CAT803 CATALYST [Catalyst Semiconductor], CAT803 Datasheet - Page 6

• Manufacturer Part Number: CAT803
• Description: 3-Pin Microprocessor Power Supply Supervisors
• Manufacturer: CATALYST [Catalyst Semiconductor]

CAT803, CAT809, CAT810
DETAILED DESCRIPTIOnS
RESET TIMInG
The reset signal is asserted LOW for the CAT803/
CAT809 and HIGH for the CAT80 when the power
supply voltage falls below the threshold trip voltage and
remains asserted for at least 40ms after the power
supply voltage has risen above the threshold.
V
The CAT803/CAT809/CAT80 protect µPs against
brownout failure. Short duration transients of 4µsec
or less and 00mV amplitude typically do not cause a
false RESET.
Figure 2 shows the maximum pulse duration of negative-
going V
Doc. No. 3004, Rev. X
CC
figure 2. Maximum Transient Duration Without Causing a Reset Pulse vs. Reset Comparator Overdrive
TRAnSIEnT RESPOnSE
CC
transients that do not cause a reset condition.
V
CC
RESET
RESET
V
5V
TH
0V
5V
0V
5V
0V
figure 1. Reset Timing Diagram
T
D
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
TH
- V
CC
).
(140msec
minimum)
T
R
CAT803, CAT809
CAT810
Characteristics subject to change without notice
TH
© 2007 by Catalyst Semiconductor, Inc.
- V
CC
), the maximum
CC
starts