DESCRIPTION
   The X40430, X40431, X40434, X40435 combines power-on reset control, watchdog timer, supply voltage supervision, second and third voltage supervision, manual reset, and Block Lock™ protect serial EEPROM in one package. This combination lowers system cost, reduces board space requirements, and increases reliability.

FEATURES
• Monitoring voltages: 5V to 9V
• Independent core voltage monitor
• Triple voltage detection and reset assertion
   —Standard reset threshold settings. See selection table on page 2.
   —Adjust low voltage reset threshold voltages
      using special programming sequence
   —Reset signal valid to VCC = 1V
   —Monitor three separate voltages
• Fault detection register
• Selectable power-on reset timeout
   (0.05s, 0.2s, 0.4s, 0.8s)
• Selectable watchdog timer interval
   (25ms, 200ms, 1.4s or off)
• Debounced manual reset input
• Low power CMOS
   —25µA typical standby current, watchdog on
   —6µA typical standby current, watchdog off
   • Memory security
• 4Kbits of EEPROM
   —16 byte page write mode
   —5ms write cycle time (typical)
• Built-in inadvertent write protection
   —Power-up/power-down protection circuitry
   —Block lock protect 0, or 1/2, of EEPROM
• 400kHz 2-wire interface
• 2.7V to 5.5V power supply operation
• Available packages
   —14-lead SOIC, TSSOP

APPLICATIONS
• Communication Equipment
   —Routers, Hubs, Switches
   —Disk Arrays, Network Storage
• Industrial Systems
   —Process Control
   —Intelligent Instrumentation
• Computer Systems
   —Computers
   —Network Servers