Linear LTM4607高效降－升压模式开关电源解决方案

2012年06月11日 11:58 发布者：1770309616

Linear公司的LTM4607是高效(高达98%)开关模式降-升压模式电源,集成了开关控制器,功率FET和支持的元件,输入电压4.5V到36V,输出电压0.8V到24V由外接电阻设定.升压模式输出电流高达5A,降压模式输出电流高达10A,主要用在通信,服务器和网络设备,工业和自动化设备,大功率以电池为能源的设备.本文介绍了LTM4607主要特性,框图,多种应用电路以及演示板DC1601B主要特性,电路图以及材料清单.

The LTM.4607 is a high efficiency switching mode buckboost power supply. Included in the package are the switching controller, power FETs, and support components.

Operating over an input voltage range of 4.5V to 36V, the LTM4607 supports an output voltage range of 0.8V to 24V, set by a resistor. This high efficiency design delivers up to 5A continuous current in boost mode (10A in buck mode). Only the inductor, sense resistor, bulk input and output capacitors are needed to finish the design.

The low profile package enables utilization of unused space on the bottom of PC boards for high density point of load regulation. The high switching frequency and current mode architecture enable a very fast transient response to line and load changes without sacrificing stability. The LTM4607 can be frequency synchronized with an external clock to reduce undesirable frequency harmonics.

Fault protection features include overvoltage and foldback current protection. The DC/DC μModule. regulator is offered in a small thermally enhanced 15mmx15mmx2.8mm LGA package. The LTM4607 is Pb-free and RoHS compliant.

LTM4607主要特性:

Single Inductor Architecture Allows VIN Above, Below or Equal to VOUT

Wide VIN Range: 4.5V to 36V

Wide VOUT Range: 0.8V to 24V

5A DC (10A DC in Buck Mode)

High Efficiency Up to 98%

Current Mode Control

Power Good Output Signal

Phase-Lockable Fixed Frequency: 200kHz to 400kHz

Ultrafast Transient Response

Current Foldback Protection

Output Overvoltage Protection

Small, Low Profile Surface Mount LGA Package (15mm x15mmx2.8mm)

LTM4607应用:

Telecom, Servers and Networking Equipment

Industrial and Automotive Equipment

High Power Battery-Operated Devices

图1.LTM4607简化框图

图2.LTM4607输入12V-36V降压模式应用电路

图3.LTM4607输入5V-12V升压模式低开关噪音应用电路

图4.LTM4607输入5V-36V输出12V/5A宽输入模式应用电路

图5.LTM4607 5V/10A设计电路

图6.LTM4607两相并联12V/10A设计电路

图7.LTM4607降压模式正到负-12V输出设计电路

演示板DC1601B

Demonstration circuit DC1601B is a PolyPhase. power supply featuring the LTM.4607 power module, a complete high efficiency switching mode buck-boost power supply.

The DC1601B input voltage range is from 6V to 36V and is capable of delivering high power through paralleled LTM4607 modules. The demo circuit can deliver up to 10A of output current for two paralleled modules (DC1601B-A), 15A for three paralleled modules (DC1601B-B) and up to 20A for four paralleled modules (DC1601B-C). The DC1601B demonstrates that paralleling modules is easy and reliable.

The output voltage for the board is 12V. The rated load current per module is 5A in boost mode, however current derating may be necessary under certain VIN, VOUT, frequency, and thermal conditions. An onboard external clock is provided for synchronization and interleaving of L, LT, LTC, LTM, Linear Technology, PolyPhase and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.

phases to minimize input and output ripple. An internal phase-locked loop allows the LTM4607 to be synchronized to an external clock within the range of 200kHz to 400kHz. The LTM4607 default switching frequency on the DC1601B is set to 300kHz through the onboard LTC6902 clock generator which interleaves the paralleled phases.

The frequency and phase separation set by the LTC6902 are resistor programmable.

These features, including the availability of the LTM4607 in a compact thermally enhanced 15mmx15mmx2.8mm LGA package make the demonstration circuit ideal for use in high density point of load regulation applications.