EEPROM Serial 2-Kb CPU Supervisor

The CAT1027 is a complete memory and supervisory solution for microcontroller-based systems. A EEPROM Serial 2-Kb CPU Supervisor and a system power supervisor with brown-out protection are integrated together in low power CMOS technology. Memory interface is via a 400 kHz I²C bus. The CAT1027 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. CAT1027 has only a RESET output. In addition, the RESET pin can be used as an input for push-button manual reset capability. The CAT1027 provides an auxiliary voltage sensor input, VSENSE, which is used to monitor a second system supply. The auxiliary high impedance comparator drives the open drain output, VLOW, whenever the sense voltage is below 1.25 V threshold. The CAT1027 is designed with a 1.6 second watchdog timer circuit that resets a system to a known state if software or a hardware glitch halts or 'hangs' the system. The CAT1027 features a watchdog timer interrupt input, WDI. The on-chip 2 k-bit EEPROM memory features a 16-byte page. In addition, hardware data protection is provided by a VCC sense circuit that prevents writes to memory whenever VCC falls below the reset threshold or until VCC reaches the reset threshold during power up. Available packages include an 8-pin DIP, 8-pin SOIC, 8-pin TSSOP, 8-pin TDFN and 8-pin MSOP. The TDFN package thickness is 0.8 mm maximum. TDFN footprint is 3x3 mm.