CAT1025

The CAT1024 and CAT1025 are complete memory andsupervisory solutions for microcontroller-based systems.A 2k-bit serial EEPROM memory and a system powersupervisor with brown-out protection are integratedtogether in low power CMOS technology. Memoryinterface is via a 400kHz I2C bus

The CAT1025 provides a precision VCC sense circuitand two open drain outputs: one (RESET) drives highand the other (RESET) drives low whenever VCC fallsbelow the reset threshold voltage. The CAT1025 alsohas a Write Protect input (WP). Write operations aredisabled if WP is connected to a logic high.The CAT1024 also provides a precision VCCsensecircuit, but has only a RESET output and does not havea Write Protect input.

The power supply monitor and reset circuit protectmemory and system controllers during power up/downand against brownout conditions. Five resetthresholdvoltages support 5V, 3.3V and 3V systems. If power supplyvoltages are out of tolerance reset signals become active,preventing the systemmicrocontroller, ASIC or peripheralsfrom operating. Reset signals become inactive typically 200ms after the supply voltage exceeds the reset thresholdlevel. With both active high and low reset signals, interfaceto microcontrollers and other ICs is simple. In addition, theRESET pin or a separate input, MR, can be used as an input for push-button manual reset capability.

The CAT1024/25 memory features a 16-byte page. Inaddition, hardware data protection is provided by a VCCsense circuit that prevents writes to memory whenever VCCfalls below the reset threshold or until VCC reaches the resetthreshold during power up. Available packages include an 8-pin DIP, 8-pin SOIC, 8-pinTSSOP, 8-pin TDFN and 8-pin MSOP. The TDFN packagethickness is 0.8mm maximum. TDFN footprint is 3x3mm.