remark: bold type = generated by slave device. fig 8. write mode (output) a5 a4 a3 a2 a1 a0 0 a sa6 slave address start condition r/w acknowledge from slave 002aah349 p6 1p7 data 1 a acknowledge from slave 12345678 scl 9 sda a acknowledge from slave write to port data output from port t v(q) p5 data 2 data 2 valid p4 p3 p2 p1 p0 p7 p4 p3 p2 p1 p0 p6 p5 0 t v(q) data 1 valid p5 output voltage i trt(pu) i oh p5 pull-up output current t d(rst) int
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 9 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt 8.3 reading from a port (input mode) the port must have been previously writt en to logic 1, which is the condition after power-on reset. to enter the read mode the master (microcontroller) addresses the slave device and sets the last bit of the address byte to logic 1 (address byte read). the slave will acknowledge and then send the data byte to the ma ster. the master will nack and then send the stop condition or ack and read the input register again. the read of any pin be ing used as an output will indicate high or low depending on the actual state of the pin. if the data on the input port changes faster than the master can read, this data may be lost. the data 2 and data3 are lost because these data did not meet the setup time and hold time (see figure 9 ). simple code for read mode: < ack > < data in > ... < data in > < data in >

remark: bold type = generated by slave device. 8.4 power-on reset when power is applied to v dd , an internal power-on reset (por) holds the pcf8574/74a in a reset condition until v dd has reached v por . at that point, the reset condition is released and th e pcf8574/74a registers and i 2 c-bus/smbus state machine will initialize to their default states of all i/o s to inputs with weak current source to v dd . thereafter v dd must be lowered below v por and back up to the operation voltage for power-on reset cycle. a low-to-high transition of sda while scl is high is defined as the stop condition (p). transfer of data can be stopped at any moment by a stop condition. when this occurs, data present at the last acknowledge phase is valid (output mode). input data is lost. fig 9. read mode (input) a5 a4 a3 a2 a1 a0 1 a sa6 slave address start condition r/w acknowledge from slave 002aah383 data from port a acknowledge from master sda 1 no acknowledge from master read from port data at port data from port data 1 data 4 int data 4 data 2 data 3 p stop condition t v(int) t rst(int) t h(d) t su(d) t rst(int) data 1
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 10 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt 8.5 interrupt output (int ) the pcf8574/74a provides an open-drain output (int ) which can be fed to a corresponding input of the microcontroller (see figure 10 ). as soon as a port input is changed, the int will be active (low) and notify the microcontroller. an interrupt is genera ted at any rising or falling edge of the port inputs. after time t v(q) , the signal int is valid. the interrupt will reset to high when data on th e port is changed to the original setting or data is read or written by the master. in the write mode, the interrupt may be reset (high) on the rising edge of the acknowledge bit of the address byte and also on the rising edge of the write to port pulse. the interrupt will always be reset (high) on the falling edge of the writ e to port pulse (see figure 8 ). the interrupt is reset (high) in the read mode on the rising edge of the read from port pulse (see figure 9 ). during the interrupt reset, any i/o change close to the read or write pulse may not generate an interrupt, or the interrupt will have a very short pulse. after the interrupt is reset, any change in i/os will be detected and transmitted as an int . at power-on reset all ports are in input mode and the initial state of the ports is high, therefore, for any port pin that is pulled low or driven low by external source, the interrupt output will be active (output low). fig 10. application of multiple pcf8574/74as with interrupt 002aad634 v dd microcontroller int pcf8574 int pcf8574 int device 1 device 2 pcf8574a int device 16
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 11 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt 9. characteristics of the i 2 c-bus the i 2 c-bus is for 2-way, 2-wire communication between different ics or modules. the two wires are a serial data line (sda) and a serial clock line (scl). both lines must be connected to a positive supply via a pull-up re sistor when connected to the output stages of a device. data transfer may be initiated only when the bus is not busy. 9.1 bit transfer one data bit is transferred during each clock pulse. the data on the sda line must remain stable during the high period of the clock pulse as changes in the data line at this time will be interpreted as control signals (see figure 11 ). 9.1.1 start and stop conditions both data and clock lines remain high when the bus is not busy. a high-to-low transition of the data line while the clock is hi gh is defined as the start condition (s). a low-to-high transition of the data line while the clock is high is defined as the stop condition (p) (see figure 12 ). 9.2 system configuration a device generating a message is a ?transmitter ?; a device receiving is the ?receiver?. the device that controls the message is the ?master? and the devices which are controlled by the master are the ?slaves? (see figure 13 ). fig 11. bit transfer mba607 data line stable; data valid change of data allowed sda scl fig 12. definition of start and stop conditions mba608 sda scl p stop condition s start condition
