點晶科技股份有限公司

SILICON TOUCH TECHNOLOGY INC.

Voltage Detecting IC

-1 -

Version

：A.017

PS121

PS121

Voltage Detecting IC

General Description

PS121 is specially designed for +5V power good signal generating. Power good

signal notifies microprocessor whether the +5V supply voltage is ready, therefore it can

provide a stable and reliable power supply and computing environment.

Delay circuit is also built-in to provide delay time by adding an external capacitor.

Features

1. Power Good Logic to Check +5V

2. Adjustable delay time

3. 4-pin SIP package

Block Diagram

1

2

+5V INPUT

GND

DELAY

CAPACITOR

PG

OUTPUT

4

3

1.25 V

23.6K

10K

I

d

V

th_cd

10K