CAT1162

CAT1161/2 (16K) Supervisory Circuits with I2C Serial CMOS EEPROM, Precision Reset Controller and Watchdog Timer FEATURES s Watchdog monitors SDA signal (CAT1161) s 400kHz I C bus compatible s 2.7V to 6.0V operation s Low power CMOS technology s 16-Byte page write buffer s Built-in inadvertent write protection 2 s Active high or low reset — Precision power supply voltage monitor — 5V, 3.3V and 3V systems — Five threshold voltage options s 1,000,000 Program/Erase cycles s Manual Reset s 100 Year data retention s 8-pin DIP or 8-pin SOIC s Commercial and industrial temperature ranges — VCC lock out — Write protect pin, WP DESCRIPTION The CAT1161/2 is a complete memory and supervisory solution for microcontroller-based systems. A serial EEPROM memory (16K) with hardware memory write protection, a system power supervisor with brown out protection and a watchdog timer are integrated together in low power CMOS technology. Memory interface is via an I2C bus. The 1.6-second watchdog circuit returns a system to a known good state if a software or hardware glitch halts or “hangs” the system. The CAT1161 watchdog monitors the SDA line, making an additional PC board trace unnecessary. The lower cost CAT1162 does not have a watchdog timer. The power supply monitor and reset circuit protects memory and system controllers during power up/down and against brownout conditions. Five reset threshold voltages support 5V, 3.3V and 3V systems. If power supply voltages are out of tolerance rese...