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 12 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt 9.3 acknowledge the number of data bytes transferred betwe en the start and the stop conditions from transmitter to receiver is not limited. ea ch byte of eight bits is followed by one acknowledge bit (see figure 14 ). the acknowledge bit is an active low level (generated by the receiving device) that indicates to the transmitter that t he data transfer was successful. a slave receiver which is addressed must gen erate an acknowledge af ter the reception of each byte. also a master must generate an acknowledge after the reception of each byte that has been clocked out of the slave tran smitter. the device that wants to issue an acknowledge bit has to pull down the sda line during the acknowledge clock pulse, so that the sda line is stable low during the high period of the acknowledge bit related clock pulse; set-up and hold times must be taken into account. a master receiver must signal an end of data to the transmitter by not generating an acknowledge on the last byte that has been cloc ked out of the slave. in this event, the transmitter must leave the data line high to enable the master to generate a stop condition. fig 13. system configuration 002aaa966 master transmitter/ receiver slave receiver slave transmitter/ receiver master transmitter master transmitter/ receiver sda scl i 2 c-bus multiplexer slave fig 14. acknowledgement on the i 2 c-bus 002aaa987 s start condition 9 8 2 1 clock pulse for acknowledgement not acknowledge acknowledge data output by transmitter data output by receiver scl from master
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 13 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt 10. application design-in information 10.1 bidirectional i/o expander applications in the 8-bit i/o expander application shown in figure 15 , p0 and p1 are inputs, and p2 to p7 are outputs. when used in this configuration, during a write, the input (p0 and p1) must be written as high so the external devices fully control the input ports . the desired high or low logic levels may be written to the ports used as outputs (p2 to p7). if 10 ? a internal output high is not enough current source, the port needs external pull-up resistor. during a read, the logic leve ls of the external de vices driving the input ports (p0 and p1) and the previ ous written logic level to the output ports (p2 to p7) will be read. the gpio also has an interrupt line (int ) that can be connected to the interrupt logic of the microcontroller. by sending an interrupt signal on this lin e, the remote i/o informs the microprocessor that there has been a change of data on its ports without having to communicate via the i 2 c-bus. 10.2 how to read and writ e to i/o expander (example) in the application example of pcf8574 shown in figure 15 , the microcontroller wants to control the p3 switch on and the p7 led on when the temperature sensor p0 changes. 1. when the system power on: core processor needs to issue an initial command to set p0 and p1 as inputs and p[7:2] as outputs with value 1010 00 (led off, mp3 off, camera on, audio off, switch off and latch off). 2. operation: when the temperature changes above the th reshold, the temperature sensor signal will toggle from high to low. the int will be activated and notifies the ?core processor? that there have been changes on the input pins. read the input register. if p0 = 0 (temperature sensor has changed), then turn on led and turn on switch. 3. software code: //system power on // write to pcf8574 with data 1010 0011b to set p[7:2] outputs and p[1:0] inputs <0100 0000> <1010 0011>

//initial setting for pcf9574 fig 15. bidirectional i/o expander application 002aah384 v dd temperature sensor battery status control for latch control for switch control for audio control for camera control for mp3 p0 p1 p2 p3 p4 p5 p6 p7 v dd sda scl int a0 a1 a2 core processor v dd
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 14 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt while (int == 1); //monitor the interrupt pin. if int = 1 do nothing //when int = 0 then read input ports <1010 0010>

//read pcf8574 data if (p0 == 0) //temperature sensor activated { // write to pcf8574 with data 0010 1011b to turn on led (p7), on switch (p3) and keep p[1:0] as input ports. <0100 0000> <0010 1011>

