原标题：Linear LTC3880双输出多相降压电源解决方案

　　Linear公司的LTC3880/LTC3880-1是双输出多相DC/DC同步降压开关电源控制器,集成了基于I2C的PMBus兼容的串行接口,采用恒定频率电流模式架构.VIN输出电压从4.5V到24V,输出电压VOUT从0.5V到5.5V,输出电压对温度的变化为±0.5%.器件集成了15位ADC,主要用在大电流分布电源系统,通信,数据通信和存储器系统以及智能能效的电源系统.本文介绍了LTC3880/LTC3880-1主要特性,方框图, 三相工作负载共享连接图, 电感DCR和电阻电流检测电路图,以及多种应用电路图.

　　Dual Output PolyPhase Step-Down DC/DC Controller with Digital Power System Management

　　The LTC3880/LTC3880-1 are dual, PolyPhase DC/DC synchronous step-down switching regulator controllers with an I2C-based PMBus compliant serial interface. The controllers use a constant frequency, current mode architecture.

　　Switching frequency, output voltage, and device address can be programmed using external configuration resistors.

　　Additionally, parameters can be set via the digital interface or stored in EEPROM. Voltage, current, internal/external temperature and fault status can be read back through the bus interface.

　　The LTC3880/LTC3880-1 can be configured for Burst Mode operation, discontinuous (pulse-skipping) mode or continuous inductor current mode. The LTC3880 incorporates a 5V linear regulator while the LTC3880-1 uses an external 5V supply for minimum power loss.

　　The LTC3880/LTC3880-1 are available in a 40-pin 6mmx 6mm QFN package.

　　LTC3880/LTC3880-1主要特性:

　　PMBus/I2C Compliant Serial Interface

　　– Query Voltage, Currents, Temperature and Faults

　　– Programmable Voltage, Current Limit, Digital Soft-Start/Stop, Sequencing, Margining, OV/UV and Frequency Synchronization (250kHz to 1MHz)

　　±0.5% Output Voltage Accuracy over Temperature

　　Integrated 15-Bit ADC

　　Optional Resistor Programmable Parameters

　　Internal EEPROM and Fault Logging

　　Integrated Powerful N-Channel MOSFET Gate Drivers Power Conversion

　　Wide VIN Range: 4.5V to 24V

　　VOUT Range: 0.5V to 5.5V

　　Analog Current Mode Control Loop

　　Supports Power-Up Into Pre-Biased Load

　　Accurate PolyPhase Current Sharing for Up to 6 Phases

　　Available in a 40-Pin (6mmx6mm) QFN Package

　　LTC3880/LTC3880-1应用:

　　High Current Distributed Power Systems

　　Telecom, Datacom and Storage Systems

　　Intelligent Energy Efficient Power Regulation

　　图1.LTC3880/LTC3880-1方框图

　　图2.LTC3880/LTC3880-1三相工作负载共享连接图

　　图3.LTC3880/LTC3880-1电感DCR电流检测电路图

　　图4.LTC3880/LTC3880-1电阻电流检测电路图

　　图5.LTC3880/LTC3880-1推荐PCB布局图

　　图6.LTC3880高效双路500kHz 3.3V/1.8V降压转换器电路图

　　图7.LTC3880 LTC控制器连接图

　　图8.LTC3880高效双路425kHz 2.5V/1.8V降压转换器电路图

　　图9.LTC3880高效双路带检测电阻的500kHz 5V/3.3V降压转换器电路图

　　图10.LTC3880高效350kHz双相1.5V降压转换器电路图

　　图11.LTC3880高效450kHz 1.0V降压双相转换器电路图

　　图12.LTC3880高效三相450kHz 2.5V单个1.8V降压转换器电路图

　　图13.LTC3880高效四相425kHz 1.0V降压转换器电路图