mitsumi system reset (with built-in watchdog timer) mm1035 system reset (with built-in watchdog timer) monolithic ic mm1035 outline this ic functions in a variety of cpu systems and other logic systems to generate a reset signal and reset the system accurately during momentary interruption or lowering of power supply voltage. it also has a built-in watchdog timer for operation diagnosis. this prevents the system from running wild by generating an intermittent reset pulse during system mis-operation. features 1. built-in watchdog timer 2. low minimum operating voltage v cc =0.8v typ. 3. both positive and negative logic reset output can be extracted 4. accurate detection of drop in power supply voltage 5. detection voltage has hysteresis 6. few external parts 1 capacitor package dip-8a (mm1035xd) sop-8a (MM1035XF) applications microcomputers absolute maximum ratings (ta=25 c) item symbol rating units storage temperature t stg - 40~+125 c operating temperature t opr - 20~+70 c power supply voltage v cc max. - 0.3~+10 v voltage applied to vs & ck pins v vs & v ck - 0.3~+10 v voltage applied to reset, reset pin v oh - 0.3~+10 v allowable loss pd 400 mw
mitsumi system reset (with built-in watchdog timer) mm1035 electrical characteristics 1 (dc) (except where noted otherwise, ta=25c, v cc =5v, measurement circuit 1) item symbol measurement measurement conditions min. typ. max. units circuit consumption current i cc 1 during watchdog timer operation 0.7 1.0 ma detection voltage v sl 1 4.05 4.20 4.35 v v sh 1 4.15 4.30 4.45 detection voltage v s / t 1 0.01 %/ c temperature coefficient hysteresis voltage v hys 1 50 100 150 mv ck input threshold v th 1 0.8 1.2 2 v ck input current i ih 1v ck =5v 0 1 a i il 1v ck =0v - 20 - 10 - 3 output voltage (high) v oh 11 i= - 5a, v s =open 4.5 4.8 v v oh 21 i reset = - 5a, v s =0v 4.5 4.8 v ol 1 1 i =3ma, v s =0v 0.2 0.4 output voltage (low) v ol 2 1 i =10ma, v s =0v 0.3 0.5 v v ol 31 i reset =0.5ma, v s =open 0.2 0.4 v ol 41 i reset =1ma, v s =open 0.3 0.5 output sink current i ol 1 1 v =1.0v, v s =0v 10 16 ma i ol 21 v reset =1.0v, v s =open 1 2 i ct 11 v tc = 1.0v during watchdog - 8 - 12 - 24 a c t charge current timer operation i ct 21 v tv = 1.0v during power - 0.8 - 1.2 - 2.4 a on reset operation minimum operating power v ccl 1 1 0.8 1.0 v supply voltage to ensure reset ------------------------------------------------ minimum operating power v ccl 21 i reset =v cc - 0.1v 0.8 1.0 v supply voltage to ensure reset ------------------------------------------------ r l 2 (between pin 2 and gnd) =1m reset ------------------------------------------- reset ----------------------------------------- reset ----------------------------------------- reset ----------------------------------------- v s =open, v cc v s =open, v cc v =0.4v i =0.2ma reset ------------------------------------------------ reset -------------------------------------------- v sh - v sl , v cc
mitsumi system reset (with built-in watchdog timer) mm1035 electrical characteristics 2 (ac) (except where noted otherwise, ta=25c, v cc =5v, measurement circuit 2) item symbol measurement measurement conditions min. typ. max. units circuit v cc input pulse width t pi 28s ck input pulse width t ckw 23s ck input cycle t ck 220s watchdog timer t wd 2c t =0.1f 5 10 15 ms monitoring time * 1 reset time for t wr 2c t =0.1f 1 2 3 ms watchdog timer * 2 reset hold time for t pr 2 50 100 150 ms power supply rise * 3 t pd 12 reset --------------------------------------- pin 210 output delay time from v cc r l 1=2.2k , c l 1=100pf s * 4 t pd 22 reset pin 310 r l 2=10k , c l 2=20pf t r 12 reset ---------------------------------------- pin 1.0 1.5 output rise time r l 1=2.2k , c l 1=100pf s * 5 t r 22 reset pin 1.0 1.5 s r l 2=10k , c l 2=20pf v cc 5v 4v ck or c t =0.1f, v cc notes : * 1: monitoring time is the time from the last pulse (negative edge) of the timer clear clock pulse, until reset pulse output. in other words, reset output is output if a clock pulse is not input during this time. * 2: reset time means reset pulse width. however, this does not apply to power