The CAT1025 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 CAT1025 provides a precision VCCsense circuit and two open drain outputs: one (RESET) drives high and the other (RESET) drives low whenever VCCfalls below the reset threshold voltage. The CAT1025 also has a Write Protect input (WP). Write operations are disabled if WP is connected to a logic high.The power supply monitor and reset circuit protect memory and system controllers during power up/down and against brownout conditions. Five reset threshold voltages support 5.0 V, 3.3 V and 3.0 V 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 other ICs is simple. In addition, theRESETpin or a separate input,MR, can be used as an input for push-button manual reset capability.The CAT1025 memory features a 16-byte page. In addition, hardware data protection is provided by a VCCsense circuit that prevents writes to memory whenever VCCfalls below the reset threshold or until VCCreaches 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 3 x 3 mm.