DESCRIPTION

These devices combine four popular functions, Poweron Reset Control, Watchdog Timer, Supply Voltage Supervision, and Block Lock Protect Serial EEPROM Memory in one package. This combination lowers system cost, reduces board space requirements, and increases reliability.

FEATURES

? Selectable watchdog timer

? Low VCC detection and reset assertion

—Five standard reset threshold voltages

—Re-program low VCC reset threshold voltage using special programming sequence

—Reset signal valid to VCC = 1V

? Determine watchdog or low voltage reset with a volatile flag bit

? Long battery life with low power consumption

—<50μA max standby current, watchdog on

—<1μA max standby current, watchdog off

—<400μA max active current during read

? 64Kbits of EEPROM

? Built-in inadvertent write protection

—Power-up/power-down protection circuitry

—Protect 0, 1/4, 1/2 or all of EEPROM array with Block Lock? protection

—In circuit programmable ROM mode

? 2MHz SPI interface modes (0,0 & 1,1)

? Minimize EEPROM programming time

—32-byte page write mode

—Self-timed write cycle

—5ms write cycle time (typical)

? 2.7V to 5.5V and 4.5V to 5.5V power supply operation

? Available packages

—8-lead PDIP, 14-lead SOIC