Linear LTM4601 12A电源评估方案

Linear公司的LTM4601是完整的12A降压开关模式DC/DC电源,集成了开关控制器,MOSFET,电感器和所有的支持元件.采用15mmx15mm x2.8mm LGA表面贴装封装.输入电压从4.5V到28V,输出电压从0.6V到5V,并具有输出电压跟踪功能,连续输出电流12A(峰值电流14A),广泛应用在通信和网络设备,服务器,工业设备和点负载稳压电源.本文介绍了LTM4601的主要特性,简化的功能方框图,典型应用电路以及各种输出电流电压的详细电路图.同时还介绍了LTM4601评估板DC1041A-A的主要特性,电路图以及所用的元件列表.

The LTM 4601HV is a complete 12A step-down switch mode DC/DC power supply with onboard switching controller, MOSFETs, inductor and all support components.

The μModule is housed in a small surface mount 15mmx15mm x2.8mm LGA package. Operating over an input voltage range of 4.5 to 28V, the LTM4601HV supports an output voltage range of 0.6V to 5V as well as output voltage tracking and margining. The high
efficiency design delivers 12A continuous current (14A peak). Only bulk input and output capacitors are needed to complete the design.
The low profile (2.8mm) and light weight (1.7g) package easily mounts in unused space on the back side of PC boards for high density point of load regulation. The μModule can be synchronized with an external clock for reducing undesirable frequency harmonics and allows PolyPhase® operation for high load currents.

A high switching frequency and adaptive on-time current mode architecture deliver a very fast transient response to line and load changes without sacrificing stability. An onboard differential remote sense amplifier can be used to accurately regulate an output voltage independent of load current.

主要特性:
Complete Switch Mode Power Supply
Wide Input Voltage Range: 4.5V to 28V
12A DC Typical, 14A Peak Output Current
0.6V to 5V Output Voltage
Output Voltage Tracking and Margining
Parallel Multiple μModulesTM for Current Sharing
Differential Remote Sensing for Precision Regulation
PLL Frequency Synchronization
±1.5% Regulation
Current Foldback Protection (Disabled at Start-Up)
Pb-Free (e4) RoHS Compliant Package with Gold Finish Pads
Ultrafast Transient Response
Current Mode Control
Up to 95% Efficiency at 5VIN, 3.3VOUT
Programmable Soft-Start
Output Overvoltage Protection
Small Footprint, Low Profile (15mm × 15mm ×2.8mm) Surface Mount LGA Package

应用:
Telecom and Networking Equipment
Servers
Industrial Equipment
Point of Load Regulation



图1.LTM4601简化的方框图



图2. LTM4601典型应用电路图



图3.不带差分放大器的5V 8A设计电路图



图4.3.3V 10A设计电路图



图5.输入22V-28V,输出1.5V 10A设计电路图(500kHz)



图6. 2相并联3.3V 20A设计电路图



图7.带跟踪的双输出(3.3V和2.5V)设计电路图



图8.带跟踪的双输出(1.8V和1.5V)设计电路图
LTM4601评估板DC1041A-A
Demonstration circuit DC1041A-A features the LTM®4601EV, the high efficiency, high density switch mode step-down power module. The input voltage range is from 4.5V to 20V. The output voltage is programmable from 0.6V to 5V, refer to step down ratio curve in the LTM4601 datasheet. The rated load current is 12A, while de-rating is necessary for certain VIN, VOUT, and thermal conditions. Integrated input and output filters enable a simple PCB layout. Only bulk input and output capacitors are needed externally. An internal phase-lock loop allows the Module to be synchronized to an external clock. The LTM4601 allows the user to program output ramp-up and ramp-down through the TRACK/SS pin.

The output can be set to coincidentally or ratiometrically track with another supply.s output. Margining function is provided for the user who wants to stress their system by varying supply voltages during testing; refer to datasheet for functional diagram.



图9. LTM4601评估板DC1041A-A电路图
下表为LTM4601评估板元件列表: