: reset pp n/ a n/ a --for example-- d: reset od n/a n/a ame8520aeevefe29 means: e: resetb pp reset pp output at pin 1 is resetb, push pull f: resetb pp reset od output at pin 3 is reset, push pull g: resetb od reset pp * output driver chart explanation: reset time is 210ms h: resetb od reset od pp = push pull output watch dog interval is 1760ms i: reset pp resetb pp od = open drain output v dd threshold voltage is 2.93v j: reset pp resetb od n/a = not available (8510) no temperature shutdow n k: reset od resetb pp reset = active high l : reset od resetb od resetb = a c t i v e l o w please consult ame sales office or authorized rep. for other reset time interval and watch dog time interval. pi n 1 pi n 3
ame, inc. 3 ame8510 / 8520 / 8530 micropower m m m m m p watch dog timer n n n n n absolute maximum ratings n n n n n recommended operating conditions n n n n n thermal information caution: stress above the listed absolute rating may cause permanent damage to the device maximum unit 6v b maximum unit 256 o c / w 150 o c 300 o c parameter supply voltage esd classification parameter ambient temperature range junction temperature supply voltage parameter rating 0.9 - 5 v thermal resistance (sot-25) maximum lead temperature ( 10 sec) maximum junction temperature - 40 to +85 o c - 40 to +125 o c
ame, inc. 4 ame8510 / 8520 / 8530 micropower m m m m m p watch dog timer n n n n n electrical specifications t a = 25 o c unless otherwise noted parameter symbol min typ max units v dd range v range 15.5v supply current i dd 310 m a reset threshold* v th v th - 1.5% v th + 1.5% v resetb output voltage hgh v dd >v th max reset output voltage hgh v dd v th max v dd to reset delay t d1 v dd = v th - 100mv 40 m s reset timeout period* t d2 ta=-40~85 0 c version f 140 210 280 ms watch dog timeout period* t wd 1120 1760 2400 ms wdi pul s e wi dth t wdi 50 ns wdi il 0.7 v wdi ih 0.8v dd v i il wdi = 0v -15 -8 i ih wdi = v dd = 5.0v 8 15 mr b il 0.7 mr b ih 0.8v dd mrb pulse width t wmrb 1 m s mrb noise immunity (pulse width with no reset) 100 ns mrb to reset delay t dmrb 500 ns mrb pull up resistance 80 120 kohm * see the chart on page 2 for available values of this parameter. v oh v v ol v 0.5 0.8v dd m a v mrb input threshold wdi input threshold wdi input current v dd = v th x 1.2 v dd = v th x 1.2 version e test conditions wdi and mrb unconnected i source =0.5ma, ta=-40~85 0 c i snk =1.2ma, ta=-40~85 0 c
ame, inc. 5 ame8510 / 8520 / 8530 micropower m m m m m p watch dog timer n n n n pin description ground pin number this pin may be either reset or resetb. resetb is active low. in the case of the ame8520 and ame8530 this pin will always be the opposite polarity from pin 3. this pin can be push/pull or open drain. 111 reset/ resetb 222 this pin may be either resetb or reset. reset is active high. in the case of the ame8520 and ame8530 this pin will always be the opposite polarity from pin 1. this pin can be either push/pull or open drain. watch dog input. any transition on this pin will reset the watch dog timer. if this pin remains high or low for longer than the watch dog interval then a reset is asserted. float or tristate this pin to disable the watch dog feature. manual reset. active low. pulling this pin low forces a reset. after a low to high transition reset remains asserted for exactly one reset timeout period. this pin is internally pulled high. if this function is unused then float this pin or tie it to v dd . positive power supply. a reset is asserted after this voltage drops below a predetermined level. after v dd rises above that level reset remains asserted until the end of the reset timeout period. gnd n/a 3 3 reset/ resetb 34 n/a mrb 44n/awdi 555v dd name description ame8510 ame8520 ame8530
ame, inc. 6 ame8510 / 8520 / 8530 micropower m m m m m p watch dog timer n n n n n detailed description the ame8510/8520/8530 are designed to interface with the reset input of a microprocessor and to prevent cpu execution errors due to power up, power down, and other power supply errors. the ame8510/8520 also monitor the cpu health by checking for signal transitions from the cpu at the wdi input. reset output each output pin in the family can be configured to be either push/pull or open drain. in addition each output may be either active high or active low with the condi- tion that parts with two outputs must have opposite po- larities. active high reset outputs are denoted as re- set. active low reset outputs are denoted as resetb. the selection guide on page 2 of this data sheet shows all possible combinations of output driver configuration. a reset will be asserted if any of three things happen: 1) v dd drops below the threshold (v th ) 2) the mrb pin is pulled low. 3) the wdi pin does not detect a transition within the watch dog interval (t wd ). the reset will remain asserted for the prescribed reset interval after: 1) v dd