Data Sheet

2

Rev. 1.7, 2007-03-20

TLE 4290

Power Good

The Power Good PG pin informs e.g. the microcontroller in case the output voltage has

fallen below the lower threshold

V

battery voltage at first the power good signal remains LOW. When the output voltage has

reached the higher threshold

V

power good delay time

t

can be set by the user with an external capacitor at pin D according to the requirements

of the application.

The Power Good circuitry supervises the output voltage. In case

V

Power Good switching threshold

V

reaction time. The Power Good LOW signal is generated down to an output voltage

V

Q

to 1 V. A LOW signal at the Power Good pin informs that the battery was lost and

memory is no longer valid.

The feature should be used in combination with a microcontroller with internal reset.

Figure 1

Block Diagram

AEB02823

Current

and

Saturation

Control

Band-

Gap-

Reference

TLE 4290

Power

Good

Control

PG

Q

I

D

GND

15

2

4