on reset. * 3: reset hold time is the time from when v cc exceeds detection voltage (v sh ) during power on reset, until reset --------------------------------------- output goes high (reset release). * 4: output delay time is the time from when power supply voltage drops below detection voltage (v sl ), until reset --------------------------------------- output goes low (reset status). * 5: voltage range when measuring output rise and fall is 10~90%. * 6: watchdog timer monitoring time (t wd ), watchdog timer reset time (t wr ) and reset hold time (t pr ) during power supply rise can be changed by varying c t capacitance. the times are expressed by the following formulae. the recommended range for c t is 0.001~10f. t pr (ms) . = . 1000 c t (f) example : when c t =0.1f t wd (ms) . = . 100 c t (f) t pr . = . 100ms t wr (ms) . = . 20 c t (f) t wd . = . 10ms t wr . = . 2ms
mitsumi system reset (with built-in watchdog timer) mm1035 block diagram note 1: cp = 0.1f approx. note 2: c 1000pf. note 3: the watchdog timer can be stopped by connecting the rct pin to gnd. (then it functions as a voltage detection circuit.) timing chart v cc ck c t reset reset v sh v sl t ck t pr t wd t wr pin assignment 14 3 2 85 6 7 1 t c 2 reset 3 ck 4 gnd 5 v cc 6 rct 7 v s 8 reset ----------------------------------------- ~ -
mitsumi system reset (with built-in watchdog timer) mm1035 pin description pin no. pin name function 1 t c t wd , t wr , t pr variable pins. (t wd , t wr and t pr times are determined by the external capacitor.) 2 reset reset output pin (high output) 3 ck clock input pin (inputs clock from logic system) 4 gnd reset output pin (high output) 5 v cc 4.2v detection voltage 6 rct watchdog timer stop pin operation modes: operation open, stop connect to gnd 7 vs detection voltage variable pin variation modes : lower pull up resistance, raise pull down 8 reset --------------------------------------------------------------- reset output pin (low output) measuring circuit measuring circuit 1 (dc) measuring circuit 2 (ac)
mitsumi system reset (with built-in watchdog timer) mm1035 measuring circuit 1 sw table 6-1-2. sw&power supply table 1 item symbol sw1 sw2 sw3 sw4 sw5 sw6 sw7 v cc v ck v ct ii reset vm, im notes consumption current i cc off off off on b b on 5v 5v 0v -- i cc detection voltage v sl off off on on b b on 5v 0v 3v 3v -- v o 1, crt1 v sh off off on on b b on 4v 5v 3v 3v -- v o 1, crt1 ck input threshold v th off off off on b b on 5v 0v 3v 1v -- i ck ck input current i ih off off off on b b on 5v 5v 0v -- i ck i il off off off on b b on 5v 0v 0v -- i ck output voltage (high) v oh 1 on off on on b b on 5v 5v 3v - 5a - v o 1 v oh 2 off on on on c b on 5v 5v 3v -- 5a v o 2 v ol 1 onononon b b on 5v 5v 3v 3ma - v o 1 output voltage (low) v ol 2 on on on on b b on 5v 5v 3v 10ma - v o 1 v ol 3 off off on on c b on 5v 5v 3v - 0.5ma v o 2 v ol 4 off off on on c b on 5v 5v 3v - 1ma v o 2 output sink current i ol 1 off on on on b c on 5v 5v 3v -- i o 1 v oo =1v i ol 2 off off on on b a on 5v 5v 3v -- i o 2 v oo =1v c t charge current 1 i tc 1 off off off on b b off 5v - 1v -- i tc c t charge current 2 i tc 2 off off on on b b off 5v - 1v -- i tc minimum operating power supply voltage to ensure reset v ccl 1 on off on on b b on 0v 2v 0v 0v - v o 1, v cc minimum operating power supply voltage to ensure reset v ccl 2 off on on on a b on 0v 2v 0v 0v -- v o 2, v cc reset ---------------------------------------- measuring circuit 2 sw table 6-2-2. sw&power supply table 2 item symbol sw1 sw2 v cca v cc v cka v ck crt notes v cc input pulse width t pi cb -- crt1,2,3 t1=8s ck input pulse width t ckw ab 5v - crt1,2,3 t2=3s ck input cycle t ck ab 5v - crt1,2,3 t3=20s watchdog timer monitoring time t wd a a 5v 5v crt1,2,3 reset time for watchdog timer t wr a a 5v 5v crt1,2,3 reset hold time for power supply rise t pr b a a 5v 5v crt1,2,3 t pd 1c a - 0v crt1,3 output delay time from v cc t pd 2c a - 0v crt2,3 output rise time t r 1 a a 5v 5v crt1 t r 2 a a 5v 5v crt2 output fall time t p 1 a a 5v 5v crt1 t p 2 a a 5v 5v crt2 5v 4v t1 1.4v 0v t2 t3 1.4v 0v t2 t2 or 5v 0v 5v 0v 1.4v 0v t2 t3
