DESCRIPTION ¡El CAT1024 and CAT1025 are complete memory and supervisory solutions for microcontroller-based systems. A 2k-bit serial EEPROM memory and a system power supervisor with brown-out protection are integrated together in low power CMOS techno– logy. Memory interface is via a 400 kHz I2 C bus. ¡El CAT1025 provides a precision VCC sense circuit and two open drain outputs: one (RESET) drives high and the other (RESET ¯¯¯¯¯¯) drives low whenever VCC falls below the reset threshold voltage. ¡El CAT1025 also has a Write Protect input (WP). Write operations are disabled if WP is connected to a logic high. ¡El CAT1024 also provides a precision VCC sense circuit, but has only a RESET ¯¯¯¯¯¯ output and does not have a Write Protect input. ¡El 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 V, 3.3 V and 3 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, the RESET ¯¯¯¯¯¯ pin or a separate input, MR ¯¯¯, can be used as an input for push-button manual reset capability. ¡El CAT1024/25 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 PDIP and a surface mount 8-pin SO, 8-pin TSSOP, 8-pin TDFN and 8-pin MSOP packages. ¡El TDFN package thickness is 0.8 mm maximum. TDFN footprint is 3 x 3 mm.