DESCRIPTION

These devices combine four popular functions, Power-on 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