RT9179

2

DS9179-08 March 2007

www.richtek.com

Function Block Diagram

Functional Pin Description

Pin No.

Pin Name

Pin Function

1

VIN

Power Input Voltage

2

GND

Ground

3

EN

Chip Enable (Active High)

4

ADJ

Adjust Output Voltage. The output voltage is set by the internal feedback resistors when

this pin grounded. If external feedback resistors are applied, the output voltage will be:

) Volts

5

VOUT

Output Voltage

2

1

R

R

Current-Limit

and

Thermal Protection

MOS

Driver

VOUT

Shutdown

and

Logic Control

VIN

Error

Amplifier

1.175V

V

REF

ADJ

EN

GND

Thermal

SHDN

+_

Typical Application Circuit

2

1

R

R

1

+

Adjustable Operation

Note: The external feedback resistors are in hundreds of OHM to hundreds of KOHM ranges.

V

) Volts

VIN

VOUT

ADJ

EN

RT9179CB

C

2

1uF

1uF

0.1uF

R

2

R

1

V

OUT

V

IN

C

1

C

3

GND

Chip Enable