MIC811/812

Micrel

MIC811/812

6

September 2005

Applications Information

Microprocessor Reset

below the reset threshold voltage. The /RESET pin remains

reset threshold voltage. The reset function ensures that the

microprocessor is properly reset and powers up in a known

condition after a power failure. /RESET will remain valid with

glitches below the reset threshold.Typically, a negative-going

transient 125mV below the reset threshold with a duration of

20µs or less will not cause a reset.

Interfacing to Bidirectional Reset Pins

The MIC811/812 can interface with µPs with bidirectional

reset pins by connecting a 4.7kΩ resistor in series with the

MIC811/812 output and the µP reset pin.

/RESET Valid at Low Voltage

A resistor can be added from the /RESET pin to ground to

0V. A 100kΩ resistor connected from the /RESET to ground

is recommended. The size of the resistor should be large

enough not to load the output excessively and small enough

to pull-down any stray leakage currents.

VCC

RESET

µP

RESET

VCC

MIC811

VCC

100K