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F75385M ? 1 o c accuracy temperature sensor ic datasheet release date: july, 2006 revision: v0.21p
f75385 f75385 july, 2006 -i- f75385 datasheet revision history version date page revision history 0.20p march, 2006 - original release version 0.21p july, 2006 10 modify vt1/vt2 high limit and vt1 therm limit default value. original (64h) ? new (55h) please note that all data and specifications are subject to change without notice. all t he trade marks of products and companies mentioned in this data sheet belong to their respective owners. life support applications these products are not designed for use in life support applia nces, devices, or systems where malfunction of these products can reasonably be expected to result in personal injury. customers using or selling these products for use in such applications do so at their own risk and agr ee to fully indemnify fintek for any damages resulting from such improper use or sales.
f75385 f75385 july, 2006 -ii- table of contents 1. general description ................................................................................................................. 1 2. features ............................................................................................................................... ... 1 3. key specifications ................................................................................................................... 2 4. pin configuration ..................................................................................................................... 2 5. pin descriptions ...................................................................................................................... 2 6. functional description ............................................................................................................. 3 6.1 general descrip tion....................................................................................................... ... 3 6.2 the warn ing mess age ...................................................................................................... 3 6.3 access interface.......................................................................................................... ..... 3 6.4 temperature m onitori ng ..................................................................................................... 4 6.5 al ert#.................................................................................................................... ............ 5 6.5 therm# ......................................................................................................................... ... 5 6.6 adc conversion sequence ............................................................................................... 6 6.7 thermal mass and se lf heating......................................................................................... 6 6.8 adc noise f ilterin g ........................................................................................................... 6 6.9 pcb layout guide ............................................................................................................. 6 7. registers description .............................................................................................................. 8 7.1 configuration register ? index 03h(read), 09h(writ e)................................................... 8 7.2 status register ? index 02h .............................................................................................. 8 7.3 conversion rate register ? index 04h(read), 0ah(write)................................................ 8 7.4 one-shot register ? index 0fh......................................................................................... 9 7.5 alert queue & timeout register ? index 22h .................................................................... 9 7.6 status-with-ara control register ? index 24h ............................................................... 9 7.7 chip id i register ? index 5ah........................................................................................ 10 7.8 chip id ii register ? index 5bh....................................................................................... 10 7.9 vendor id i (manufacturer id) register ? index 5dh....................................................... 10 7.10 vendor id i (manufa cturer id) register ? index 5eh ..................................................... 