原标题：Diodes AP3917B通用AC高压输入电源解决方案

　　Diodes公司的AP3917B/C/D是通用AC高压输入(90-265VAC)降压功率开关器,和单绕组电感工作,集成了650V(AP3917B/C)或700V(AP3917D) MOSFET,使得它可以用较少的外接元件,从而获得低材料清单(BOM)成本的解决方案.AP3917B/C/D可以得到极好的调节性能和高的功率效率.当负载降低时峰值电流和开关频率连续降低,这样在轻负载时就能得到极好的效率性能,从而提高了整个系统的效率.AP3917B/C/D还有多种保护特性,以增强系统安全性和可靠性.它具有超温保护,欠压锁住功能,输出短路保护,过载保护和开路保护.AP917B/C/D的额定输出电流为170/270/370mA(最大值),无负载功耗小于30mW(带外接偏压).主要用在隔离和非隔离家用电器.本文介绍了AP3917B主要特性,框图,典型应用电路图以及评估板AP3917B EV3主要特性和系统性能,电路图,材料清单,变压器电路图和PCB设计图.

　　The AP3917B/C/D is a universal AC high-voltage input, step-down power switcher. The main applications are especially suited for home appliance and IoT applications with a non-isolated buck solution or offline flyback solution.

　　Working with a single-winding inductor and integrating a 650V(AP3917B/C) or 700V(AP3917D) MOSFET internal can make the device use fewer external components and create a low bill of material (BOM) cost solution.

　　The AP3917B/C/D can achieve excellent regulation and high power efficiency. The peak current and switching frequency continuously reduce as the load decreases, so it can get excellent efficiency performance at light load and improve the overall system efficiency.

　　The AP3917B/C/D has multiple protection features to enhance the system safety and reliability. It has over temperature protection, under-voltage lock function, output short protection, overload protection, and open-loop protection.

　　AP3917B应用:

　　Non-Isolated and Isolated Home Appliances

　　AP3917B主要特性:

　　Universal 90 to 265 VAC Input Range

　　Internal MOSFET of 650V/650V/700V for AP3917B/C/D

　　Improved Constant Voltage: ±5%

　　Maximum 170/270/370mA Rated Output Current for AP917B/C/D

　　No Load Power Consumption: < 30mW With External Bias

　　Frequency Modulation to Suppress EMI

　　Various Protections: OTP, OLP, SCP

　　Fewer Components

　　Low Audible Noise Solution

　　图1.AP3917B框图

　　图2.AP3917B典型应用电路图

　　评估板AP3917B EV3

　　Dual Output Off-Line Buck + Fly-back Power Solution AP3917B 12V/20mA+3.8V20mA EV3 Board User’s Guide

　　AP3917B is an off-line universal AC Voltage input step-down regulator that provides accurate constant voltage (CV), outstanding low standby power, light loading efficiency and dynamics performance. The chip supports non-isolated buck and buck-boost topology, and also isolated and non-isolated flyback topology. The main applications are for cost-effective home appliance power.

　　Working with a single winding inductor and integrating a 650V MOSFET when used in buck topology, the BOM cost is very low.

　　The AP3917B EV3 Evaluation Board contains two outputs specifications: 12V20mA and 3.8V20mA, with both non-isolations flyback. The two outputs share a three-winding transformer. The feedback circuitry samples 3.8V output. The user’s guide provides good design example for dual output power applications in home appliance power.

　　评估板AP3917B EV3主要特性:

　　 Universal 85V to 264V VAC Input

　　 Internal MOSFET 650V (Rds(on) 10Ω max. @25℃)

　　 Maximum output Current: 170mA typ.@5V output

　　 Low Standby Power Consumption

　　 High Light Loading Efficiency and average efficiency can meet DOE IV and CoC V5 Tier 2

　　 Frequency Modulation to suppress EMI to meet EN55032 and FCC part 15 class B

　　 Rich Protection including: OTP, OLP, OLD,SCP

　　 Extremely low system component count.

　　 Totally Lead-free & Fully RoHS Compliant (SO-7)

　　 Halogen and Antimony Free.“Green” Device

　　评估板AP3917B EV3应用:

　　 Non-Isolated Home Appliances including: AC Fans, Rice Cooker, Air conditioner, Coffee Machines, Soy Milk Machines, ect.

　　 Auxiliary Power to IoT Devices.

　　图3.评估板AP3917B EV3外形图:左:顶视图;右:底视图

　　评估板AP3917B EV3系统性能:

　　图4.评估板AP3917B EV3电路图

　　评估板AP3917B EV3材料清单:

　　图5.评估板AP3917B EV3 PCB布局图:左:顶层;右:底层.

　　图6.评估板AP3917B EV3变压器电路图