AP2014/A

Synchronous PWM Controller

This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of this

product. No rights under any patent accompany the sale of the product.

Rev. 1.2 Nov 29, 2005

1/12

Features

- Synchronous Controller in 8-Pin Package

- Operating with single 5V or 12V supply voltage

- Internal 200KHz Oscillator (400KHz for AP2014A)

- Soft-Start Function

- Fixed Frequency Voltage Mode

- 500mA Peak Output Drive Capability

- Protects the output when control FET is shorted

- SOP-8L/PDIP-8L Pb-Free package

Applications

- Graphic Card

- Hard Disk Drive

- DDR memory source sink Vtt application

- Low cost on-board DC to DC such as 5V to 3.3V,

2.5V or 1.8V

Pin Assignments

SOP-8L/PDIP-8L

1

2

3

45

6

7

8

(Top View)

Vcc

GND

AP2014/A

LDrv

HDrv

Vc

Comp

FB

SS

General Description

The AP2014 controller IC is designed to provide a

low cost synchronous Buck regulator for on-board

DC to DC converter applications. With the migration

of today’s ASIC products requiring low supply

voltages such as 1.8V and lower, together with

currents in excess of 3A, traditional linear regulators

are simply too lossy to be used when input supply is

5V or even in some cases with 3.3V input supply.

The

AP2014

together

with

dual

N-channel

MOSFETs such as AF9410, provide a low cost

solution for such applications. This device features

an internal 200KHz oscillator (400KHz for "A"

version), under-voltage lockout for both Vcc and Vc

supplies,

an

external

programmable

soft-start

function as well as output under-voltage detection

that latches off the device when an output short is

detected.

Pin Descriptions

Pin

Name

Pin

No.

Description

FB

1

This pin is connected directly to the output of the

switching regulator via resistor divider to provide

feedback to the Error amplifier.

Vcc

2

This pin provides biasing for the internal blocks of

the IC as well as power for the low side driver. A

minimum of 1uF, high frequency capacitor must be

connected from this pin to ground to provide peak

drive current capability.

LDrv

3

Output driver for the synchronous power MOSFET.

GND

4

This pin serves as the ground pin and must be

connected directly to the ground plane. A high

frequency capacitor (0.1 to 1uF) must be connected

from V5 and V12 pins to this pin for noise free

operation.

HDrv

5

Output driver for the high side power MOSFET.

Vc

6

This pin is connected to a voltage that must be at

least 4V higher than the bus voltage of the switcher

(assuming 5V threshold MOSFET) and powers the

high side output driver. A minimum of 1uF, high

frequency capacitor must be connected from this

pin to ground to provide peak drive current

capability.

Comp

7

Compensation pin of the error amplifier. An external

resistor and capacitor network is typically connected

from

this

pin

to

ground

to

provide

loop

compensation.

SS

8

This pin provides soft-start for the switching

regulator. An internal current source charges an

external capacitor that is connected from this pin to

ground which ramps up the output of the switching

regulator, preventing it from overshooting as well as

limiting the input current. The converter can be

shutdown by pulling this pin below 0.5V.