// write to pcf8574 } 10.3 high current-drive load applications the gpio has a minimum guaranteed sinkin g current of 10 ma per bit at 5 v. in applications requiring additional drive, two por t pins may be connected together to sink up to 20 ma current. both bits mu st then always be turned on or off together. up to five pins can be connected together to drive 80 ma, which is the device recommended total limit. each pin needs its own limiting resistor as shown in figure 16 to prevent damage to the device should all ports not be turned on at the same time. 10.4 migration path nxp offers newer, more capable drop-in replacements for the pcf8574/74a in newer space-saving packages. pca9670 replaces the interrupt output of the pca9674 with hardware reset input to retain the maximum number of addresses and the pca9672 replaces address a2 of the pca9674 with hardware reset input to reta in the interrupt but limit the number of addresses. fig 16. high current-drive load application 002aah385 v dd p0 p1 p2 p3 p4 p5 p6 p7 v dd sda scl int a0 a1 a2 core processor v dd load table 6. migration path type number i 2 c-bus frequency voltage range number of addresses per device interrupt reset total package sink current pcf8574/74a 100 khz 2.5 v to 6 v 8 yes no 80 ma pca8574/74a 400 khz 2.3 v to 5.5 v 8 yes no 200 ma pca9674/74a 1 mhz fm+ 2.3 v to 5.5 v 64 yes no 200 ma pca9670 1 mhz fm+ 2.3 v to 5.5 v 64 no yes 200 ma pca9672 1 mhz fm+ 2.3 v to 5.5 v 16 yes yes 200 ma
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 15 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt 11. limiting values 12. thermal characteristics table 7. limiting values in accordance with the absolute maximum rating system (iec 60134). symbol parameter conditions min max unit v dd supply voltage ? 0.5 +7 v i dd supply current - ? 100 ma i ss ground supply current - ? 100 ma v i input voltage v ss ? 0.5 v dd +0.5 v i i input current - ? 20 ma i o output current - ? 25 ma p tot total power dissipation - 400 mw p/out power dissipation per output - 100 mw t j(max) maximum junction temperature - 125 ?c t stg storage temperature ? 65 +150 ?c t amb ambient temperature operating ? 40 +85 ?c table 8. thermal characteristics symbol parameter conditions typ unit r th(j-a) thermal resistance from junction to ambient so16 package 115 ? c/w ssop20 package 136 ? c/w
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 16 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt 13. static characteristics [1] the power-on reset circuit resets the i 2 c-bus logic at v dd pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 17 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt 14. dynamic characteristics [1] all the timing values are valid within the operating supply voltage and ambient temperature range and refer to v il and v ih with an input voltage swing of v ss to v dd . table 10. dynamic characteristics v dd = 2.5 v to 6 v; v ss =0v; t amb = ? 40 ? c to +85 ? c; unless otherwise specified. symbol parameter conditions min typ max unit i 2 c-bus timing [1] (see figure 17 ) f scl scl clock frequency - - 100 khz t buf bus free time between a stop and start condition 4.7 - - ? s t hd;sta hold time (repeated) start condition 4 - - ? s t su;sta set-up time for a repeated start condition 4.7 - - ? s t su;sto set-up time for stop condition 4 - - ? s t hd;dat data hold time 0 - - ns t vd;dat data valid time - - 3.4 ? s t su;dat data set-up time 250 - - ns t low low period of the scl clock 4.7 - - ? s t high high period of the scl clock 4 - - ? s t r rise time of both sda and scl signals - - 1 ? s t f fall time of both sda and scl signals - - 0.3 ? s port timing (see figure 8 and figure 9 ) t v(q) data output valid time c l ? 100 pf - - 4 ? s t su(d) data input set-up time c l ? 100 pf 0 - - ? s t h(d) data input hold time c l ? 100 pf 4 - - ? s interrupt int timing (see figure 9 ) t v(int) valid time on pin int from port to int ; c l ? 100 pf --4 ? s t rst(int) reset time on pin int from scl to int ; c l ? 100 pf --4 ? s
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 18 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt rise and fall times refer to v il and v ih . fig 17. i 2 c-bus timing diagram 002aab175 protocol start condition (s) bit 7 msb (a7) bit 6 (a6) bit 0 (r/w) acknowledge (a) stop condition (p) scl sda t hd;sta t su;dat t hd;dat t f t buf t su;sta t low t high t vd;ack t su;sto 1 / f scl t r t vd;dat 0.3 v dd 0.7 v dd 0.3 v dd 0.7 v dd
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 19 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt 15. package outline fig 18. package outline sot38-4 (dip16) references outline version european projection issue date iec jedec jeita sot38-4 95-01-14 03-02-13 m h c (e ) 1 m e a l seating plane a 1 w m b 1 b 2 e d a 2 z 16 1 9 8 e pin 1 index b 0 5 10 mm scale note 1. plastic or metal protrusions of 0.25 mm (0.01 inch) maximum per side are not included. unit a max. 12 b 1 (1) (1) (1) b 2 cd e e m z h l mm dimensions (inch dimensions are derived from the original mm dimensions) a min. a max. b max. w m e e 1 1.73 1.30 0.53 0.38 0.36 0.23 19.50 18.55 6.48 6.20 3.60 3.05 0.254 2.54 7.62 8.25 7.80 10.0 8.3 0.76 4.2 0.51 3.2 inches 0.068 0.051 0.021 0.015 0.014 0.009 1.25 0.85 0.049 0.033 0.77 0.73 0.26 0.24 0.14 0.12 0.01 0.1 0.3 0.32 0.31 0.39 0.33 0.03 0.17 0.02 0.13 dip16: plastic dual in-line package; 16 leads (300 mil) sot38-4
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 20 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt fig 19. package outline sot162-1 (so16) unit a max. a 1 a 2 a 3 b p cd (1) e (1) (1) eh e ll p q z ywv references outline version european projection issue date iec jedec jeita mm inches 2.65 0.3 0.1 2.45 2.25 0.49 0.36 0.32 0.23 10.5 10.1 7.6 7.4 1.27 10.65 10.00 1.1 1.0 0.9 0.4 8 0 o o 0.25 0.1 dimensions (inch dimensions are derived from the original mm dimensions) note 1. plastic or metal protrusions of 0.15 mm (0.006 inch) maximum per side are not included. 1.1 0.4 sot162-1 8 16 w m b p d detail x z e 9 1 y 0.25 075e03 ms-013 pin 1 index 0.1 0.012 0.004 0.096 0.089 0.019 0.014 0.013 0.009 0.41 0.40 0.30 0.29 0.05 1.4 0.055 0.419 0.394 0.043 0.039 0.035 0.016 0.01 0.25 0.01 0.004 0.043 0.016 0.01 x a a 1 a 2 h e l p q e c l v m a (a ) 3 a 0 5 10 mm scale so16: plastic small outline package; 16 leads; body width 7.5 mm sot162-1 99-12-27 03-02-19
