The LM809M3X-2.45 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 LM809M3X-2.45 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 LM809M3X-2.45 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 LM809M3X-2.45 and LM810 are ideal for use in portable equipment.

Precision Monitoring of Supply Voltages

Available Threshold Options:

2.63 V, 2.93 V, 3.08 V, 4.38 V, 4.63 V

Superior Upgrade to MAX809 and MAX810

Fully Specified Over Temperature

140-ms Minimum Power-On Reset Pulse Width,

240-ms Typical

Active-Low RESET Output (LM809)

Active-High RESET Output (LM810)

Ensured RESET Output Valid for VCC ≥ 1 V

Low Supply Current, 15-μA Typical

Power Supply Transient Immunity