CAT1021

CAT1021, CAT1022, CAT1023 Supervisory Circuits with I2C Serial 2k-bit CMOS EEPROM, Manual Reset and Watchdog Timer FEATURES Precision Power Supply Voltage Monitor — 5V, 3.3V and 3V systems — Five threshold voltage options Watchdog Timer Active High or Low Reset — Valid reset guaranteed at VCC = 1V 400kHz I2C Bus 2.7V to 5.5V Operation Low power CMOS technology 16-Byte Page Write Buffer Built-in inadvertent write protection — WP pin (CAT1021) All supervisors have a 1.6 second watchdog timer circuit that resets a system to a known state if software or a Manual Reset Input hardware glitch halts or “hangs” the system. For the www.DataSheet4U.com CAT1021 and CAT1022, the watchdog timer monitors 100 year data retention the SDA signal. The CAT1023 has a separate watchdog Industrial and extended temperature ranges timer interrupt input pin, WDI. 8-pin DIP, SOIC, TSSOP, MSOP or TDFN The power supply monitor and reset circuit protect (3 x 3 mm foot-print) packages memory and system controllers during power up/down — TDFN max height is 0.8mm and against brownout conditions. Five reset threshold voltages support 5V, 3.3V and 3V systems. If power supply voltages are out of tolerance reset signals become active, preventing the system microcontroller, ASIC or peripherals from operating. Reset signals become inactive typically 200 ms after the supply voltage exceeds the reset threshold level. With both active high and low reset signals, interface to microcontrollers and ¯¯¯¯¯¯ pin or a othe...