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 21 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt fig 20. package outline sot266-1 (ssop20) unit a 1 a 2 a 3 b p cd (1) e (1) (1) eh e ll p qz ywv references outline version european projection issue date iec jedec jeita mm 0.15 0 1.4 1.2 0.32 0.20 0.20 0.13 6.6 6.4 4.5 4.3 0.65 1 0.2 6.6 6.2 0.65 0.45 0.48 0.18 10 0 o o 0.13 0.1 dimensions (mm are the original dimensions) note 1. plastic or metal protrusions of 0.20 mm maximum per side are not included. 0.75 0.45 sot266-1 mo-152 99-12-27 03-02-19 w m a a 1 a 2 b p d h e l p q detail x e z e c l v m a x (a ) 3 a y 0.25 11 0 20 11 pin 1 index 0 2.5 5 mm scale ssop20: plastic shrink small outline package; 20 leads; body width 4.4 mm sot266-1 a max. 1.5
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 22 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt 16. handling information all input and output pins are protected ag ainst electrostatic discharge (esd) under normal handling. when handling ensure that the appropriate precautions are taken as described in jesd625-a or equivalent standards. 17. soldering of smd packages this text provides a very brief insight into a complex technology. a more in-depth account of soldering ics can be found in application note an10365 ?surface mount reflow soldering description? . 17.1 introduction to soldering soldering is one of the most common methods through which packages are attached to printed circuit boards (pcbs), to form electr ical circuits. the soldered joint provides both the mechanical and the electrical connection. th ere is no single sold ering method that is ideal for all ic packages. wave soldering is often preferred when through-hole and surface mount devices (smds) are mixed on one printed wiring board; however, it is not suitable for fine pitch smds. reflow soldering is ideal for the small pitches and high densities that come with increased miniaturization. 17.2 wave and reflow soldering wave soldering is a joining technology in which the joints are made by solder coming from a standing wave of liquid solder. the wave soldering process is suitable for the following: ? through-hole components ? leaded or leadless smds, which are glued to the surface of the printed circuit board not all smds can be wave soldered. packages with solder balls, and some leadless packages which have solder lands underneath the body, cannot be wave soldered. also, leaded smds with leads having a pitch smaller than ~0.6 mm cannot be wave soldered, due to an increased pr obability of bridging. the reflow soldering process involves applying solder paste to a board, followed by component placement and exposure to a temperature profile. leaded packages, packages with solder balls, and leadless packages are all reflow solderable. key characteristics in both wave and reflow soldering are: ? board specifications, in cluding the board finish , solder masks and vias ? package footprints, including solder thieves and orientation ? the moisture sensitivit y level of the packages ? package placement ? inspection and repair ? lead-free soldering versus snpb soldering 17.3 wave soldering key characteristics in wave soldering are:
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 23 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt ? process issues, such as application of adhe sive and flux, clinching of leads, board transport, the solder wave parameters, and the time during which components are exposed to the wave ? solder bath specifications, including temperature and impurities 17.4 reflow soldering key characteristics in reflow soldering are: ? lead-free versus snpb solderi ng; note that a lead-free reflow process usually leads to higher minimum peak temperatures (see figure 21 ) than a snpb process, thus reducing the process window ? solder paste printing issues including smearing, release, and adjusting the process window for a mix of large and small components on one board ? reflow temperature profile; this profile includ es preheat, reflow (in which the board is heated to the peak temperature) and cooling down. it is imperative that the peak temperature is high enough for the solder to make reliable solder joints (a solder paste characteristic). in addition, the peak temperature must be low enough that the packages and/or boards are not damaged. the peak temperature of the package depends on package thickness and volume and is classified in accordance with ta b l e 11 and 12 moisture sensitivity precautions, as indicat ed on the packing, must be respected at all times. studies have shown that small packages reach higher temperatures during reflow soldering, see figure 21 . table 11. snpb eutectic process (from j-std-020d) package thickness (mm) package reflow temperature ( ?c) volume (mm 3 ) < 350 ? 350 < 2.5 235 220 ? 2.5 220 220 table 12. lead-free process (from j-std-020d) package thickness (mm) package reflow temperature ( ?c) volume (mm 3 ) < 350 350 to 2000 > 2000 < 1.6 260 260 260 1.6 to 2.5 260 250 245 > 2.5 250 245 245
