njm2102 - 1 - ver.2013-03-06 system reset ic general description package outline the njm2102 possesses two functions. one is to detect a voltage which decays from the desired voltage and generate a warning signal. and also, the njm2102 holds the warning signal for a certain term after the specified voltage is obtained or recovered. the other one (watch dog timer) is to identify missing clocks of microprocessors. therefore, it should be said that the njm2102 is ideal to protect any microprocessors from the fales operations induced by undesired condition. features internal watch dog timer precise detection of supply voltage down (4.2v 2.5%) package outline dip8, dmp8, sip8 bipolar technology pin configuration block diagram pin function 1. c t 2. reset 3. ck 4. gnd 5. v + 6. v ref 7. v s 8. reset njm2102l (sip8) njm2102d (dip8) njm2102m (dmp8) njm2102d njm2102m njm2102l
njm2102 - 2 - ver.2013-03-06 absolute maximum ratings (t a =25c) parameter symbol ratings unit supply voltage v + 20.0 v input voltage v s v + +0.3 (<20.0) v input voltage v ck 20.0 v (dip8) 500 (dmp8) 300 power dissipation p d (sip8) 800 mw operating temperature range t opr -40 to +85 c storage temperature range t stg -40 to +125 c electrical characteristics (v + =5v, t a =25c) parameter symbol condition min. typ. max. unit supply current i cc watch dog timer operating - 0.65 1.00 ma detection voltage 1 v sl falling down supply voltage 4.10 4.20 4.30 v detection voltage 2 v sh rising up supply voltage 4.20 4.30 4.40 v hysteresis width v hys v hys = v sl - v sh 50 100 150 mv reference voltage v ref 1.217 1.235 1.253 v supply voltage regulation ? v ref1 v + = 3.5v to 18v -10 +3 +10 mv reference voltage load regulation ? v ref2 i out = -200a to +5a -5 - +5 mv ck input threshold voltage v th 0.70 1.24 1.90 v ck input current 1 i ih v ck = 5.0v - 0 1.0 a ck input current 2 i il v ck = 0.0v -1.0 -0.1 - a c t charge current 1 i ctc1 v ct = 1.0v watch dog timer operating 20 50 110 a c t charge current 2 i ctc2 v ct = 0.0v power on reset operating 0.6 1.4 3.0 a c t discharge current 1 i ctd1 v ct = 1.0v watch dog timer operating 6 9 13 a c t discharge current 2 i ctd2 v ct = 0.0v power on reset operating 100 600 - a high level output voltage 1 v oh1 v s =open. reset i = -5a 4.5 4.9 - v high level output voltage 2 v oh2 v s =0v, i reset = -5ma 4.5 4.9 - v output saturation voltage 1 v ol1 v s =0v, reset i =3ma - 0.2 0.4 v output saturation voltage 2 v ol2 v s =0v, reset i =10ma - 0.3 0.5 v output saturation voltage 3 v ol3 v s =open. i reset =3ma - 0.2 0.4 v output saturation voltage 4 v ol4 v s =open. i reset =10ma - 0.3 0.5 v output sink current 1 i ol1 v s =0v, reset v =1.0v 20 70 - ma output sink current 2 i ol2 v s =open. reset v =1.0v 20 70 - ma reset minimum s upply voltage 1 v ccl1 reset v =0.4v, reset i =0.2ma - 0.8 1.2 v reset minimum supply voltage 2 v ccl2 v reset =v + -0.1v, r l (2pin-gnd)=1m ? - 0.8 1.2 v ac characteristics (v + =5v, t a =25c) parameter symbol condition min. typ. max. unit v + input pulse width t pi v cc 5v 4v - 10 - s ck input pulse width t ckw ck or - 1.8 - s ck input frequency t ck - 12 - s watch dog timer watching time t wd c t =0.1f - 10 - ms watch dog timer reset time t wr c t =0.1f - 2 - ms reset signal hold time t pr c t =0.1f, v + - 100 - ms propagation delay from v + t pd1 reset pin, r l =2.2k ? , c l =100pf - 2 - s propagation delay from v + t pd2 reset pin r l =2.2k ? , c l =100pf - 3 - s output rise time t r r l =2.2k ? , c l =100pf - 1.0 - s output fall time t f r l =2.2k ? , c l =100pf - 0.1 - s
njm2102 - 3 - ver.2013-03-06 timing chart
njm2102 - 4 - ver.2013-03-06 terminal function pin. no symbol function inside equivalent circuit 1 c t pin connection to capacitor, set the reset holding time 2 reset reset output 3 ck clock input
njm2102 - 5 - ver.2013-03-06 terminal function pin. no symbol function inside equivalent circuit 4 gnd ground 5 v + operating voltage 6 v ref ref amp output 7 v s comparator s input 8 reset reset output internal pull up resistor
njm2102 - 6 - ver.2013-03-06 typical characteristics operating current vs. operating voltage output voltage vs. operating voltage output voltage vs. operating voltage detect voltage vs. ambient temperature satulation voltage vs. output sink current satulation voltage vs. output sink current
njm2102 - 7 - ver.2013-03-06 typical characteristics high level output voltage vs. high level output current reference voltage vs. reference current high output voltage vs. high level output current reference voltage vs. ambient temperature reference voltage vs. operating voltage
njm2102 - 8 - ver.2013-03-06 typical characteristics reset hold time at transient reset time 1 watch dog timer observation time minimum input pulse width vs. c t wr ( sec ) timin g ca p acitor c t (
njm2102 - 9 - ver.2013-03-06 application circuit 1. 5v supply voltage supervisory and watch-dog timer voltage supply is detected through v s . detected voltage is v sh , v sl . if minimum input pulse width t pi needs extend, add external capacitor c between v s terminal and gnd. (please refer to typical characteristics : minimum input pulse width vs c) 2. 5v supply voltage supervisiory (externally fine tunning type) v s detecting voltage can be externally adjusted. detecting voltage can be decided by divider resistor of ic inside. detecting voltage can be set by external r1, r2. the external resistor r1, r2 are required to be set in value less than 1 / 10 in comparing to divideing resistor of ic inside. please refere to following table. r 1 (k ? ) r 2 (k ? ) detecting voltage : v sl (v) detecting voltage : v sh (v) 10 3.9 4.34 4.44 9.1 3.9 4.08 4.18
njm2102 - 10 - ver.2013-03-06 3. compulsory resetting attached (reset hold attached) *pin 7 to be grounded when sw. on. reset (8pi n) become low : reset (pin2) become high. by putting signal in the reset pin, and tr swich on reset pin become low and reset pin high. [caution] the specifications on this databook are only given for information , without any guarantee as regards either mistakes or omissions. the application circuits in this databook are described only to show representative usages of the product and not intended for the guarantee or permission of any right including the industrial rights.
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