3-pin voltage supervisor (reset IC) with active-low, push-pull reset for supply monitoring

The LM809 and LM810 microprocessors supervisory circuits can be used to monitor the power

supplies in microprocessor and digital systems. They provide a reset to the microprocessor during

power-up, power-down and brown-out conditions.

The function of the LM809 and LM810 are to monitor the VCC supply

voltage, and assert a reset signal whenever this voltage declines below the factory-programmed

reset threshold. The reset signal remains asserted for 240 ms after VCC

rises above the threshold. The LM809 has an active-low RESET output, while

the LM810 has an active-high RESET output.

Seven standard reset voltage options are available, suitable for monitoring 5-V, 3.3-V,

and 3-V supply voltages.

With a low supply current of only 15 µA, the LM809 and LM810 are ideal for use in

portable equipment.