10 7.11 vendor id ii (manu facturer id) register ? index feh .................................................... 10 7.12 value ram ? index 10h- 2fh ........................................................................................ 10 8. electrical c haracteri stic...................................................................................................... .... 12 8.1 absolute ma ximum ra tings .............................................................................................. 12 8.2 dc charac teristics ......................................................................................................... ... 12 8.3 ac charac teristics ......................................................................................................... ... 13 9. ordering in formati on ........................................................................................................... .. 13 10. package dimensions (8 msop)............................................................................................ 14
july 2006 v0.21p -1- 1. general description the f75385 is a temperature sensor ic with alert si gnal which is specific designed for notebook, graphic cards etc. an 11-bit analog-to-digital converter (adc) was built inside f75385. the f75385 can monitor two set of temperature which is very important for the system to work stably and properly. this chip provides 1 remote temperature sensor and 1 local temperature sensor. the remote temperature sensor can be performed by cpu thermal diode or transistor 2n3906. the users can set up the upper and lower limits (alarm thresholds) of all monitored parameters and this chip can also issue warning messages for system protection when there is something wrong with monitored items. through the bios or application software, the users c an read all the monitored parameters of system all the time. and a pop-up warning can be also acti vated when the monitored item was out of the proper/pre-setting range. the application software could be fintek's application utilit y, or other management application software. the f75385 is in the pa ckage of 8-pin msop and powered by 3.3v. 2. features ? provide 1 on-chip local and 1 remote temperature sensing ? ? 1 o c accuarcy on remote channel and ? 3 o c accuarcy on local channel ? ? 1 o c ( + 60 o c to +100 o c, remote) ? ? 3 o c ( + 60 o c to +100 o c, local) ? alert# output for smbus alert ? therm# output for over temperature alert or for system shut down ? programmable therm# limits and therm# hysteresis ? programmable alert queue ? programmable limited and setting points(ale rt threshold) for all monitored items ? 2 wire smbus interface ? 3vcc operation and in 8-msop package ? the smbus slave address: a6 a5 a4 a3 a2 a1 a0 f75385 1 0 0 1 1 0 0 --patented: tw 235231--
july 2006 v0.21p -2- 3. key specifications ? supply voltage 3.0~3.6v ? supply current 180 ua (typ) ? measured range 0 ~ 145 o c ? remote diode temperature accuracy 1 o c from +60 o c to +100 o c ? local temperature accuracy 3 o c from +60 o c to +100 o c 4. pin configuration gnd vcc sda d+ alert# scl d- therm# 1 2 3 45 6 7 8 f75382 5. pin descriptions od 12 - open-drain output pin with 12 ma sink capability pwr - power pin in ts - ttl level input pin and schmitt trigger ain - input pin(analog) pin no pin name type pwr description 1 vcc pwr 3vcc power pin 2 d+ ain 3vcc positive connection to remote tem perature sensor (ex: thermal diode anode) 3 d- ain 3vcc negative connection to remote te mperature sensor(ex: thermal diode cathode) 4 therm# od 12 3vcc active low output. this pin will be logic low when the temperature exceeds its limit. (default 108 o c enable) 5 gnd pwr 3vcc ground 6 alert# od 12 3vcc active low output. used as smbus alert or interrupt 7 sda in ts /od 12 3vcc serial bus data 8 scl in ts 3vcc serial bus clock F75385M
