RT9009

2

DS9009-01 April 2011

www.richtek.com

Typical Application Circuit

Function Pin Description

Figure 1. Adjustable Operation

Note: The value of R2 should be less than 80k to

maintain regulation.

Pin No.

Pin Name

Pin Function

1

VIN

Power Supply Input.

2

EN

Chip Enable (Active High). When the EN goes to a logic low, the device will be

shutdown.

3

VOUT

Regulator Output.

4

ADJ

Output Voltage Feedback Input. If external feedback resistors are applied, the output

voltage will be :

) Volts

5

GND

Ground.

2

1

R

R

Function Block Diagram

OUT

R1

V

= 1.25 x (1+

) Volts

R2

VIN

GND

VOUT

RT9009

4.7uF

2.2uF

ADJ

EN

R1

R2

Chip Enable

1

2

3

4

5

EN

VIN

VOUT

ADJ

GND

Logic Control

POR/OCP/OTP

+

-

Driver