AT1367A/B/C/D

Preliminary Product Information

1MHz, 800mA Synchronous Buck Converter

With Power Good Detector & LDO

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878

Fax: 886-3-563-0879

3/2/2006

REV:1.2

1

Features

• Operation Voltage 2.5V~6.0V

• Oscillation frequency 1MHz

• Output Current Maximum 800mA（DC-DC

Converter）

• Built-In 400mA/LDO

• Power Good Indicator with Time Delay

Adjustable

• Built-In Current Limit

• Built-In UVLO

• Built-In Thermal ShutDown

Applications

• Power Supply for Slim Type devices

General Description

The AT1367A/B/C/D provides complete

control for a DC/DC converter optimized for

hight-performance microprocessor applications. It

consists of a synchronous step-down DC/DC

converter and a high-speed LDO regulator

connected in series with the DC/DC converter

output. A power good detector and LDO ON/OFF

control is also built-in(metal option). DC/DC

converter is operated on current mode architecture

for excellent line and load transient response.

1MHz operation frequency is allowing the use of

small surface mount inductor and capacitor. The

internal synchronous switch increases efficiency

and eliminates the need for an external schottky

diode. The AT1367A/B/C/D is a family of

low-noise

synchronous

step-down

DC/DC

converters that is ideally suited for systems

powered form a 1-cell Li-ion battery or from a

3-cell to 4-cell NiCd, NiMH, or alkaline battery. It

can also be used to USB-based power system.

Block Diagram

Current

Sense

OSC

+

SLOPE

R

S

Q

SW

Vref

+

-

/PG

VCC

PGND

Shoot

Throught

PG

DELAY

OUT2

OUT1

+

-

Vref

Current

Limit

5

UVLO

VREG

Vref

-

+

Vref

R2

R1

UVLO

*OUT2=2.5V/1.8V

Metal Option

CTL

Control

LDO

CTL

CTL

Auto

Discharge

VCC

0.9 x

Vref

R4

R3

*CTL and /PG

Metal Option

0.35uA

R5

VBG

VBG

AGND

+

-

Aimtron reserves the right without notice to change this circuitry and specifications.