原标题：PowerIntLNK36042.5W非隔离反激转换器参考设计DER-578

　　Power Integrations公司的LinkSwitch-XT2系列是高效离线开关电源IC,集成了725V功率MOSFET,振荡器,简便ON/OFF控制方案,高压开关电流源,频率抖动,逐个周期限流和热关断电路.具有容易设计和优于线性/RCC的特性,主要用在电器,工业系统和仪表的电源.本文介绍了LNK3604产品亮点和功能框图,典型应用电路以及2.5W通用输入非隔离反激转换器参考设计DER-578主要特性,电路图,材料清单和PCB设计图.

　　LinkSwitch™-XT2 incorporates a 725 V power MOSFET, oscillator, simple ON/OFF control scheme, a high-voltage switched current source, frequency jittering, cycle-by-cycle current limit and thermal shutdown circuitry onto a monolithic IC. The start-up and operating power are derived directly from the DRAIN pin, eliminating the need for a bias winding and associated circuitry.

　　LNK3604产品亮点:

　　Easy to Design

　　Lowest component count switcher solution

　　Selectable device current limit

　　Fully integrated auto-restart for short-circuit and open-loop protection

　　Optional self-biased supply

　　Frequency jittering greatly reduces EMI

　　Meets HV creepage requirements between DRAIN and all other pins both on the PCB and at the package

　　Pin-out simplifies PCB heat sinking

　　Features Superior to Linear/RCC

　　Output overvoltage protection (OVP)

　　Input overvoltage line protection (OVL)

　　Hysteretic over-temperature protection (OTP)

　　Extended creepage between DRAIN pin and all other pins improves field reliability

　　725 V MOSFET rating for excellent surge withstand

　　Extremely low component count enhances reliability Allows single-sided PCB and full SMD manufacturability

　　EcoSmart™ – Extremely Energy-Efficient

　　Easily meets all global energy efficiency regulations

　　No-load consumption <100 mW without bias winding at 265 VAC input (<10 mW with bias winding)

　　ON/OFF control provides constant efficiency to very light loads

　　LNK3604应用:

　　Supplies for appliances, industrial systems, and metering

　　图1.LNK3604功能框图

　　图2.LNK3604通用输入设计电路

　　2.5W通用输入非隔离反激转换器参考设计DER-578

　　2.5W参考设计DER-578主要特性:

　　· Lowest component count for a non-isolated flyback solution

　　· Output voltage regulation, ±5%

　　· Programmable current limit for clampless design

　　· Reduced dissipation during output short circuit fault

　　· <10 mW no-load input power at 230 VAC

　　· >75% Efficiency at full load condition

　　· >6 dB conducted EMI margin

　　This engineering report describes a non-isolated flyback converter designed to provide a

　　nominal output voltage of 5 V at 500 mA load from a wide input voltage range of 85 VAC

　　to 265 VAC. This adapter utilizes the LNK3604D from the LinkSwitchTM-XT2 family of

　　devices.

　　图3.2.5W参考设计DER-578外形图(顶视图)

　　图4.2.5W参考设计DER-578外形图(底视图)

　　2.5W参考设计DER-578主要指标:

　　图5.2.5W参考设计DER-578电路图

　　2.5W参考设计DER-578材料清单:

　　详情请见:

linkswitch-xt2_family_datasheet.pdf

der578.pdf