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 24 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt for further information on temperature profiles, refer to application note an10365 ?surface mount reflow soldering description? . 18. soldering of throug h-hole mount packages 18.1 introduction to solderi ng through-hole mount packages this text gives a very brief insight into wave, dip and manual soldering. wave soldering is the preferred method for mounting of through-hole mount ic packages on a printed-circuit board. 18.2 soldering by dipping or by solder wave driven by legislation and environmental forc es the worldwide use of lead-free solder pastes is increasing. typical dwell time of the leads in the wave ranges from 3 seconds to 4 seconds at 250 ? c or 265 ? c, depending on solder material applied, snpb or pb-free respectively. the total contact time of successive solder waves must not exceed 5 seconds. the device may be mounted up to the seati ng plane, but the temperature of the plastic body must not exceed the specified maximum storage temperature (t stg(max) ). if the printed-circuit board has been pre-heated, forced cooling may be necessary immediately after soldering to keep the temperature within the permissible limit. 18.3 manual soldering apply the soldering iron (24 v or less) to the lead(s) of the package, either below the seating plane or not more than 2 mm above it. if the temperature of the soldering iron bit is less than 300 ? c it may remain in contact for up to 10 seconds. if the bit temperature is between 300 ? c and 400 ? c, contact may be up to 5 seconds. msl: moisture sensitivity level fig 21. temperature profiles for large and small components 001aac844 temperature time minimum peak temperature = minimum soldering temperature maximum peak temperature = msl limit, damage level peak temperature
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 25 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt 18.4 package related soldering information [1] for sdip packages, the longitudinal axis must be para llel to the transport direction of the printed-circuit board. [2] for pmfp packages hot bar solder ing or manual soldering is suitable. table 13. suitability of through-hole mount ic packages for dipping and wave soldering package soldering method dipping wave cpga, hcpga - suitable dbs, dip, hdip, rdbs, sd ip, sil suitable suitable [1] pmfp [2] - not suitable
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 26 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt 19. soldering: pcb footprints fig 22. pcb footprint for sot162-1 (so16); reflow soldering dimensions in mm ay by d1 d2 gy hy p1 11.200 6.400 2.400 0.700 c 0.800 10.040 8.600 gx 11.450 sot162-1_fr hx 11.900 1.270 sot162-1 solder land occupied area footprint information for reflow soldering of so16 package ay by gy c hy hx gx p1 generic footprint pattern refer to the package outline drawing for actual layout p2 (0.125) (0.125) d1 d2 (4x) p2 1.320
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 27 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt fig 23. pcb footprint for sot266-1 (ssop20); reflow soldering dimensions in mm ay by d1 d2 gy hy p1 7.200 4.500 1.350 0.400 c 0.600 6.900 5.300 gx 7.450 sot266-1_fr hx 7.300 0.650 sot266-1 solder land occupied area footprint information for reflow soldering of ssop20 package p2 0.750 p2 gy c hy (0.125) ay by (0.125) hx gx p1 d1 d2 (4x)
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 28 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt 20. abbreviations table 14. abbreviations acronym description cdm charged-device model cmos complementary metal oxide semiconductor i/o input/output i 2 c-bus inter ic bus esd electrostatic discharge ff flip-flop gpio general purpose input/output hbm human body model ic integrated circuit led light emitting diode lp low-pass plc programmable logic controller por power-on reset
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 29 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt 21. revision history table 15. revision history document id release date data sheet status change notice supersedes pcf8574_pcf8574a v.5 20130527 product data sheet - pcf8574 v.4 modifications: ? the format of this data sheet has been redesigned to comply with the new identity guidelines of nxp semiconductors. ? legal texts have been adapted to the new company name where appropriate. ? electrical parameter letter-symbols and thei r definitions are updated to conform to nxp presentation standards. ? section 1 ? general description ? : updated ? section 2 ? features and benefits ? : ? third bullet item: appended ?with non-overvoltage tolerant i/o held to v dd with 100 ? a current source? ? added (new) fourth and seventh bullet items ? added sixth bullet item: ?total package sink capability of 80 ma? ? ninth bullet changed from ?(10 ? a maximum)? to ?(2.5 ? a typical)? ? deleted (old) 11th, 12th and 13th bullet items ? added (new) eighth bullet item ?mobile devices? ? table 1 ? ordering information ? : ? type number corrected from ?pcf8574t? to ?pcf8574/3? ? type number corrected from ?pcf8574at? to ?pcf8574at/3? ? type number corrected from ?pcf8574ts? to ?pcf8574ts/3? ? type number corrected from ?pcf8574ats? to ?pcf8574ats/3? ? added section 4.1 ? ordering options ? ? figure 4 ? pin configuration for so16 ? : updated type numbers (appended ?