Microprocessor Supervisory Circuit

The ADM8696 / ADM8697 supervisory circuits offer complete single chip solutions for power supply monitoring and battery control functions in microprocessor systems. These functions include µP reset, backup battery switchover, watchdog timer, CMOS RAM write protection and power failure warning.

The ADM8696 / ADM8697 are available in 16-pin DIP and small outline packages (including TSSOP) and provide the following functions:

* Power-On Reset output during power-up, power-down and brownout conditions. The RESET voltage threshold is adjustable using an external voltage divider. The RESET output remains operational with VCC as low as 1 V.

* A Reset pulse if the optional watchdog timer has not been toggled within specified time.

* Separate watchdog timeout and low line status outputs.

* Adjustable reset and watchdog timeout periods.

* A 1.3 V threshold detector for power fail warning, low battery detection or to monitor a power supply other than VCC.

* Battery backup switching for CMOS RAM, CMOS micro-processor or other low power logic (ADM8696).

* Write protection of CMOS RAM or EEPROM (ADM8697).

* Upgrade for ADM696/ADM697

* Specified Over Temperature

* Adjustable Low Line Voltage Monitor

* Power OK/Reset Time Delay

* Reset Assertion Down to 1 V VCC

* Watchdog Timer—100 ms, 1.6 s, or Adjustable

* Low Switch On Resistance

* 0.7 Ω Normal, 7 Ω in Backup