原标题：Maxim MAX20796两相PMBus接口可升级电压稳压器解决方案

　　Maxim公司的MAX20796是全集成高效率两相开关稳压器,工作电压从4.5V到16V,负载电流高达60A,外接功率级三相可达90A.通过占空比的某些限制输出电压可配置在0.5V至5.5V.开关稳压器采用固定频率控制方案,具有极紧凑快速和精确的服务器和通信应用的供电解决方案.集成的线性稳压器允许使用单电源工作.为了进一步提高系统效率和热性能,外接3.3V电源或FET用来产生核电源.主要的系统参数可以通过外接电阻进行配置,包括选择软起动时序,输出电压,开关频率, PMBus地址,过电流跳闸点和回路控制参数.器件可工作在耦合电感或分立电感,而耦合电感技术提供高性能与最低数量的输入和输出电容.在VIN = 12V, VOUT = 1V时峰值效率为92%,满负载效率为90%.器件工作结温-40C至125C,封装为35引脚4 ×10.5mm, 0.5mm点距的FC2QFN封装.主要用在点负载电压稳压器,通信,网络,服务器和存储设备,微处理器芯片组和存储器VDDQ以及I/O和辅助电源.本文介绍了MAX20796主要优势和特性,框图,多种应用电路,以及评估板MAX20796 EVK主要特性,电路图,材料清单和PCB设计图.

　　The MAX20796 offers a fully integrated, highly efficient, two-phase switching regulator for applications operating from 4.5V to 16V and requiring up to 60A maximum load or 90A with an optional third-phase external power stage. The output voltage range can be configured from 0.5V to 5.5V with some restrictions on duty cycle. The switching regulator uses a fixed-frequency control scheme providing an extremely compact, fast, and accurate power delivery solution for server and telecom applications. Integrated linear regulators allow single-supply operation. To further improve system efficiency and thermal performance, an external 3.3V supply or FET can be used to generate the core supply.

　　Key system parameters are configured by external resistors, including the selection of soft-start timing, output voltage, switching frequency, PMBus address, overcurrent trip point, and loop control parameters. The device operates with either coupled or discrete inductors. Coupled induc­tor technology offers high performance with a minimum number of input and output capacitors for best-in-class solution cost.

　　The MAX20796 includes fault protection and reporting capabilities. Inherent positive and negative overcurrent and overtemperature protection ensure a rugged design. Input undervoltage lockout shuts down the device when the input voltage is out of specification. Regulation is halted if the output voltage is outside of a programmable range. A PGOOD pin provides an output signal to show that the output voltage is within range and the system is regulating.

　　The MAX20796 is offered in a 35-pin, 4 × 10.5mm FC2QFN package, ideal for use in networking and communication end equipment.

　　The device is also available as MAX20796A, which is preconfigured for a 1V, 800kHz application with LEAD_LAG enabled.

　　MAX20796主要优势和特性:

　　Peak Efficiency 92%; Full-Load Efficiency 90% atVIN = 12V, VOUT = 1V

　　Operating Input Voltage Range 4.5V to 16V

　　Output Voltage Range is 0.5V to 5.5V

　　Output Boot Voltage Pin-Strapped Range 0.5V to 5.0V with Direct Feedback

　　Integrated Loop Compensation

　　Supports Coupled and Discrete Inductors

　　PMBus Revision 1.3 Compliant Interface

　　Supports External Power Stage to Increase Power Capacity

　　Internal Linear Regulators Allow Operation from One Supply Voltage

　　Optional External LDO FET for Enhanced Thermal Performance

　　Pin-Strapped Configurable Operating Parameters:32 PMBus Addresses

　　Output Voltage

　　Switching Frequency

　　Overcurrent Protection (OCP) Threshold

　　Soft-Start Time

　　Loop Compensation

　　Continuous Conduction Mode Operation Only

　　Integrated Accurate Current and Temperature Sensing

　　Monotonic Startup and Shutdown, Supports Prebias Startup (Two-Phase)

　　Fast Peak and Average Overcurrent Protection

　　RESTORE Input Pin Resets Output Voltage

　　Operating Junction Temperature Range: -40Cto 125C

　　Package: 35-pin, 4 ×10.5mm, 0.5mm pitch, FC2QFN

　　MAX20796应用:

　　Point-of-Load Voltage Regulators

　　Communication, Networking, Servers and Storage Equipment

　　Microprocessor Chipsets

　　Memory VDDQ

　　I/O and Auxiliary Power

　　图1. MAX20796框图

　　图2. MAX20796简便应用电路图

　　图3. MAX20796应用电路图(1)

　　图4. MAX20796应用电路图(2)

　　图5. MAX20796应用电路图(3)

　　分立电感评估板MAX20796 EVK

　　The MAX20796 Discrete Inductor evaluation kit (EV kit) provides a proven design to evaluate the MAX20796 fully integrated, two-phase switching regulator. The MAX20766

　　can be installed on the EV kit for a three-phase switching regulator operation. The EV kit operates from a 4.5V to 16V input voltage range and supports an output voltage range of 1.8V to 5V. The board uses the MAX20796 on a proven eight-layer PCB design.

　　The MAX20796 Discrete Inductor EV kit provides a proven design to evaluate the MAX20796, fully integrated, highly efficient, two-phase switching regulator. MAX20766 can be installed on the EV kit for a three-phase switching regulator operation. The power input and load can be easily connected using the banana jacks and connectors provided

　　for the input and output. Test points and connectors are provided to monitor and control the device signals. The EV kit operates between input voltage of 4.5V to 16V.

　　The EV kit regulates the output voltage between 1.8V to 5V. The EV kit must always be operated within SOA limit defined in MAX20796 data sheet.

　　评估板MAX20796 EVK主要特性:

　　●● 4.5V to 16V Input Voltage Range

　　●● 1.8V to 5V Output Voltage Range

　　●● Banana Jacks for Input and Output Voltage

　　●● SMB Coaxial Cable Jacks for Output Voltage Measurement and SYNC Clock Input and Output

　　●● Configurable Output Voltage and Compensation Parameters

　　●● Adjustable Current Limit

　　●● PMBus Header for Connection to the MAXPOWERTOOL002# Dongle

　　●● FAULT and PG Outputs

　　●● Enable Input and Enable Debounce Circuit

　　●● Fully Assembled and Tested

　　图6. 评估板MAX20796 EVK外形图

　　图7. 评估板MAX20796 EVK电路图(1)

　　图8. 评估板MAX20796 EVK电路图(2)

　　图9. 评估板MAX20796 EVK电路图(3)

　　图10. 评估板MAX20796 EVK电路图(4)

　　图11. 评估板MAX20796 EVK电路图(5)