5

SC220

Pin Descriptions

Pin #

Pin Name

Pin Function

1

SW

Switching output node — connect to the output LC filter.

2

PVIN

Power input supply voltage (2.7V to 5.5V).

3

VOUT

Input for sensing the output of LC filter.

4FB

Input for regulation of output LC filter — Using R

1

and R

2

to set the output voltage, V

OUT

= V

FB

x (1+ R

1

/R

2

). (Please refer

to the typical application circuit diagram on page 1).

5EN

Enable Input — when low, circuit draws <1μA. Apply a square wave clock at EN to synchronize the switching frequency

with an external clock. It is recommended that the externally applied clock frequency should not be above 20MHz.

6AVIN

Input supply voltage.

7

AGND

Analog ground.

8

PGND

Power ground.

Block Diagram

SW

PG N D

EN

AVIN

PVIN

FB

6

AG N D

8

4

1

7

3

2

5

VO U T

CLIM

C om pens ator

C ontrol Logic

ZC D

+

-

1.0V

+

-

Frequenc y

Control

Soft-S tart

Therm al

S hutdow n

RE F

1.0V

OS C

20 M H z

Driv er

E x ternal Freq .

S y nc hroniz ation

Com p

E rror

Am p