ASM802M

The ASM690A / ASM692A / ASM802L / ASM802M / ASM805L offers complete single chip solutions for power supply monitoring and control battery functions in microprocessor systems. Each device implements four functions: Reset control,watchdog monitoring, battery-backup switching and powerfailure monitoring. In addition to microprocessor reset under power-up and power-down conditions, ASM802M provide battery-backup switching to maintain control in power loss and brown-out situations. Additional monitoring capabilities can provide an early warning of unregulated power supply loss before the voltage regulator drops out. The important features of these four functions are:

• 1.6 second watchdog timer to keep microprocessor responsive
• 4.40V or 4.65V VCC threshold for microprocessor reset at power-up and power-down
• SPDT (Single-pole, Double-throw) PMOS switch connects backup power to RAM if VCC fails
• 1.25V threshold detector for power loss or general purpose voltage monitoring

These features are pin-compatible with the industry standard
power-supply supervisors. Short-circuit and thermal protection
have also been added. The ASM690A / ASM802L / ASM805L
generate a reset pulse when the supply voltage drops below
4.65V and the ASM692A / ASM802M generate a reset below
4.40V. The ASM802L / ASM802M have power-fail accuracy to
± 2%. The ASM805L is the same as the ASM690A except that
RESET is provided instead of RESET.