The LM809 and LM810M3X-4.00/NOPB 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 LM810M3X-4.00/NOPB 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 LM810M3X-4.00/NOPB 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 LM810M3X-4.00/NOPB are ideal for use in portable equipment.
Feature
- Precision Monitoring of Supply Voltages
- Available Threshold Options:
2.63 V, 2.93 V, 3.08 V, 4.38 V, 4.63 V
- Available Threshold Options:
- 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