july 2006 v0.21p -3- 6. functional description 6.1 general description the f75385 is a simple temperature sensor with warning signal output. it includes a local and a remote temperature sensor. both measured temperature are compar ed with its high, low and therm limits which are stored in the registers. when one or more out -of-limit events occur, the flags in st atus register will be set and that may cause alert output to low. also, measured temperature e xceeding therm limit may cause therm output to low. 6.2 the warning message pin4 and pin6 act as warning message when the temperature exceeds it threshold point. 6.3 access interface the f75385 can be connected to a compatible 2-wire serial system management bus as a slave device under the control of the master devic e, using two device terminals scl and sda. the f75385 supports smbus protocol of, ?write byte?, ?read byte?, both with or without packe t error checking(pec) which is calculated using crc-8. for detail information about pec, please check smbus 1.1 specific ation. f75385 supports 25ms timeout for no activity on the smbus. this timeout function is programmed at 22h bi t7 and default is disabled. f75385 also supports alert response address (ara) protocol. the operation of the protocol is described with details in the following sections. (a) smbus write to internal address re gister followed by the data byte 0 start by master 0 1 011 00 d7 d6 d5 d4 d3 d2 d1 d0 ack by 382 r/w ack by 382 scl sda d7 d6 d5 d4 d3 d2 d1 d0 stop by master scl sda (continued) 780 78 0 78 frame 2 internal index register byte (continued) frame 3 data byte frame 1 serial bus address byte figure 1. serial bus write to internal address register followed by the data byte
july 2006 v0.21p -4- (b) serial bus write to internal address register only 0 start by master 0 1 011 00 d7 d6 d5 d4 d3 d2 d1 d0 ack by 382 r/w ack by 382 scl sda 780 78 0 frame 2 internal index register byte frame 1 serial bus address byte figure 2. serial bus write to internal address register only stop by master (c) serial bus read from a register with the internal address register prefer to desired location 0 start by master 0 1011 00 d7 d6 d5 d4 d3 d2 d1 d0 ack by master r/w ack by 382 scl sda 780 78 0 frame 2 internal index register byte frame 1 serial bus address byte figure 3. serial bus read from internal address register stop by master (d) alert response address 0 start by master 00011 00 01001100 ack by master r/w ack by 382 scl sda 780 78 0 frame 2 device address frame 1 alert response address figure 4. alert response address stop by master 6.4 temperature monitoring the f75385 monitors a local and a remote temperature sensor. both can be measured from 0c to 145c. the temperature format is as the following table: temperature ( high byte ) digital output temperature ( low byte ) digital output 0c 0000 0000 0c 000 0 0000 1c 0000 0001 0.125c 001 0 0000 25c 0001 1001 0.250c 010 0 0000 50c 0011 0010 0.375c 011 0 0000 75c 0100 1011 0.500c 100 0 0000 90c 0101 1010 0.625c 101 0 0000
july 2006 v0.21p -5- 100c 0110 0100 0.750c 110 0 0000 145c 1001 0001 0.875c 111 0 0000 remote-sensor transistor manufacturers manufacturer model number panasonic 2sb0709 2n3906 philips pmbt3906 6.5 alert# five events can trigger alert# to low: (1). vt1(local) temperature exceeds high limit (2). vt1(local) temperature goes below low limit (3). vt2(remote) temperature exceeds high limit (4). vt2(remote) temperature goes below low limit (5). vt2(remote) temperature is open-circuit. these five events are wired-nor together. this means that when one of out-of-limit event occurs, the alert# output goes low if the mask control is disabled. alert# signal can be used as an irq-like interrupt or as an smbalert. when alert# acts as an irq-like interrupt, the alert# will be de-asserted until the following 2 conditions are matched: (1). the abnormal condition is gone (2). reading the status register to clear the status when alert# acts as a smbalert, the alert# will be de-asserted until the following 3 conditions are matched: (1). the abnormal condition is gone (2). reading the status register to clear the status (3). the alert# has been serviced by the smbus master reading the device address. for more information about smbalert, please see smbus 1.1 specification. 6.6 therm# either vt1(local) or vt2(remote) temperature exceeds the corresponding therm limit, the therm# output will assert low. the asserted output will be de-asserted unt il the temperature goes below (therm limit ? hysteresis). the hysteresis default value is 10c and it can be programmed. both vt1 and vt2 have their own therm limits and
