原标题：ADI ADP1074隔离式DC-DC同步电源设计方案

　　ADI公司的ADP1074是集成有源钳位和iCoupler®的隔离式同步正向控制器,集成了ADI公司的专有iCouplers,在原边和副边均集成了隔离器和MOSFET驱动器,从而降低了系统设计复杂性,成本和元器件数量,并提高了系统的整体可靠性.此外还具有输入电流保护,欠压闭锁(UVLO),带可调迟滞功能的精密使能和过温保护(OTP)等特性,主要用在隔离式DC/DC电源转换,中间总线电压生成,电信和工业,基站和天线RF功率,小型蜂窝,POE供电设备,企业交换机/路由器,核心/边缘/城域/光学路由以及电源模块.本文介绍了ADP1074主要特性,框图,多种应用电路以及评估板ADP1074-EVALZ主要特性,电路图,材料清单和PCB设计图.

　　The ADP1074 is a current mode, fixed frequency, active clamp, synchronous forward controller designed for isolated dc to dc power supplies. Analog Devices proprietary iCouplers® are integrated in the ADP1074 to eliminate the bulky signal trans-formers and optocouplers that transmit signals over the isolation boundary. Integrating the iCouplers reduces system design complexity, cost, and component count and improves overall system reliability. With the integrated isolators and metal-oxide semiconductor field effect transistor (MOSFET) drivers on both the primary and the secondary side, the ADP1074 offers a compact system level design and yields a higher efficiency than a non-synchronous forward converter at heavy loads.

　　The primary side pins provide functions for programming the switching frequency, maximum duty cycle, external frequency synchronization, and slope compensation. The secondary side pins provide functions for differential output voltage sensing, overvoltage, power good, tracking, and programmable light load mode setting.

　　The feedback signal and timing of synchronous rectifier pulse-width modulations (PWMs) are transmitted from primary to secondary or from secondary to primary sides through the iCouplers using a proprietary transmission scheme.

　　The ADP1074 also offers features such as input current protection, undervoltage lockout (UVLO), precision enable with adjustable hysteresis, overtemperature protection (OTP), and power saving light load mode (LLM).

　　ADP1074主要特性:

　　Current mode controller for active clamp forward topology

　　Integrated 5 kV rated dielectric isolation voltage with Analog Devices, Inc., patented iCoupler technology

　　Wide voltage supply range

　　Primary VIN: up to 60 V

　　Secondary VDD2: up to 36 V

　　Integrated 1 A primary side MOSFET driver for power switch and active clamp reset switch

　　Integrated 1 A secondary side MOSFET drivers for synchronous rectification

　　Integrated error amplifier and <1% accurate reference voltage

　　Programmable slope compensation

　　Programmable frequency range: 50 kHz to 600 kHz typical

　　Frequency synchronization

　　Programmable maximum duty cycle limit

　　Programmable soft start

　　Smooth soft start from precharged load

　　Programmable dead time

　　Power saving light load mode using MODE pin

　　Protection features such as short circuit, output overvoltage, and overtemperature protection

　　Cycle-by-cycle input overcurrent protection

　　Precision enable UVLO with hysteresis

　　PGOOD pin for system flagging

　　Tracking function from secondary side

　　Remote (secondary side) shutdown/reset function

　　Safety and regulatory approvals (pending)

　　UL recognition

　　5000 V rms for 1 minute per UL 1577

　　CSA component acceptance notice 5A

　　VDE certificate of conformity

　　DIN V VDE V 0884-10 (VDE V 0884-10):2006-12

　　VIORM = 849 V peak

　　CQC certification per GB4943.1-2011

　　Available in 24-lead SOIC_W package

　　ADP1074应用:

　　Isolated dc-to-dc power conversion

　　Intermediate bus voltage generation

　　Telecom, industrial

　　Base station and antenna RF power

　　Small cell

　　PoE powered device

　　Enterprise switches/routers

　　Core/edge/metro/optical routing

　　Power modules

　　图1.ADP1074详细框图

　　图2.ADP1074有源钳位正向拓扑应用电路图

　　图3.ADP1074带起动电路和偏压绕组的有源钳位正向拓扑应用电路图

　　图4.ADP1074有源钳位反激拓扑应用电路图

　　评估板ADP1074-EVALZ

　　The ADP1074-EVALZ evaluation board allows users to evaluate the ADP1074 in a power supply application.

　　The evaluation board can deliver a rated current of 6 A in steady state and 8 A peak that is thermally limited for an input voltage range of 36 V dc to 60 V.

　　Multiple test points allow easy access to all critical nodes and pins.

　　Full data on the ADP1074 is available in the ADP1074 data sheet, which should be consulted in conjunction with this user guide when using the evaluation board.

　　评估板ADP1074-EVALZ主要特性:

　　Fully supported evaluation kit for the ADP1074 active clamp forward topology

　　12.1 V output voltage (VDC)

　　6 A steady state, 8 A peak

　　Programmable light load mode

　　Integrated driver for primary side and secondary side synchronous rectifier

　　External reference signal tracking

　　Precision enabled undervolatge lockout (UVLO) with hysteresis

　　Short circuit, output overvoltage, cycle by cycle input overcurrent, and over temperature protection

　　Frequency synchronization

　　Soft start and soft stop functionality

　　图5.评估板ADP1074-EVALZ外形图

　　评估板ADP1074-EVALZ材料清单:

　　详情请见:

ADP1074.pdf

ADP1074-EVALZ-UG-1115.pdf