DUAL CHANNEL1.5 MHZ, 600MA SYNCHRONOUS STEP-DOWN CONVERTER

2007-7-11

2/10

FSP3112

PIN DESCRIPTION

BLOCK DIAGRAM

Pin Number

Pin Name

Pin Function

1

VFB1

Channel 1 output feedback. It receives the feedback voltage from the

external resistive divider across the output.

2

RUN1

Channel 1 Enable

3

VIN

Power Supply

4

SW1

Channel 1 power switch output

5

GND

Ground

6

NC

No Connection

7

SW2

Channel 2 power switch output.

8

POR

Power On Reset.

9

RUN2

Enable Pin of Channel 2.

10

VFB2

Channel 2 output feedback. It receives the feedback voltage from the

external resistive divider across the output.

11

EXPOSED PAD

Power Ground. It must be connect to ground properly.

8

Regulator 1

+

-

VFB2

_Q

600mV

ICOMP

PWM

7

SLOPE.COMP

Q

S

10

REFERENCE

BANDGAP

3

R

ICMP

RUN1

LOGIC

650mV

COUNTER

EA

OVDET

SW1

POR

ISENCE

+

-

+

-

1

9

VFB1

2

4

POR

VIN

RUN2

+

-

SW2

+

-

OSC

REGULATOR 2(The same structure as regulator 1)