july 2006 v0.21p -6- hysteresis values. 6.7 adc conversion sequence if a start command is written, both channels are conver ted and the results of both measurements are available after the end of conversion. a busy stat us bit in the status byte shows that the device is actually performing a new conversion; however, even if the adc is busy, the results of the previous conversion are always available. 6.8 thermal mass and self heating thermal mass effect can seriously degrade effective accura cy of the f75385. the ther mal time constant of the sop package is about 140 in still air. fo r the f75385 junction temperature to settle to within +1c after a sudden +100c change requires about five time constants or 12 minutes. the use of smaller packages for remote sensors such as sot23, improves the situation. take care to a ccount for thermal gradients bet ween the heat source and the sensor package do not interfere with measurement accuracy . sel-heating does not significantly affect measurement accuracy. remote sensor self-heating due to the diode curren t source is negligible. for the local diode, the worst case error occurs when auto-converting at the fastest rate and simultaneously sinking maximum current at the alert# output. for instance, at an 64hz rate and alert# sink ar ound 0.7ma when pull up resistor 4.7k ohm to 3.3vcc, the typical power dissipation is vcc x 22 0 ua plus 0.4v x 0.7ma. package ja is about 120 c/w, so with vcc = 3.3v and no copper pc board heat-sinking, the resulting temperature rise is: dt = 1.01mw x 120 c/w = 0.12 c even with these contrived circumstances, it is diff icult to introduce significant self-heating errors. 6.9 adc noise filtering the adc is integrating type with inherently good noise re jection. micro-power operation places constraints on high-frequency noise rejection; therefore, careful pcb boar d layout and suitable external filtering are required for high-accuracy remote measurement in electronically noisy environment. high frequency emi is best filtered at d+ and d- with an external 2200pf capacitor. too high capacitance may introduce errors due to the rise time of the switched current source. nearly all noise source s tested cause the adc measurement to be higher than the actual temperature, depending on the frequency and amplitude. 6.10 pcb layout guide pcb can be electrically noisy environments, and the f753 85 is measuring very small voltage from the remote sensor, so care must be taken to minimize noise which is occurred at the sensor inputs. the following guideline should be taken to reduce the measurem ent error of the temperature sensors:
july 2006 v0.21p -7- 1. place the f75385 as close as practical to the remote s ensing diode. in noisy environments, such as a computer main-board, the distance can be 4 to 8 inches. (typ). this length can be increased if the worst noise sources are avoided. noise sources generally include clock generator s, power control circuit, crts, memory buses and pci/isa bus etc. 2. route the d+ and d- tracks close t ogether, in parallel, with grounded guard tracks on each side. provide a ground plane under the tracks if possible. do not route d+ & d- lin es next to the deflection coil of the crt. and also don?t route the trace across fast digital signal s which can easily induce bigger error. gnd gnd dxp 10mils 10mils minimum 10mils dxn 10mils 3. use wide tracks to minimize inductance and reduce noise pickup. 10 mil track minimum width and spacing is recommended. 4. try to minimize the number of copper/solder joints, wh ich can cause thermocouple effects. where copper/solder joints are used, make sure that they are in both the d+ and d- path and at the same temperature. thermocouple effects should not be a major problem as 1 corresponds to about 200v j . it means that a copper-solder thermocouple exhibits 3v/ j , and takes about 200v of the voltage error at d+ & d- to cause a 1 j measurement error. adding a few thermocouples causes a negligible error. 5. place a 0.1f bypass capacitor close to the v dd pin. in very noisy environments, place an external 2200pf input filter capacitors across d+, d- close to the f75385. 6. if the distance to the remote sensor is more than 8 inch es, the use of twisted pair cable is recommended. it will work up to around 6 to 12 feet. 7. because the measurement technique uses switched current sources, excessive cable and/or filter capacitance will affect the measurement accuracy. when using long cables, the filter capacitor may be reduced or removed. cable resistance can also induce errors. 1 ? series resistance introduces about 0.5 er j ror.
