TC1278/TC1279

DS21384B-page 4

© 2002 Microchip Technology Inc.

3.0

APPLICATIONS INFORMATION

3.1

Operation – Power Monitor

The TC1278/TC1279 provide the function of detecting

out-of-tolerance power supply conditions and warning

a processor-based system of impending power failure.

signal is asserted. On power-up, RESET is kept active

for approximately 350msec after the power supply has

reached the selected tolerance. This allows the power

supply and microprocessor to stabilize before RESET

is released.

FIGURE 3-1:

Timing Diagram –

Power Up (TC1279)

FIGURE 3-2:

Timing Diagram –

Power Down (TC1279)

FIGURE 3-3:

Timing Diagram –

Power Up (TC1278)

FIGURE 3-4:

Timing Diagram –

Power Down (TC1278)

4.75V

4.00V

tR

VCCTP

VCC

RESET

tRPU1

VOH

RESET

4.75V

4.00V

RESET

4.74V

RESET

4.00V