MM1136

MITSUMI IC for System Reset (with built-in watchdog timer) MM1136 IC for System Reset (with built-in watchdog timer) Monolithic IC MM1136 Outline March 27, 2000 These ICs were developed to drive low voltage batteries, and have a watchdog timer with built-in microcomputer reset voltage detection circuit and low battery detection circuit. A single reference voltage is used for low battery voltage detection and microcomputer reset voltage . detection, so detection voltage difference is uniform ( = 0.2V). Further, there is a built-in watchdog timer for . operation diagnosis, which prevents the system from running wild by generating an intermittent reset pulse during system mis-operation. Features 1. Accurate voltage drop detection voltage 1. Low battery detection 3.4V±3% 2. Power supply voltage detection 3.2V±3% 3. Detection voltage error 0.2V±20mV 1-2 4. Hysteresis Both 50mV typ. 2. Watchdog function stop pin (can be made to function only as reset IC during VCC rise) 3. Low current consumption 150µA typ. Package SOP-8C (MM1136XF) Applications 1. 3V cordless telephones 2. Various types of small, handy equipment Series Table Model MM1136 VSLB 3.4V VSLR 3.2V TPR 100ms TWD 100ms TWR 2ms TPR : Reset hold time during VCC rise TWD : Timer monitoring time TWR : Reset time VSLB : Battery check detection voltage VSLR : Reset detection voltage *C =0.02µF T MITSUMI IC for System Reset (with built-in watchdog timer) MM1136 Pin Assignment 1 2 8 7 6 5 3 4 5 1 2 3 4 6 7 SOP-8C (TOP VIEW) 8 TC BC (RESET) CK GND VCC RCT VS RESET Pin Description Pin No. 1 2 3 4 5 6 7 8 Pin name TC BC (RESET) CK GND VCC RCT VS ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Function TWD, TWR, TPR time setting pins. Battery check output pin (RESET low level output) for 3.4V Clock input pin GND pin Power supply voltage input pin Watchdog timer stop pin Operation OPEN, Stop connect to GND Detection voltage fine adjustment pin Reset output pin (low output) RESET Block Diagram MITSUMI IC for System Reset (with built-in watchdog timer) MM1136 Absolute Maximum Ratings Item Power supply voltage Voltage applied to input pin Voltage applied to output pin Allowable loss Storage temperature Symbol VCC max. VIN VOUT Pd TSTG Rating -0.3~+7 -0.3~VCC+0.3 ( < +7) = -0.3~VCC+0.3 ( < +7) = 450 -40~+125 Units V V V mW °C Recommended Operating Conditions Item Power supply voltage -------------------------------------------------- Symbol VCC IOLR IOLC VCKH VCKL TWD tRCK, tFCK tRVCC tFVCC CT TOP Rating +2.5~+6.5 0~1.5 0~1.5 1.4<