The UM809/810 series are ultra low current, cost effective system supervisory circuits designed to monitor the power supplies in digital systems. They provide a reset signal to the host processor when necessary, offer excellent circuit reliability & low cost by eliminating external component and adjustment when used with +5V, +3.3V, +3.0V or other voltage powered circuits.

The reset output is driven active within 10µs of power supply falling through the reset voltage threshold. Reset is keeping active for a minimum of 140ms after system power supply has risen above the reset threshold. Reset threshold suitable for operation with variety of supply voltage are available.

UM809 has an active-low reset output while UM810 has an active-high reset output. The UM809/810 are optimized to reject fast transient glitches on the power supply line, and the reset output are guaranteed to be in the correct logic state for power supply V_CC down to 1V.

Each of these ICs consists of a voltage reference comparator, resistors for detector threshold setting, delay generator, output driver & hysteresis circuit. The reset threshold & time delay are fixed with high accuracy internally and does not require any external adjustment.  

Low supply current of 3µA (V_CC=3V) makes UM809/810 ideal for low power application. Both devices are available in 3 Pin SOT323 or SOT23 packages.

- Wide Operation Voltage Range of 1V to 10V

- Typical Quiescent Current of 3μA

- No External Components

- 3-Pin Small SOT323 and SOT23 Packages

- V_CC Transient Immunity

- Correct Logic Output Guaranteed to V_CC=1.0V

- Precision V_CC Monitor for 2.5V, 3.0V, 3.3V and 5.0V Supplies

- Available in 2 Output Configurations

  Push-Pull Low Active Reset Output (UM809)

  Push-Pull High Active Reset Output (UM810)

- Wide Operation Temperature: -40°C to +85°C