/3?) ? figure 5 ? pin configuration for ssop20 ? : updated type numbers (appended ?/3?) ? section 6.2 ? pin description ? : combined dip16, so16 and ssop20 pin descriptions into one table ( ta b l e 3 ) ? section 7 ? functional description ? reorganized ? section 7.1 ? device address ? , first paragraph, fourth senten ce: appended ?so they must be externally held high or low? ? table 4 ? pcf8574 address map ? updated: added column for 7-bit hexadecimal address without r/w ? table 5 ? pcf8574a address map ? updated: added column for 7-bit hexadecimal address without r/w ? section 8.1 ? quasi-bidirectional i/os ? : re-written and placed before section 8.4 ? power-on reset ? ? added section 8.2 ? writing to the port (output mode) ? ? added section 8.3 ? reading from a port (input mode) ? ? figure 9 ? read mode (input) ? : changed symbol ?t ps ? to ?t su ? ? section 8.4 ? power-on reset ? re-written ? section 8.5 ? interrupt output ( int ) ? re-written ? figure 10 ? application of multiple pcf8574/74as with interrupt ? updated: changed device 16 from ?pcf8574? to ?pcf8574a? ? section 9.3 ? acknowledge ? , first paragraph, thir d sentence re-written. ? added section 10 ? application design-in information ?
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 30 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt modifications: (continued) ? table 7 ? limiting values ? : ? changed parameter description for symbol i i from ?dc input current? to ?input current? ? changed parameter description for symbol i o from ?dc output current? to ?output current? ? changed parameter description for symbol i ss from ?supply current? to ?ground supply current? ? changed symbol ?p o ? to ?p/out? ? added t j(max) limits ? added section 12 ? thermal characteristics ? ? table 9 ? static characteristics ? : ? table title changed from ?dc characteristics? to ?static characteristics? ? sub-section ?i/os; p0 to p7?: chan ged parameter description for symbol i trt(pu) from ?transient pull-up current? to ?transient boosted pull-up current? ? moved sub-section ?port timing? to table 10 ? dynamic characteristics ? ? sub-section ?interrupt int ?: moved sub-sub-section ?timing? to table 10 ? dynamic characteristics ? ? table 10 ? dynamic characteristics ? : ? sub-section ?i 2 c-bus timing?: deleted symbol/parameter ?t sw , tolerable spike width on bus? ? sub-section ?port timing?: ch anged symbol/parameter from ?t pv , output data valid time? to ?t v(q) , data output valid time? ? sub-section ?port timing?: ch anged symbol/parameter from ?t su , input data set-up time? to ?t su(d) , data input set-up time? ? sub-section ?port timing?: ch anged symbol/parameter from ?t h , input data hold time? to ?t h(d) , data input hold time? ? sub-section ?interrupt int ?: changed parameter de scription for symbol t v(int) from ?int output valid time? to ?valid time on pin int ? ? sub-section ?interrupt int ?: changed parameter de scription for symbol t rst(int) from ?int reset delay time? to ?reset time on pin int ? ? added section 19 ? soldering: pcb footprints ? pcf8574 v.4 (9397 750 10462) 20021122 product specification - pcf8574 v.3 pcf8574 v.3 (9397 750 09911) 20020729 product specification - pcf8574 v.2 pcf8574 v.2 (9397 750 01758) 19970402 product specification - pcf8574_pcf8574a v.1 pcf8574_pcf8574a v.1 (9397 750 70011) 199409 product specification - - table 15. revision history ?continued document id release date data sheet status change notice supersedes
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 31 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt 22. legal information 22.1 data sheet status [1] please consult the most recently issued document before initiating or completing a design. [2] the term ?short data sheet? is explained in section ?definitions?. [3] the product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple device s. the latest product status information is available on the internet at url http://www.nxp.com . 22.2 definitions draft ? the document is a draft versi on only. the content is still under internal review and subject to formal approval, which may result in modifications or additions. nxp semiconductors does not give any representations or warranties as to the accuracy or completeness of information included herein and shall hav e no liability for the consequences of use of such information. short data sheet ? a short data sheet is an extract from a full data sheet with the same product type number(s) and title. a short data sheet is intended for quick reference only and should not be relied upon to contain detailed and full information. for detailed and full information see the relevant full data sheet, which is available on request vi a the local nxp semiconductors sales office. in case of any inconsistency or conflict with the short data sheet, the full data sheet shall prevail. product specification ? the information and data provided in a product data sheet shall define the specification of the product as agreed between nxp semiconductors and its customer , unless nxp semiconductors and customer have explicitly agreed otherwis e in writing. in no event however, shall an agreement be valid in which the nxp semiconductors product is deemed to offer functions and qualities beyond those described in the product data sheet. 