mic811luy Micrel Semiconductor, mic811luy Datasheet - Page 6

• Manufacturer Part Number: mic811luy
• Description: Mic811/mic812 Microprocessor Reset Circuits
• Manufacturer: Micrel Semiconductor

MIC811/812
Applications Information
Microprocessor Reset
The /RESET (or RESET) pin is asserted whenever V
below the reset threshold voltage. The /RESET pin remains
asserted for a period of 140ms after V
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
V
V
The MIC811/812 are relatively immune to negative-going V
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.
MIC811/812
CC
CC
as low as 1V.
Transients
CC
has risen above the
CC
falls
CC
6
/RESET Valid at Low Voltage
A resistor can be added from the /RESET pin to ground to
ensure the /RESET output remains low with V
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.
MIC81 1
V CC
RESET
Reset Valid to V
V CC
100K
CC
RESET
= 0V
V CC
µP
September 2005
CC
down to
Micrel