rises above the threshold (v th ) 2) mrb goes high 3) the watch dog timer has timed out causing the reset to assert. reset timing diagram manual reset input the ame8510 and ame8530 feature a manual reset fea- ture (mrb). a logic low on the mrb pin asserts a reset. the reset remains asserted as long as the mrb pin re- mains low. after the mrb pin transitions to a high state the reset remains asserted for the prescribed reset inter- val (t d2 ). the mrb pin is internally pulled up to vdd by a 100k w resistor. it is internally debounced to reject switching transients. the mrb pin is esd protected by diodes connected to v dd and gnd. so the mrb pin should never be driven higher than v dd or lower than gnd. watchdog input the ame8510 and ame8520 are equipped with a watch- dog input (wdi). if the microprocessor does not produce a valid logic edge at the the watchdog input (wdi) within the prescribed watchdog interval (t wd ) then a reset as- serts. the reset remains asserted for the required reset interval (t d2 ) at the end of the reset interval the reset is deasserted and the watchdog interval timer starts again from zero. if the watchdog input is left unconnected or is connected to a tri-stated buffer the watchdog function is disabled. as soon as the wdi input is driven either low or high the watchdog function resumes with the watchdog timer set to zero. watchdog timing diagram wdi resetb vdd t wd t d2 t d2 v th v dd t d2 v release resetb v th t d1 t d2 t d1 reset 50% 50% 50% 50%
ame, inc. 7 ame8510 / 8520 / 8530 micropower m m m m m p watch dog timer watchdog input current n n n n n detailed description (contd.) the watchdog input pin (wdi) typically sources/sinks 8 m a when driven high or low. so from a power dissipation point of view the duty cycle of the waveform at wdi is unimportant. when the wdi pin is floating or tri-stated the power supply current falls to less than 3.0 m a. glitch rejection the ame8510/8520/8530 family will reject negative go- ing transients on the v dd line to some extent. the smaller the duration of the transient the larger its amplitude may be without triggering a reset. the glitch rejection chart in the graphs section of this datasheet shows the rela- tion between glitch amplitude and allowable glitch dura- tion to avoid unintended resets. accurate output state at low v dd with v dd voltage on the order of the mos transistor thresh- old (<1.0v) the outputs of the ame8510/8520/8530 may become undefined. for parts with active low output (resetb) a resistor placed between resetb and gnd on the order of 100k w will ensure that the resetb out- put stays low when v dd is lower than the threshold volt- age of the part. in a like manner a resistor on the order of 100k w when placed between reset and v dd will en- sure parts with active high output (reset) will remain high when v dd is lower than the threshold voltage of the part.
ame, inc. 8 ame8510 / 8520 / 8530 micropower m m m m m p watch dog timer 0 20 40 60 80 100 120 140 0.01 0.1 1 glitch rejection glitch duration ( m m m m s) glitch amplitude (v) 190 195 200 205 210 215 220 -45 -5 25 55 85 115 temperature ( 0 c) reset time (ms) reset time vs temperature vth=2.63v 2.10 2.15 2.20 2.25 2.30 2.35 -45 -5 25 55 85 115 temperature ( 0 c) supply current @ 5v (ua ) idd vs temperature vth=2.63v 2.630 2.632 2.634 2.636 2.638 2.640 2.642 2.644 2.646 2.648 2.650 -45-5 25 5585115 temperature ( 0 c) reset vth (v) reset vth vs temperature vth=2.63v 0.220 0.225 0.230 0.235 0.240 0.245 0.250 0.255 0.260 0.265 -45 -5 25 55 85 115 temperature ( 0 c) reset vol @ 0.8ma (v) resetb vol vs temperature vth=2.63v
ame, inc. 9 ame8510 / 8520 / 8530 micropower m m m m m p watch dog timer sot-25 n n n n n package dimension min max min max a 1.00 1.45 0.0394 0.0571 a 1 0.00 0.15 0.0000 0.0591 a2 0.70 1.25 0.0276 0.0492 b 0.35 0.55 0.0138 0.0217 c 0.08 0.25 0.0031 0.0098 d 2.70 3.10 0.1063 0.1220 e 1.40 1.80 0.0551 0.0709 e h 2.60 3.00 0.1024 0.1181 l 0.30 - 0.0118 - q1 q1 q1 q1 0 10 0 10 s 1 0.85 1.05 0.0335 0.0413 1.90 bsc 0.07480 bsc symbols millimeters inches
life support policy: these products of ame, inc. are not authorized for use as critical components in life-support devices or systems, without the express written approval of the president of ame, inc. ame, inc. reserves the right to make changes in the circuitry and specifications of its devices and advises its customers to obtain the latest version of relevant information. ? ame, inc., january 2002 document: 2007-ds8510/8520/8530-b u.s. headquarters corporate headquarters analog microelectronics, inc. ame, inc. 3100 de la cruz blvd. suite 201 2f, 189 kang-chien road, nei-hu dist. santa clara, ca. 95054-2046 taipei 114, taiwan, r.o.c. tel : (408) 988-2388 tel : 886 2 2627-8687 fax: (408) 988-2489 fax : 886 2 2659-2989 www.ame.com.tw e-mail: info@ame.com.tw
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