mitsumi system reset (with built-in watchdog timer) mm1035 detection voltage variation 1 (lowering detection voltage) detection voltage can be changed by connecting resistor r1 externally to mm1035 vs pin. determine r1 according to graph 1 when changing vs. vs pin external resistance (r1) (k ) 4.0 3.5 3.0 100 200 300 400 500 600 v sh value v sl value detection voltage (vs) (v) graph 1. detection voltage change using mm1035 external resistor detection voltage variation 2 (raising detection voltage) detection voltage can be changed by connecting resistor r2 externally to mm1035 vs pin. determine r2 according to graph 2 when changing vs. 5.0 4.5 100 200 300 400 500 600 detection voltage (vs) (v) vs pin external resistance (r1) (k ) v sh value v sl value graph 2. detection voltage change using mm1035 external resistor
mitsumi system reset (with built-in watchdog timer) mm1035 characteristics power supply current-power supply voltage clock pulse input time 1.4 1.2 1.0 0.8 0.6 0.4 0.2 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 power supply current icc (ma) power supply voltage v cc (v) output voltage-power supply voltage (reset pin) 7.0 6.0 5.0 4.0 3.0 2.0 1.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 ta=20 c.25 c.75 c pull up resistance 10k power supply current icc (ma) power supply voltage v cc (v) output voltage-power supply voltage (reset ------------------------------------------------------------------ pin) ta= - 25 c ta=25 c ta=75 c 7.0 6.0 5.0 4.0 3.0 2.0 1.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 pull up resistance 2.2k output voltage v reset (v) power supply voltage v cc (v) detection voltage (v sl , v sh ) temperature (reset, reset --------------------------------------------------------------------------- pins) 4.50 4.40 4.30 4.20 4.10 4.00 3.00 - 40 - 20 0 20 40 60 80 100 ambient temperature ta ( c) v sh v sl detection voltage (v) output saturation voltage-output sink current (reset ---------------------------------------------------------------- pin) ta=75 c ta=25 c ta= - 25 c 500 400 300 200 100 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 output saturation voltage v ol (mv) output sink current i ol (ma) output saturation voltage-output sink current (reset ------------------------------------------------------------------------------ pin) 500 400 300 200 100 2 4 6 8 10 12 14 16 18 ta=75 c ta=25 c ta= - 25 c output saturation voltage v ol (mv) output sink current i ol (ma)
mitsumi system reset (with built-in watchdog timer) mm1035 high level output voltage-high level output current (reset pin) 5.0 4.8 4.6 4.4 4.2 4.0 3.8 - 2 - 4 - 6 - 8 - 10 - 12 - 14 - 16 - 18 high level output voltage v om (v) high level output current i om ( a) high level output voltage - high level output current (reset ------------------------------------------------ pin) 5.0 4.8 4.6 4.4 4.2 4.0 3.8 - 2 - 4 - 6 - 8 - 10 - 12 - 14 - 16 - 18 high level output voltage v om (v) high level output current i om ( a) reset hold time temperature during power supply rise 160 140 120 100 80 60 40 - 40 - 20 0 20 40 60 80 100 v cc =5v (cr=0.1 f) reset hold time temperature during power supply rise t pr (ms) ambient temperature ta ( c) watchdog timer monitoring time temperature 16 14 12 10 8 6 4 - 40 - 20 0 20 40 60 80 100 v cc =5v (cr=0.1 f) watchdog timer monitoring time temperature t wd (ms) ambient temperature ta ( c) reset time temperature (for watchdog timer) 3.5 3.0 2.5 2.0 1.5 1.0 0.5 - 40 - 20 0 20 40 60 80 100 v cc =5v (cr=0.1 f) reset time t wr (ms) ambient temperature ta ( c) c t value for reset hold time during power supply rise 10 5 10 4 10 3 10 2 10 1 10 - 3 10 - 2 10 - 1 10 0 10 0 10 1 hold time t wd (ms) c t capacitance ( f)
mitsumi system reset (with built-in watchdog timer) mm1035 c t value for reset time (for watchdog timer) 10 3 10 2 10 1 10 0 10 - 1 10 - 2 10 - 3 10 - 2 10 -1 10 0 10 1 reset time t wr (ms) c t capacitance ( f) c t value for watchdog timer monitoring time 10 4 10 3 10 2 10 1 10 0 10 -1 10 - 3 10 - 2 10 - 1 10 0 10 1 timer monitoring time t wd (ms) c t capacitance ( f)
|
