RT8032

2

DS8032-02

March 2011

www.richtek.com

Functional Pin Description

Pin No.

Pin Name

Pin Function

1

SHDN/SS

Shutdown and Soft-Start Control Input. Connect this pin to a supply voltage that is

>1.4V to enable the IC and to a supply voltage that is <0.4V to shutdown the IC. An

RC network from the shutdown command signal to the pin will provide a soft-start

function by the rising time of the FB pin

2, 7

NC

No Internal Connection.

3

GND

Ground. Return the feedback resistive dividers to this ground, which in turn

connects to PGND at one point.

4

SW

Internal Power MOSFET Switches Output. Connect this pin to the output inductor.

5,

13 (Exposed Pad)

PGND

Power Ground. The exposed pad must be soldered to a large PCB and connected

to PGND for maximum power dissipation.

6, 8

VOUT

9

VIN

Power Input. Internal VCC for the IC. A 10

μF ceramic capacitor is recommended

as close as to VIN and GND as possible

10

ISET

Average Input Current Limit Setting. Place a resistor and capacitor in parallel from

the pin to GND

11

COMP

Error Amplifier Output. The current comparator threshold increases with the control

voltage. Connect external compensation elements to the Pin to stabilize the control

loop.

12

FB

Feedback Input. Receives the feedback voltage from a resistive divider connected

across the output.

Typical Application Circuit

VIN

9

RT8032

3

PGND

SW

4

COMP

FB

12

11

GND

5, Exposed Pad (13)

10µF

L

4.7µH

R1

112k

R2

32k

120k

60nF

1 SHDN/SS

10

ISET

24k

680nF

1k

2200nF

VOUT 6, 8

1.1nF

1Meg

57nF

3.6V