Microprocessor Supervisor with Backup Battery Switchover, Watchdog Feature, Power Fail Warning, 4.4V Threshold Voltage, Active Low Reset and 100mA Output Current
The ADM690-ADM695 family of supervisory circuits offers 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 complete family provides a variety of configurations to satisfy most microprocessor system requirements.
The ADM690, ADM692 and ADM694 are available in 8-pin DIP packages and provide:
Power-on reset output during power-up, power-down and brownout conditions. The RESET output remains operational with VCC as low as 1 V.
Battery backup switching for CMOS RAM, CMOS microprocessor or other low power logic.
A reset pulse if the optional watchdog timer has not been toggled within a specified time.
A 1.3 V threshold detector for power fail warning, low battery detection, or to monitor a power supply other than +5 V.
The ADM691, ADM693 and ADM695 are available in 16-pin DIP and small outline packages and provide three additional functions.
Write protection of CMOS RAM or EEPROM.
Adjustable reset and watchdog timeout periods.
Separate watchdog timeout, backup battery switchover, and low VCC status outputs.
The ADM690-ADM695 family is fabricated using an advanced epitaxial CMOS process combining low power consumption (5 mW), extremely fast Chip Enable gating (5 ns) and high reliability. RESET assertion is guaranteed with VCC as low as 1 V. In addition, the power switching circuitry is designed for minimal voltage drop thereby permitting increased output current drive of up to 100 mA without the need for an external pass transistor.
### Features and Benefits
Superior Upgrade for MAX690–MAX695
Specified Over Temperature
Low Power Consumption (5 mW)
Precision Voltage Monitor
Reset Assertion Down to 1 V VCC
Low Switch On-Resistance 1.5 O Normal, 20 O in Backup
High Current Drive (100 mA)
Watchdog Timer—100 ms, 1.6 s, or Adjustable
600 nA Standby Current
Automatic Battery Backup Power Switching
Extremely Fast Gating of Chip Enable Signals (5 ns)
