Linear 公司的LTM4609 是98%高效率的升降压开关电源，集成了开关控制器，功率FET和支持元件。输入电压从4.5V到36V，输出电压从0.8V到34V。升压模式可提供4A电流，而降压模式则可提供10A电流，效率高达98%。可锁相的固定频率从200kHz 到 400kHz，具有超快的瞬态响应特性。可用在电信，服务器和网络设备，工业和自动化设备以及大功率以电池为能源的设备。本文介绍了LTM4609的主要特性，方框图以及多种应用电路，包括12V-36V输入降压模式电路图，开关噪音低的5V-12V输入降压模式电路图，5-36V输入，12V 4A输出电路图以及两相并联，12V 8A电路图。

The LTM 4609 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 LTM4609 supports an output voltage range of 0.8V to 34V, set by a resistor. This high efficiency design delivers up to 4A continuous current in boost mode (10A in buckmode). Only the inductor, sense resistor, bulk input and output capacitors are needed to finish the design.

The low profi le 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 sacrifi cing stability. The LTM4609 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™ is offered in a small thermally enhanced 15mm × 15mm × 2.8mm LGA package. The LTM4609 is Pb-free and RoHS compliant.

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 34V
IOUT: 4A DC (10A DC in Buck Mode)
Up to 98% Efficiency
Current Mode Control
Power Good Output Signal
Phase-Lockable Fixed Frequency: 200kHz to 400kHz
Ultra-Fast Transient Response
Current Foldback Protection
Output Overvoltage Protection
Small, Low Profile Surface Mount LGA Package (15mm × 15mm × 2.8mm)

应用：
Telecom, Servers and Networking Equipment
Industrial and Automotive Equipment
High Power Battery-Operated Devices



图1。LTM4609简化功能图
典型应用电路图：



图2。12V-36V输入降压模式电路图



图3。开关噪音低的5V-12V输入降压模式电路图



图4。宽输入模式，5-36V输入，12V 4A输出电路图



图5。32V  2A 设计电路图



图6。两相并联，12V 8A电路图