RT9201

3

DS9201-12 August 2007

www.richtek.com

Function Block Diagram

Functional Pin Description

Pin No.

Pin Name

Pin Function

1

EN

Tie this pin to 1.4V or higher to enable the device. Tie below 0.4V to shut-down.

2

SS

Soft Start, connect a capacitor from this pin to GND.

3

FB

Feedback Input pin. Connect a resistive voltage divider from the output voltage to FB

to GND.

4, 10

NC

No Connection.

5

GND

Analog Ground.

6

PGND

Power Ground.

7

LX

Switch node. Drains of the internal P-Channel and N-Channel MOSFET switches.

Connect an inductor to LX pins together as close as possible.

8

PVDD

Main Power Supply Pin.

9

VDD

Device Input Power Pin.

Exposed Pad (11) GND

The exposed pad must be soldered to a large PCB and connected to GND for

maximum power dissipation.

OSC & Shutdown

Control

Current

Sense

Control

Logic

Zero

Detector

Driver

Slope

Compensation

V

REF

LX

EN

PVDD

PGND

FB

SS

VDD

GND

PWM

Comparator

0.8V

Error

Amplifier

300k

Ω

Component Supplier

Part No.

Capacitance (uF)

Case Size

C2012X5R0J106M

10

0805

TDK

C3225X5R0J226M

22

1210

ECJ2FB0J106M

10

0805

Panasonic

ECJHVB0J226M

22

1206

JMK212BJ106M

10

0805

JMK212BJ226MG

22

0805

TAIYO YUDEN

JMK316BJ226ML

22

1206