原标题：Maxim MAX17558 60V双输出同步降压转换方案

　　Maxim公司的MAX17558是60V双输出同步降压控制器,驱动N-MOSFET,采用峰值电流模式,恒频架构,工作频率高达2.2MHz,可配置两路单相输出,每路10A,或配置双路单输出20A,工作温度-40℃到+125℃,输入电压4.5V 到 60V,输出电压0.8V到24V,主要用在工业电源,分布DC电源,运动控制,PLC和计算数字控制.本文介绍了MAX17558优势和主要特性,框图,几种应用电路以及MAX17558双相评估板主要特性,电路图,材料清单和PCB设计图.

　　The MAX17558 is a dual-output, synchronous step-down controller that drives nMOSFETs.

　　The device features a peak-current-mode, constant-frequency architecture, allowing it to operate up to 2.2MHz. The device can be configured as two single-phase, independent 10A power supplies or as a dual-phase, single-output 20A power supply. The device also provides the ability to run two controllers 180° out-of-phase to reduce the power loss and noise due to the input-capacitor ESR.

　　The IC supports current sensing using either an external current-sense resistor for accuracy or an inductor DCR for improved system efficiency. Current foldback limits MOSFET power dissipation under short-circuit conditions.

　　The IC provides independent adjustable soft-start for each output and can start up monotonically into a prebiased output. The IC can be configured in either PWM or DCM modes of operation, depending on whether constant-frequency operation or light-load efficiency is desired.

　　The IC operates over the -40℃ to +125℃ temperature range and is available in a lead(Pb)-free, 32-pin TQFN, 5mm x 5mm package with an exposed pad.

　　MAX17558优势和主要特性:

　　Wide Range of Operation

　　• Wide 4.5V to 60V Input Voltage Range

　　• Wide 0.8V to 24V Output Voltage Range

　　• RSENSE or Inductor DCR Current Sensing

　　• Selectable In-Phase or 180°Out-of-Phase Operation

　　• Adjustable 100kHz to 2.2MHz Switching Frequency

　　• Independent Enable and PGOOD

　　• Available in a Lead(Pb)-Free 32-Pin, 5mm x 5mm TQFN-EP Package

　　Enhances Power Efficiency

　　• Low-Impedance Gate Drives for High Efficiency

　　• DCM Operation at Light Loads

　　• Auxiliary Bootstrap LDO

　　Operates Reliably in Adverse Industrial Environments

　　• Independent Adjustable Soft-Start or Tracking

　　• Current Foldback Limits MOSFET Heat Dissipation During a Short-Circuit Condition

　　• Operates Over the -40℃ to +125℃ Temperature Range

　　• Output Overvoltage and Overtemperature Protections

　　MAX17558应用:

　　Industrial Power Supplies

　　Distributed DC Power Systems

　　Motion Control

　　Programmable Logic Controllers

　　Computerized Numerical Control

　　图1.MAX17558框图

　　图2. MAX17558应用电路:宽输入高效5V和3.3V输出降压转换器,电阻电流检测(R8,R9)

　　图3. MAX17558应用电路:宽输入高效5V和3.3V输出降压转换器,电感DCR电流检测(L1,L2)

　　图3. MAX17558应用电路:宽输入高效双相3.3V/20A输出降压转换器,电流检测

　　MAX17558双相评估板

　　The MAX17558 dual-phase EV kit provides a provendesign to evaluate the MAX17558 wide 4.5V to 60V input,dual-phase, synchronous step-down DC-DC controller. In2-phase operation, the two channels of the MAX17558are operated 180° out of phase. This interleaves thecurrent pulses drawn by the 2 phases, and results inreduced total RMS input current, which allows use oflesser number of input capacitors. The EV kit provides

　　3.3V/20A at the outputs from a 6V to 54V input supply.

　　The switching frequency of the EV kit is preset to 350kHzfor optimal efficiency and component size. The EV kit featuresadjustable input undervoltage-lockout and soft-start time,selectable PWM/DCM modes, 180°out-of-phase/0° inphaseoperation, current-limit threshold, and independentopen-drain PGOOD signals.

　　MAX17558双相评估板主要特性:

　　●● 6V to 54V Input Range

　　●● Output Rails: VOUT: 3.3V/20A

　　●● 350kHz Switching Frequency

　　●● Independent Enable Inputs

　　●● Independent Adjustable Soft-Start Time

　　●● Configurable Tracking Operation

　　●● Selectable PWM/DCM Modes of Operation

　　●● Selectable 180° Out-of-Phase/0° In-Phase Operation

　　●● Selectable Current-Limit Threshold

　　●● Independent PGOOD Outputs

　　●● Overcurrent, Overvoltage, and OvertemperatureProtection

　　●● Proven PCB Layout

　　●● Fully Assembled and Tested

　　图4.MAX17558双相评估板电路图

　　MAX17558双相评估板材料清单: