RT8078A

3

DS8078A-01 June 2011

www.richtek.com

Function Block Diagram

Pin No.

WDFN-10L 3x3

SOP-8

(Exposed Pad)

Pin

Name

Pin Function

1, 2, 3

1, 2

LX

Switch Node. Connect this pin to the inductor.

4

3

PGOOD

Power Good Indicator. This pin is an open drain logic output that is

pulled to ground when the output voltage is less than 90% of the

target output voltage. Hysteresis = 5%.

5

4

EN

Enable Control. Pull high to turn on. Do not float.

6

5

FB

Feedback Pin. This pin receives the feedback voltage from a

resistive voltage divider connected across the output.

7

--

NC

No Internal Connection.

8

6

SVIN

Signal Input Pin. Decouple this pin to GND with at least 1

μF ceramic

cap.

9,10

7,8

PVIN

Power Input Pin. Decouple this pin to GND with at least 4.7

μF

ceramic cap.

11

(Exposed Pad)

9

(Exposed Pad)

GND

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

connected to GND for maximum power dissipation.

Functional Pin Description

Driver

NISEN

Control

Logic

Zero Current

0.72V

0.54V

0.2V

OC

Limit

ISEN

Slope

Com

OSC

Output

Clamp

EA

0.6V

Int-SS

POR

OTP

EN

FB

PVIN

SVIN

EN

LX

PGOOD

PGOOD

OV

PG

UV