22.3 disclaimers limited warranty and liability ? information in this document is believed to be accurate and reliable. however, nxp semiconductors does not give any representations or warranties, expressed or implied, as to the accuracy or completeness of such information and shall have no liability for the consequences of use of such info rmation. nxp semiconductors takes no responsibility for the content in this document if provided by an information source outside of nxp semiconductors. in no event shall nxp semiconductors be liable for any indirect, incidental, punitive, special or consequential damages (including - without limitation - lost profits, lost savings, business interruption, costs related to the removal or replacement of any products or rework charges) whether or not such damages are based on tort (including negligence), warranty, breach of contract or any other legal theory. notwithstanding any damages that customer might incur for any reason whatsoever, nxp semiconductors? aggregate and cumulative liability towards customer for the products described herein shall be limited in accordance with the terms and conditions of commercial sale of nxp semiconductors. right to make changes ? nxp semiconductors reserves the right to make changes to information published in this document, including without limitation specifications and product descriptions, at any time and without notice. this document supersedes and replaces all information supplied prior to the publication hereof. suitability for use ? nxp semiconductors products are not designed, authorized or warranted to be suitable for use in life support, life-critical or safety-critical systems or equipment, nor in applications where failure or malfunction of an nxp semiconductors product can reasonably be expected to result in personal injury, death or severe property or environmental damage. nxp semiconductors and its suppliers accept no liability for inclusion and/or use of nxp semiconducto rs products in such equipment or applications and therefore such inclusion and/or use is at the customer?s own risk. applications ? applications that are described herein for any of these products are for illustrative purpos es only. nxp semiconductors makes no representation or warranty that such applications will be suitable for the specified use without further testing or modification. customers are responsible for the design and operation of their applications and products using nxp semiconductors products, and nxp semiconductors accepts no liability for any assistance with applications or customer product design. it is customer?s sole responsibility to determine whether the nxp semiconductors product is suitable and fit for the customer?s applications and products planned, as well as fo r the planned application and use of customer?s third party customer(s). customers should provide appropriate design and operating safeguards to minimize the risks associated with their applications and products. nxp semiconductors does not accept any liability related to any default, damage, costs or problem which is based on any weakness or default in the customer?s applications or products, or the application or use by customer?s third party customer(s). customer is responsible for doing all necessary testing for the customer?s applic ations and products using nxp semiconductors products in order to av oid a default of the applications and the products or of the application or use by customer?s third party customer(s). nxp does not accept any liability in this respect. limiting values ? stress above one or more limiting values (as defined in the absolute maximum ratings system of iec 60134) will cause permanent damage to the device. limiting values are stress ratings only and (proper) operation of the device at these or any other conditions above those given in the recommended operating conditions section (if present) or the characteristics sections of this document is not warranted. constant or repeated exposure to limiting values will permanently and irreversibly affect the quality and reliability of the device. terms and conditions of commercial sale ? nxp semiconductors products are sold subject to the gener al terms and conditions of commercial sale, as published at http://www.nxp.com/profile/terms , unless otherwise agreed in a valid written individual agreement. in case an individual agreement is concluded only the terms and conditions of the respective agreement shall apply. nxp semiconductors hereby expressly objects to applying the customer?s general terms and conditions with regard to the purchase of nxp semiconducto rs products by customer. no offer to sell or license ? nothing in this document may be interpreted or construed as an offer to sell products t hat is open for acceptance or the grant, conveyance or implication of any lic ense under any copyrights, patents or other industrial or intellectual property rights. document status [1] [2] product status [3] definition objective [short] data sheet development this document contains data from the objecti ve specification for product development. preliminary [short] data sheet qualification this document contains data from the preliminary specification. product [short] data sheet production this document contains the product specification.