july 2006 v0.21p -8- 7. registers description 7.1 configuration register ? index 03h(read), 09h(write) power on default <7:0> = 00h bit name attribute description 7 alert_mask r/w set to 1, mask alert# signal output. 6 run_stop r/w set to 0, monitor. set to 1, stop to monitor(software power down). 5-0 reserved 7.2 status register ? index 02h power on default <7:0> = 00h bit name attribute description 7 adc_busy ro set to 1, adc is converting. 6 vt1high ro set to 1, vt1 temperature exceeds high limit. set to 0, vt1 temperature does not exceed high limit. 5 vt1low ro set to 1, vt1 temperature goes below low limit. set to 0, vt1 temperature does not goes below low limit. 4 vt2high ro set to 1, vt2 temperature exceeds high limit. set to 0, vt2 temperature does not exceed high limit. 3 vt2low ro set to 1, vt2 temperature goes below low limit. set to 0, vt2 temperature does not goes below low limit. 2 open ro set to 1, vt2 is open-circuit. 1 vt2therm ro set to 1, vt2 tem perature exceeds its therm limit. 0 vt1therm ro set to 1, vt1 temperature exceeds its therm limit. vt1(local) ; vt2(remote ) 7.3 conversion rate register ? index 04h(read), 0ah(write) power on default <7:0> = 08h bit name attribute description set conversion times per second. 7-0 conv_rate r/w value conversion/sec value conversion/sec
july 2006 v0.21p -9- 00h 0.0625 06h 4 01h 0.125 07h 8 02h 0.25 08h 16 03h 0.5 09h 32 04h 1 0ah 64 05h 2 0bh ~ ffh reserved 7.4 one-shot register ? index 0fh power on default <7:0> = xxh bit name attribute description 7-0 one-shot wo when f75385 is at standby mode, writing any value to this register will initiate a single conversion and compar ison cycle. after the single cycle, f75385 will returns to standby mode. 7.5 alert queue & timeout register ? index 22h power on default <7:0> = 01h bit name attribute description 7 en_i2ctmout r/w set to 1, enable serial inte rface timeout function. (timeout time = 25ms) set to 0, disable. 6-4 reserved 3-1 alert_queue r/w this number determines how many abnormal measurements must occur before alert signal is generated. 000 : once 001 : twice 011 : 3 times 111 : 4 times 0 reserved ro always read 1. 7.6 status-with-ara control register ? index 24h power on default <7:0> = 01h bit name attribute description 7-6 reserved
july 2006 v0.21p -10- 0 en_ara_sts r/w set to 1, alert de-asserted condition is related with ara. set to 0, alert de-asserted condition is not related with ara(alert response address). 7.7 chip id i register ? index 5ah power on default: 03h. 7.8 chip id ii register ? index 5bh power on default: 03h. 7.9 vendor id i (manufacturer id) register ? index 5dh power on default: 19h. 7.10 vendor id i (manufacturer id) register ? index 5eh power on default: 34h. 7.11 vendor id ii (manufacturer id) register ? index feh power on default: 23h. (programmable) 7.12 value ram ? index 10h- 2fh vt1 : local temperature vt2 : remote temperature the value in quota is its power-on default value . description attribute read address (high byte) read address (low byte) write address (high byte) write address (low byte) vt1 reading ro 00h 1ah vt2 reading ro 01h 10h vt1 high limit r/w 05h (55h) 1bh (00h) 0bh 1bh vt1 low limit r/w 06h (00h) 1ch (00h) 0ch 1ch vt2 high limit r/w 07h (55h) 13h (00h) 0dh 13h
july 2006 v0.21p -11- vt2 low limit r/w 08h (00h) 14h (00h) 0eh 14h vt1 therm limit r/w 20h (55h) 20h vt1 therm hysteresis r/w 21h (0ah) 21h vt2 therm limit r/w 19h (6ch) 19h vt2 therm hysteresis r/w 23h (0ah) 23h
july 2006 v0.21p -12- 8. electrical characteristic 8.1 absolute maximum ratings parameter rating unit power supply voltage -0.5 to 3.3 v input voltage -0.5 to vdd+0.5 v operating temperature 0 to +140 c storage temperature -55 to 150 c note: exposure to conditions beyond those listed under absolute maximum ratings may adversely affect the life and reliability o f the device 8.2 dc characteristics (t a = 0 c to 70 c, vdd = 3.3v 10%, vss = 0v ) parameter conditions min typ max unit temperature error, remote diode 60 o c < t d < 100 o c, vcc = 3.0v to 3.6v 0 o c july 2006 v0.21p -13- input low threshold voltage vt- 0.5 0.8 1.1 v vdd = 3.3v input high threshold voltage vt+ 1.6 2.0 2.4 v vdd = 3.3v input high leakage ilih +1 a vin = vdd input low leakage ilil -1 a vin = 0 v 8.3 ac characteristics valid data scl sda in sda out t hd;sda t scl t t su;sto t su;dat serial bus timing diagram t r t r hd;dat serial bus timing parameter symbol min. max. unit scl clock period t - scl 10 us start condition hold time t hd;sda 4.7 us stop condition setup-up time t su;sto 4.7 us data to scl setup time t su;dat 120 ns data to scl hold time t hd;dat 5 ns scl and sda rise time t r 1.0 us scl and sda fall time t f 300 ns 9. ordering information part number package type production flow F75385M 8 pin msop (green package) commercial, 0 c to +70 c

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