Block Diagram

2

Pin Configuration & Marking Information

Top View

SOT23 5

-

CG: Product Code

of PAM2312

V:

Output Voltage

Y:

Year

W: Week

X:

Internal Code

,

Power Analog Microelectronics Inc

www.poweranalog.com

PAM2312

1A Step-Down DC-DC Converter

Name

F unction

VIN

Chip main power supply pin

GND

Ground

EN

Enable control input. Forc e this pin voltage above 1.5V, enables the chip, and below

0.3V shuts down the device.

VOUT/FB

VOUT: Output voltage feedback pin, an internal resis tive divider divides the output

voltage down for comparison to the internal reference voltage.

FB: Feedback voltage to internal error amplifier, the threshold voltage is 0.6V.

SW

The drains of the internal main and synchronous power MOSFET.

1

2

3

5

4

EN

GND

SW

VOUT/FB

VIN

Pin Description

EN

R1

R2

VOUT/FB

+

-

IAMP

+

-

IRCMP

SW

GND

SYNCHRONOUS

RECTIFIER NCH

(

)

MAIN

SWITCH PCH

(

)

VIN

COMP

VIN

SHUTDOWN

OSC

RS LATCH

0.6VREF

FREQ

SHIFT

-

+

EA

S Q

R Q

SWITCHING

LOGIC

AND

BLANKING

CIRCUIT

SLOPE

COMP

1.5M

OSC

ANTI

SHOOT

THRU

-

-

05/2010 Rev1.0