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.