OnSemiNCP1380準(zhǔn)諧振電流模式大功率離線電源方案

1、On Semi NCP1380準(zhǔn)諧振電流模式大功率離線電源方案關(guān)鍵詞：電源管理,AC/DC轉(zhuǎn)換器,離線電源On Semi 公司的NCP1380是大功率通用離線電源用的準(zhǔn)諧振電流模式控制器,谷底開(kāi)關(guān)工作,輕負(fù)載時(shí)頻率回饋以提高效率, 峰值電流源/沉為+500mA/-800mA, 無(wú)負(fù)載的待機(jī)功耗極低,適用于TV,STB的大功率AC/DC轉(zhuǎn)換器,筆記本電腦的離線適配器.本文介紹NCP1380主要特性,內(nèi)部電路架構(gòu), 谷底檢測(cè)電路, 過(guò)載檢測(cè)電路, 過(guò)壓/超溫檢測(cè)電路以及典型應(yīng)用電路.Quasi-Resonant Current-Mode Controller for High-Power Univ

2、ersal Off-Line SuppliesThe NCP1380 hosts a highperformance circuitry aimed to powering quasiresonant converters. Capitalizing on a proprietary valleylockout system, the controller shifts gears and reduces the switching frequency as the power loading becomes lighter. This results in a stable operatio

3、n despite switching events always occurring in the drainsource valley. This system works down to the 4th valley and toggles to a variable frequency mode beyond, ensuring an excellent standby power performance.To improve the safety in overload situations, the controller includes an Over Power Protect

4、ion (OPP) circuit which clamps the delivered power at highline. Safetywise, a fixed internal timer relies on the feedback voltage to detect a fault. Once the timer elapses, the controller stops and stays latched for option A and C or enters autorecovery mode for option B and D.Particularly well suit

5、ed for adapter applications, the controller features a pin to implement either a combined overvoltage / overtemperature protection (Version A and B) or a combined brownout/overvoltage protection (Version C and D).NCP1380主要特性: QuasiResonant Peak CurrentMode Control Operation Valley Switching Operatio

6、n with ValleyLockout for NoiseImmune Operation Frequency Foldback at Light Load to Improve the Light Load Efficiency Adjustable Over Power Protection AutoRecovery or Latched Internal Output ShortCircuit Protection Fixed Internal 80 ms Timer for ShortCircuit Protection Combined Overvoltage and Overte

7、mperature Protection (A and B Versions) Combined Overvoltage Protection and BrownOut (C and D Versions) +500mA/800 mA Peak Current Source/Sink Capability Internal Temperature Shutdown Direct Optocoupler Connection Extended VCC Range Operation Up to 28 V Extremely Low NoLoad Standby Power SO8 Package These Devices are PbFree and are RoHS CompliantNCP1380應(yīng)用: High Power acdc Converters for TVs, SetTop Boxes etc. Offline Adapters for Notebooks圖1.NCP1380內(nèi)部電路架構(gòu):A型和B型圖2.NCP1380內(nèi)部電路架構(gòu):C型和D型圖3.谷底檢測(cè)電路圖4.過(guò)載檢測(cè)電路圖