IR公司的IR3477 SupIRBuck是容易使用的高效全集成DC/DC电压稳压器，可提供精确控制的15A输出电压，输入电压从3V到27V，输出电压从0.5V到12V，不需要补偿回路，在非常低输出电流时有极好的效率，可编程开关频率和蔼软起动，主要用在笔记电脑和台式计算机，消费类电子如STB，LCD，TV和打印机等，12V和24V分布电源，通用POL DC/DC转换器以及游戏机和图像卡等.本文介绍了IR3477主要特性，方框图，典型应用电路，演示板电路图和材料清单，以及IRDC3477评估板主要特性，电路图和材料清单.

 The IR3477 SupIRBuckTM is an easy‐to‐use， fully integrated and highly efficient DC/DC voltage regulator. The onboard constant on time hysteretic controller and MOSFETs make
IR3477 a space‐efficient solution that delivers up to 15A of precisely controlled output voltage.

 Programmable switching frequency， soft start， and thermally compensated over current protection allows for a very flexible solution suitable for many different applications and an ideal choice for battery powered applications.

 Additional features include pre‐bias startup， very precise 0.5V reference， under/over voltage shutdown， thermal protection， power good output， and enable input with voltage monitoring capability.

 IR3477主要特性:

Input Voltage Range: 3V to 27V

Output Voltage Range: 0.5V to 12V

Continuous 15A Load Capability

Constant On‐Time Control

Compensation Loop not Required

Excellent Efficiency at Very Low Output Currents

Programmable Switching Frequency and Soft Start

Thermally Compensated Over Current Protection

Power Good Output

Precision Voltage Reference (0.5V， +/‐1%)

Enable Input with Voltage Monitoring Capability

Pre‐bias Start Up

Thermal Shut Down

Under/Over Voltage Fault Protection

Forced Continuous Conduction Mode Option

Small， Low Profile 5mm x 6mm QFN Package

IR3477应用:

Notebook and Desktop Computers

Consumer Electronics – STB， LCD， TV， Printers

12V and 24V Distributed Power Systems

General Purpose POL DC‐DC Converters

Game Consoles and Graphics Cards

图1.IR3477功能方块图

图2.IR3477典型应用电路图

图3.IR3477演示板电路图: VOUT = 1.05V， FS = 300kHz

演示板材料清单(BOM)

IRDC3477评估板主要特性:

VIN = +12V

VCC = +5V

VOUT = +1.05V

IOUT = 0 to 15A

FS = 300kHz @ CCM

L = 1μH

CIN = 22μF (ceramic 1210) + 68μF (electrolytic)

COUT = 47μF (ceramic 0805) + 330μF (PC-CON)

图4.IRDC3477评估板外形和连接图

图5.IRDC3477评估板电路图

IRDC3477评估板材料清单(BOM)