Copyright

© ANPEC Electronics Corp.

Rev. A.4 - Oct., 2010

APW7199

www.anpec.com.tw

1

ANPEC reserves the right to make changes to improve reliability or manufacturability without notice, and

advise customers to obtain the latest version of relevant information to verify before placing orders.

High-Performance Step-Down PWM Controller with PFM

Features

•

Operates from An Input Battery Voltage Range of

+3V to +25V

•

±0.6% 0.5V Reference

- Over Line, Load Regulation, and Operating Temp.

•

Drive Dual Low Cost N-Channel MOSFETs

- Adaptive Shoot-Through Protection

•

Power-On-Reset Monitoring on VCC Pin

•

PFM Mode for Increasing Light Load Efficiency

•

Constant-On-Time Control Scheme

- Switching Frequency Compensation for PWM

Operation

•

300kHz Constant Switching Frequency

•

Integrated MOSFET Drivers and Bootstrap Diode

•

Internal Soft-Start and Soft-Stop

•

Power Good Monitoring

•

70% Under-Voltage Protection

•

125% Over-Voltage Protection

- Using Low-Side MOSFET’s R

DS(ON)

•

Over-Temperature Protection

•

TDFN-10 3mmx3mm Package

•

Lead Free and Green Devices Available

(RoHS Compliant)

General Description

Applications

•

Notebook

•

Low Cost PC

The APW7199 is a single-phase, constant-on-time, and

synchronous PWM controller, which drives N-channel

MOSFETs. An internal 0.5V temperature-compensated

reference voltage with high accuracy is designed to meet

the requirement of low output voltage applications. The

APW7199 steps down high voltage to generate low-volt-

age chipset or RAM supplies in notebook computers.

The PWM controller operates fixed 300kHz pseudo-con-

stant frequency PWM with an adaptive constant-on-time

control. The device provides excellent transient response

and accurate DC voltage output in either PFM or PWM

Mode. In Pulse Frequency Mode (PFM), the APW7199 pro-

vides very high efficiency over light to heavy loads with

loading-modulated switching frequencies. The device

works in ultrasonic mode with PFM at no load. The unique

ultrasonic mode maintains the switching frequency above

20kHz, which eliminates noise in audio applications.

output under-voltage, and output over-voltage protections.

A Power-On-Reset function monitors the voltage on VCC

to prevent wrong operation during power-on. The

APW7199 has a 1.5ms digital soft-start to ramp up the

output voltage to reduce the start-up current. A soft-stop

function actively discharges the output capacitors with

controlled reverse inductor current.

The APW7199 is available in TDFN3x3-10 package.

Simplified Application Circuit

V

OUT

L

OUT

Q2

EN/EXTREF

APW7199

V

IN

5V

Q1

C

OUT

R

OCSET

UGATE

PHASE

LGATE/OCSET

POK

BOOT

VCC