ADM697

The ADM696 / ADM697 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 ADM696 / ADM697 are available in 16-pin DIP and small outline packages 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 V_CC as low as 1 V.
• A Reset pulse if the optional watchdog timer has not been toggled within specified time.
• Separate watchdog time-out 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 V_CC.
• Battery backup switching for CMOS RAM, CMOS micro-processor or other low power logic
• (ADM696).
• Write protection of CMOS RAM or EEPROM (ADM697).

The ADM696 / ADM697 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 V_CC 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.