CAT853, CAT863, CAT859, CAT869

4

Doc. No. 3026, Rev. B

© 2007 by Catalyst Semiconductor, Inc.

Characteristics subject to change without notice

5V

0V

5V

0V

Threshold

Voltage

140ms

minimum

Reset Timeout Period

Power

Supply

Voltage

RESET

DETAILED DESCRIPTIONS

RESET TIMING

The reset signal is asserted low for the CAT853, CAT863,

CAT859, and CAT869 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.

Figure 2. Maximum Transient Duration Without Causing a Reset Pulse vs. Reset Comparator Overdrive

The CAT853, CAT863, CAT859, and CAT869 protect

μPs against brownout failure. Short duration transients

of 4μsec or less and 100mV amplitude typically do not

cause a false RESET.

Figure 2 shows the maximum pulse duration of negative-

Figure 1. Reset Timing Diagram

As the amplitude of the transient goes further below

from an initial voltage of 0.5V above the threshold and

drops below it by the amplitude of the overdrive voltage