CAT803, CAT809, CAT810

6

Doc. No. 3004, Rev. X

© 2007 by Catalyst Semiconductor, Inc.

Characteristics subject to change without notice

0V

CAT803, CAT809

5V

0V

5V

RESET

RESET

(140msec

minimum)

CAT810

0V

5V

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.

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

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-

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