基于SiC414設(shè)計的6A降壓電源穩(wěn)壓技術(shù)

SiC414集成了5V/200mA LDO的6A降壓電源穩(wěn)壓器,開關(guān)頻率高達1MHz,全部采用陶瓷電容.連續(xù)輸出電流達6A,效率大于95%,內(nèi)部軟起動和軟關(guān)斷,主要用在筆記本電腦,臺式電腦和服務(wù)器,數(shù)字HDTV和消費類電子,網(wǎng)絡(luò)和通信設(shè)備,打印機,DSL和STB,嵌入式應(yīng)用和點負(fù)載電源.本文介紹了SiC414主要特性, 功能方框圖, 典型應(yīng)用電路圖和SiC414評估板電路圖以及材料清單(BOM).

The Vishay Siliconix SiC414 is an advanced stand-alone synchronous buck regulator featuring integrated power MOSFETs, bootstrap diode, and an internal 5 V LDO in a space-saving MLPQ 4 x 4 - 28 pin package.

The SiC414 is capable of operating with all ceramic solutions and switching frequencies up to 1 MHz. The programmable frequency, synchronous operation and selectable power-save allow operation at high efficiency across the full range of load current. The internal LDO may be used to supply 5 V for the gate drive circuits or it may be bypassed with an external 5 V for optimum efficiency and used to drive external n-channel MOSFETs or other loads. Additional features include cycle-by-cycle current limit, voltage softstart, under-voltage protection, programmable over-current protection, soft shutdown and selectable power-save. The Vishay Siliconix SiC414 also provides an enable input and a power good output.

SiC414主要特性:

High efficiency > 95 %

6 A continuous output current capability

Integrated bootstrap switch

Integrated 5 V/200 mA LDO with bypass logic

Temperature compensated current limit

Pseudo fixed-frequency adaptive on-time control

All ceramic solution enabled

Programmable input UVLO threshold

Independent enable pin for switcher and LDO

Selectable ultra-sonic power-save mode

Internal soft-start and soft-shutdown

1 % internal reference voltage

Power good output and over voltage protection

Halogen-free according to IEC 61249-2-21 definition

Compliant to RoHS directive 2002/95/EC

SiC414應(yīng)用:

Notebook, desktop and server computers

Digital HDTV and digital consumer applications

Networking and telecommunication equipment

Printers, DSL and STB applications

Embedded applications

Point of load power supplies

圖1.SiC414功能方框圖

圖2.SiC414典型應(yīng)用電路圖