1FEATURES

2• Precise Monitoring of 3V, 3.3V, and 5V Supply

Voltages

• Fully specified over temperature

• 140ms min. Power-On Reset Pulse Width,

240ms Typical

– Active-low RESET Output (MCP809)

– Active-high RESET Output (MCP810)

• Specified RESET Output Valid for V CC≥1V

• Low Supply Current, 15μA typical

• Power supply transient immunity

APPLICATIONS

• Microprocessor Systems

• Computers

• Controllers

• Intelligent Instruments

• Portable/Battery-Powered Equipment

• Automotive

DESCRIPTION

The MCP809/810 microprocessor 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 MCP809/810 is 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

240ms after VCC rises above the threshold. The

MCP809 has an active-low RESET output, while the

MCP810 has an active-high RESET output.

Seven standard reset voltage options are available,

suitable for monitoring 5V, 3.3V, and 3V supply

voltages.

With a low supply current of only 15μA, the

MCP809/810 are ideal for use in portable equipment.

The MCP809/MCP810 are available in the 3-pin

SOT23 package.