原标题：Linear LTM4650 50A降压μModuleR稳压电源方案

　　Linear公司的LTM4650是双路25A或单路50A开关模式降压DC/DC μModuleR(功率模块)稳压器.16mm × 16mm × 5.01mm BGA封装内集成了开关控制器,功率FET,电感和支持元件.输入电压4.5V-15V,输出电压0.6V-1.8V.主要用在处理器,ASIC和FPGA核电源,通信和网络设备,存储和ATCA卡以及工业设备.本文介绍了LTM4650主要特性,框图和几种典型应用电路,以及演示板DC2378A-A主要特性,电路图和材料清单.

　　The LTMR4650 is a dual 25A or single 50A output switchingmode step-down DC/DC μModuleR (power module)regulator. Included in the package are the switchingcontrollers, power FETs, inductors, and all supportingcomponents. Operating from an input voltage range of4.5V to 15V, the LTM4650 supports two outputs eachwith an output voltage range of 0.6V to 1.8V, each set by asingle external resistor. Its high efficiency design deliversup to 25A continuous current for each output. Only a fewinput and output capacitors are needed. The LTM4650 ispin compatible with the LTM4620 (dual 13A, single 26A)and the LTM4630 (dual 18A, single 36A).

　　The device supports frequency synchronization, multiphaseoperation, Burst Mode operation and output voltagetracking for supply rail sequencing and has an onboardtemperature diode for device temperature monitoring. Highswitching frequency and a current mode architecture enablea very fast transient response to line and load changes without sacrificing stability.Fault protection features include overvoltage andovercurrent protection. The LTM4650 is offered in a16mm × 16mm × 5.01mm BGA package.

　　LTM4650主要特性:

　　Dual 25A or Single 50A Output

　　Input Voltage Range: 4.5V to 15V

　　Output Voltage Range: 0.6V to 1.8V

　　±1.5% Maximum Total DC Output Error Over Line,Load and Temperature

　　Differential Remote Sense Amplifier

　　Current Mode Control/Fast Transient Response

　　Adjustable Switching Frequency

　　Frequency Synchronization

　　Overcurrent Foldback Protection

　　Multiphase Parallel Current Sharing with MultipleLTM4650s Up to 300A

　　Internal Temperature Monitor

　　Pin Compatible with the LTM4620(Dual 13A, Single26A)and LTM4630(Dual 18A, Single 36A)

　　Selectable Burst ModeR Operation

　　Soft-Start/Voltage Tracking

　　Output Overvoltage Protection

　　16mm × 16mm × 5.01mm BGA Package

　　LTM4650应用:

　　Processor, ASIC and FPGA Core Power

　　Telecom and Networking Equipment

　　Storage and ATCA Cards

　　Industrial Equipment

　　图1.LTM4650功能框图

　　图2.LTM4650应用电路:输入4.5VIN- 15VIN,输出1.5V和1.2V/25A

　　图3.LTM4650应用电路:2相,1V 50A

　　图4.LTM4650应用电路:1.2V和1V输出跟踪

　　图5.LTM4650应用电路:4相,1.2V 100A

　　演示板DC2378A-A

　　Demonstration circuit DC2378A-A features the LTMR4650EY,the high efficiency, high density, dual 25A, single 50A,switch mode step-down power module regulator. Theinput voltage is from 4.5V to 15V. The output voltage isprogrammable from 0.6V to 1.8V. DC2378A-A can deliver25A maximum current from each channel. As explainedin the data sheet, output current derating is necessaryfor certain VIN, VOUT, and thermal conditions. The boardoperates in continuous conduction mode in heavy loadconditions. For high efficiency at low load currents, theMODE jumper (JP1) selects pulse-skipping mode for noisesensitive applications or Burst ModeR operation in lessnoise sensitive applications. Two outputs can be connectedin parallel for a single 50A output solution with optionaljumper resistors.

　　The board allows the user to programhow its output ramps up and down through the TRACK/SS pin. The output can be set up to either coincidentally orratiometrically track with another supply’s output. Remoteoutput voltage sensing is available for improved outputvoltage regulation at the load point. These features andthe availability of the LTM4650EY in a compact 15mm ×15mm × 5.01mm BGA package make it ideal for use inmany high density point-of-load regulation applications.

　　The LTM4650 data sheet must be read in conjunction withthis demo manual for working on or modifying the democircuit DC2378A-A.

　　图6.演示板DC2378A-A外形图

　　演示板DC2378A-A材料清单: