© 2002 Microchip Technology Inc.

DS21384B-page 5

TC1278/TC1279

3.2

ing and reset timing during power-up, power-down,

and brownout/sag conditions, and rejects negative-

going transients (glitches) on the power supply line.

Figure 3-5 shows the maximum transient duration vs.

maximum negative excursion (overdrive) for glitch

rejection. Any combination of duration and overdrive

that lays under the curve will not generate a reset

signal. Combinations above the curve are detected as

a brownout or power-down. Transient immunity can be

improved by adding a capacitor in close proximity to the

FIGURE 3-5:

MAXIMUM TRANSIENT

DURATION VS.

OVERDRIVE FOR GLITCH

REJECTION AT 25°C

RESET COMPARATOR OVERDRIVE,

5

3

2

4

1

0

1

5

100

1000

°C

Duration

Overdrive

TC1278/9