The CAT1026 is a complete memory and supervisory solution for microcontroller-based systems. A 2 k-bit serial EEPROM memory and a system power supervisor with brown-out protection are integrated together in low power CMOS technology. Memory interface is via a 400 kHz IC bus. The CAT1026 provides a precision VCC sense circuit with five reset threshold voltage options that support 5.0 V 3.3 V and 3.0 V systems. The power supply monitor and reset circuit protects memory and systems controllers during power up/down and against brownout conditions. If power supply voltages are out of tolerance reset signals become active preventing the system microcontroller ASIC or peripherals from operating. The CAT1026