CAT812 Catalyst Semiconductor, CAT812 Datasheet - Page 6

• Manufacturer Part Number: CAT812
• Description: 4-pin Microprocessor Voltage Supervisor
• Manufacturer: Catalyst Semiconductor

CAT811, CAT812
DETAILED DESCRIPTION
RESET TIMING
The reset signal is asserted LOW for the CAT811 and
HIGH for the CAT812 when the power supply voltage
falls below the threshold trip voltage and remains
asserted for at least 140ms after the power supply
voltage has risen above the threshold.
V
The CAT811/812 protect µPs against brownout
failure. Short duration transients of 4µs or less and
100mV amplitude typically do not cause a false
RESET.
Figure 2 shows the maximum pulse duration of
negative-going V
reset condition.
Doc. No. MD-3005 Rev. S
CC
TRANSIENT RESPONSE
Voltage
RESET
RESET
Supply
Power
CC
5V
0V
5V
0V
5V
0V
transients that do not cause a
Figure 2. Maximum Transient Duration without Causing a
Reset Pulse vs. Reset Comparator Overdrive
Figure 1. Reset Timing Diagram
30
25
20
15
10
5
0

1
RESET OVERDRIVE V
CAT8xxM
10
6
As the amplitude of the transient goes further below
the threshold (increasing V
pulse duration decreases. In this test, the V
from an initial voltage of 0.5V above the threshold and
drops below it by the amplitude of the overdrive
voltage (V
T
100
TH
AMB
CAT8xxZ
- V
Threshold
CC
= 25°C
Voltage
(mV)
TH
1000
- V
CC
).
minimum
140ms
Reset Timeout Period
Characteristics subject to change without notice
TH
- V
CAT812
CAT811
CC
© Catalyst Semiconductor, Inc.
), the maximum
CC
starts