pcf8574_pcf8574a all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 5 ? 27 may 2013 32 of 33 nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt export control ? this document as well as the item(s) described herein may be subject to export control regu lations. export might require a prior authorization from competent authorities. non-automotive qualified products ? unless this data sheet expressly states that this specific nxp semicon ductors product is automotive qualified, the product is not suitable for automotive use. it is neither qualified nor tested in accordance with automotive testing or application requirements. nxp semiconductors accepts no liabili ty for inclusion and/or use of non-automotive qualified products in automotive equipment or applications. in the event that customer uses t he product for design-in and use in automotive applications to automotive specifications and standards, customer (a) shall use the product without nxp semiconductors? warranty of the product for such automotive applicat ions, use and specifications, and (b) whenever customer uses the product for automotive applications beyond nxp semiconductors? specifications such use shall be solely at customer?s own risk, and (c) customer fully indemnifies nxp semiconductors for any liability, damages or failed product claims resulting from customer design and use of the product for automotive app lications beyond nxp semiconductors? standard warranty and nxp semiconduct ors? product specifications. translations ? a non-english (translated) version of a document is for reference only. the english version shall prevail in case of any discrepancy between the translated and english versions. 22.4 trademarks notice: all referenced brands, produc t names, service names and trademarks are the property of their respective owners. i 2 c-bus ? logo is a trademark of nxp b.v. 23. contact information for more information, please visit: http://www.nxp.com for sales office addresses, please send an email to: salesaddresses@nxp.com
nxp semiconductors pcf8574; pcf8574a remote 8-bit i/o expander for i 2 c-bus with interrupt ? nxp b.v. 2013. all rights reserved. for more information, please visit: http://www.nxp.com for sales office addresses, please se nd an email to: salesaddresses@nxp.com date of release: 27 may 2013 document identifier: pcf8574_pcf8574a please be aware that important notices concerning this document and the product(s) described herein, have been included in section ?legal information?. 24. contents 1 general description . . . . . . . . . . . . . . . . . . . . . . 1 2 features and benefits . . . . . . . . . . . . . . . . . . . . 1 3 applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 4 ordering information . . . . . . . . . . . . . . . . . . . . . 2 4.1 ordering options . . . . . . . . . . . . . . . . . . . . . . . . 2 5 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 3 6 pinning information . . . . . . . . . . . . . . . . . . . . . . 4 6.1 pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 6.2 pin description . . . . . . . . . . . . . . . . . . . . . . . . . 4 7 functional description . . . . . . . . . . . . . . . . . . . 5 7.1 device address . . . . . . . . . . . . . . . . . . . . . . . . . 5 7.1.1 address maps. . . . . . . . . . . . . . . . . . . . . . . . . . 5 8 i/o programming . . . . . . . . . . . . . . . . . . . . . . . . 6 8.1 quasi-bidirectional i/os . . . . . . . . . . . . . . . . . . 6 8.2 writing to the port (output mode) . . . . . . . . . . . 8 8.3 reading from a port (input mode) . . . . . . . . . . 9 8.4 power-on reset . . . . . . . . . . . . . . . . . . . . . . . . . 9 8.5 interrupt output (int ) . . . . . . . . . . . . . . . . . . . 10 9 characteristics of the i 2 c-bus . . . . . . . . . . . . 11 9.1 bit transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 9.1.1 start and stop conditions . . . . . . . . . . . . . 11 9.2 system configuration . . . . . . . . . . . . . . . . . . . 11 9.3 acknowledge . . . . . . . . . . . . . . . . . . . . . . . . . 12 10 application design-in information . . . . . . . . . 13 10.1 bidirectional i/o expander applications . . . . . 13 10.2 how to read and write to i/o expander (example) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 10.3 high current-drive load applications . . . . . . . . 14 10.4 migration path . . . . . . . . . . . . . . . . . . . . . . . . . 14 11 limiting values. . . . . . . . . . . . . . . . . . . . . . . . . 15 12 thermal characteristics . . . . . . . . . . . . . . . . . 15 13 static characteristics. . . . . . . . . . . . . . . . . . . . 16 14 dynamic characteristics . . . . . . . . . . . . . . . . . 17 15 package outline . . . . . . . . . . . . . . . . . . . . . . . . 19 16 handling information. . . . . . . . . . . . . . . . . . . . 22 17 soldering of smd packages . . . . . . . . . . . . . . 22 17.1 introduction to soldering . . . . . . . . . . . . . . . . . 22 17.2 wave and reflow soldering . . . . . . . . . . . . . . . 22 17.3 wave soldering . . . . . . . . . . . . . . . . . . . . . . . . 22 17.4 reflow soldering . . . . . . . . . . . . . . . . . . . . . . . 23 18 soldering of through-hole mount packages . 24 18.1 introduction to soldering through-hole mount packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 18.2 soldering by dipping or by solder wave . . . . . 24 18.3 manual soldering . . . . . . . . . . . . . . . . . . . . . . 24 18.4 package related solderi ng information. . . . . . 25 19 soldering: pcb footprints . . . . . . . . . . . . . . . 26 20 abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . 28 21 revision history . . . . . . . . . . . . . . . . . . . . . . . 29 22 legal information . . . . . . . . . . . . . . . . . . . . . . 31 22.1 data sheet status . . . . . . . . . . . . . . . . . . . . . . 31 22.2 definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 22.3 disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . . 31 22.4 trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . 32 23 contact information . . . . . . . . . . . . . . . . . . . . 32 24 contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33