Battery Backup Circuits

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ADM693 µP Supervisor with Backup Battery Switchover, Watchdog Feature, Power Fail Warning, 4.4V Threshold Voltage, 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 backup battery switchover, watchdog timer, µP reset, CMOS RAM write protection, and power failure warning.
http://www.analog.com/en/prod/0,,766_822_ADM693%2C00.html
ADM690 Functions: 4.65 V Reset, Battery Switchover, Watchdog Timer, Power Fail Input
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, CMOS RAM write protection, watchdog timer, and power failure warning. The complete family provides a variety of configurations to satisfy most microprocessor system requirements.
http://www.analog.com/en/prod/0,,766_822_ADM690%2C00.html
ADM800 µP Supervisor, Adjustable Reset and Watchdog Periods
The ADM691A/ADM693A/ADM800L/ADM800M 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, watchdog timer, CMOS RAM write protection, backup-battery switchover, and power-failure warning. The family of products provides an upgrade for the MAX691A/93A/800M family of products.
http://www.analog.com/en/prod/0,,766_822_ADM800%2C00.html
ADM691 µP Supervisor with Backup Battery Switchover, 50 ms Nominal Adjustable Reset Period, Adjustable Watchdog Period, Chip Enable Signals, 4.65V Threshold Voltage, Watchdog, Backup Battery and Low Vcc Status O/Ps 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.
http://www.analog.com/en/prod/0,,766_822_ADM691%2C00.html
ADM690A µP Supervisor with Backup Battery Switchover, Watchdog Feature, Power Fail Warning, 4.65V Threshold Voltage, Active Low Reset
The ADM690A/ADM692A/ADM802L/M/ADM805L/M family of supervisory circuits offers complete single chip solutions for power supply monitoring and battery control functions in microprocessor systems. These functions include mP reset, backup battery switchover, watchdog timer, and power failure warning. On the ADM690A/ADM802L/ADM805L the reset voltage threshold is 4.65 V. On the ADM692A/ADM802M/ ADM805M, the reset voltage threshold is 4.40 V.
http://www.analog.com/en/prod/0,,766_822_ADM690A%2C00.html