DESCRIPTION
The X4283/85 combines four popular functions, Power-on Reset Control, Watchdog Timer, Supply Volt age Supervision, and Block Lock protect serial EEPROM memory in one package. This combination lowers system cost, reduces board space require ments, and increases reliability.

FEATURES
• Selectable watchdog timer
• Low VCC detection and reset assertion
   —Four standard reset threshold voltages
   —Adjust low VCC reset threshold voltage using special programming sequence
   —Reset signal valid to VCC = 1V
• Low power CMOS
   —<20µA max standby current, watchdog on
   —<1µA standby current, watchdog OFF
   —3mA active current
• 128Kbits of EEPROM
   —64 byte page write mode
   —Self-timed write cycle
   —5ms write cycle time (typical)
• Built-in inadvertent write protection
   —Power-up/power-down protection circuitry
   —Protect 0, 1/4, 1/2, all or 64, 128, 256 or 512 bytes of EEPROM array with programmable Block Lock™ protection
• 400kHz 2-wire interface
• 2.7V to 5.5V power supply operation
• Available packages
   —8-lead SOIC
   —8-lead TSSOP