原标题：Renesas ISL68301PMBus兼容单相数字DC-DC控制方案

　　Renesas公司的ISl68301 是用于SPS和DrMOS功率级的PMBus兼容的单相数字DC/DC控制器,支持广泛的故障管理系统,采用专有硬件支持逐个周期过流,过压,欠压和温度故障.具有独到的无补偿设计,经常是稳定的,输入电压范围:4.75V-16V或4.5V-5.5V,输出电压0.45V-5.5V,输出电压精度 0.5%,开关频率200kHz到1.0MHz,主要用在服务器和存储设备,通信和数据通信设备,以及如FPGA,ASIC,DSP和存储器电源.本文介绍了ISL68301主要特性,框图,几种应用电路,以及评估板ISL68301EVAL2Z主要特性和指标,电路图,材料清单和PCB设计图.

　　The ISL68301 is a PMBus compliant, single-phasedigital DC/DC controller for use with SPS and DrMOSpower stages.

　　The ISL68301 implements the Renesas fully digitalChargeMode™ control modulation scheme, allowing itto achieve both industry leading performance and ease ofuse. ChargeMode control provides an inherently stablecontrol loop that can respond to load transients in a singleswitching cycle, significantly decreasing output capacitorrequirements.

　　A dedicated current share bus allows for paralleling up toeight devices in a current share configuration, allowingsupport for a wide range of load currents.In conjunction with many other Renesas digitalcontrollers, the ISL68301 is capable of complexsequencing and fault spreading. The Digital-DC™(DDC) bus is a single-wire serial bus which provideshigh performance inter-device communication withoutthe need for external sequencers, reducing overall systemcosts.

　　The PMBus interface facilitates device configuration,provides supply telemetry and detailed fault reportingincluding a parametric capture tool (SnapShot). All ofthese features are conveniently accessible through thePowerNavigator™ software tool. Additionally, a widearray of common configuration options areindependently configurable through use of pin-strapresistors.

　　The ISL68301 supports a comprehensive faultmanagement system, with dedicated hardware supportfor cycle-by-cycle overcurrent, overvoltage,undervoltage, and temperature faults. The configurablefault response system is capable of latching off orrestarting the output on a fault-by-fault basis. IntegratedLDOs for device and gate driver bias allow for singlesupply operation.

　　The ISL68301 drives a PWM output designed to bepaired with the Renesas family of Smart Power powerstages.A companion device, the ISL68300, has built-inMOSFET driver circuitry which supports use withdiscrete output MOSFETs.

　　ISL68301主要特性:

　　• Unique compensation-free design, which is alwaysstable

　　• Output voltage range: 0.45V to 5.5V

　　• Input voltage range: 4.75V to 16V or 4.5V to 5.5V

　　• 0.5% output voltage accuracy over line, load, andtemperature

　　• ChargeMode control achieves fast transient response,requires minIMAl output capacitance, and providesoutput stability without compensation

　　• Single-channel output, can be paralleled with up toeight devices in a single droop-less current sharingoutput

　　• Switching frequency range of 200kHz to 1.0MHz

　　• Proprietary single-wire DDC serial bus enablesvoltage sequencing and fault spreading with otherRenesas digital power ICs

　　• Cycle-by-cycle inductor peak current protection

　　• Configurable fault protection for output voltageUV/OV, input voltage UV/OV, internal and SPStemperature

　　• Cycle-by-cycle output current measurement withadjustable gain settings for sensing with SPS currentmonitor or low DCR inductors

　　• Dedicated telemetry ADC monitors input voltage,input current, output voltage, internal temperature,and power stage temperature

　　• Nonvolatile memory (NVRAM) stores operatingparameters and fault events across POR cycles

　　• PMBus compliant. Supports 113 PMBus commands

　　• Compatible with Smart Power Stage (SPS) devices

　　ISL68301应用:

　　• Servers and storage equipment

　　• Telecom and datacom equipment

　　• Power supplies (FPGA, ASIC, DSP, memory)

　　图1.ISL68301框图

　　图2.ISL68301宽范围输入和输出应用电路图

　　图3.ISL68301和ISL99227B组成SPS(智能功率级)电路图

　　图4.ISL68301和ISL99227B的5V正常输入电路图

　　图5.ISL68301两相电流共享电路图

　　评估板ISL68301EVAL2Z

　　The ISL68301EVAL2Z evaluation board is a 2.7inx3.0in 6-layer FR4 board with 2oz. copper on all layers. Thisevaluation board comes with a placeholder for pin-strap resistors to adjust output voltage, switching frequency,faultresponse, current limit threshold and ASCR gain, and the device PMBus address. More configurations, such as soft-start and fault limits, can be easily programmed or changed using a PMBus compliant serial bus interface.

　　This evaluation board includes the ZLUSBEVAL3Z (USB to PMBus adapter), which connects the evaluation board toa PC to activate the PMBus communication interface. The PMBus command set is accessed by using thePowerNavigator™ evaluation software from a PC running Microsoft Windows.

　　图6.评估板ISL68301EVAL2Z外形图(顶视)

　　图7.评估板ISL68301EVAL2Z外形图(底视)

　　评估板ISL68301EVAL2Z主要特性:

　　• VIN range of 4.5V to 16V, VOUT adjustable from 2.5V to 5.5V

　　• Programmable VOUT, margining, UV/OV, IOUT limit, soft-start/stop, sequencing, and external synchronization

　　• Monitor: VIN, VOUT, IOUT, temperature, duty cycle, switching frequency, and faults

　　• ChargeMode control tunable with PMBus

　　• On-board load step circuit

　　• Mechanical switch for enable and power-good LED indicator

　　评估板ISL68301EVAL2Z主要指标:

　　This board is configured for the following operating conditions by default:

　　• VIN = 7V to 16V

　　• VOUT = 3.3V

　　• IMAX = 20A

　　• fSW = 500kHz

　　• Peak efficiency: >94% at 50% load

　　• On/off delay = 5ms, On/off ramp time = 5ms

　　图8.评估板ISL68301EVAL2Z框图

评估板ISL68301EVAL2Z材料清单: