描述 Description

The NCP1365 offer a new solution targeting output power levels from a few watts up to 20 W in a universal-mains flyback application.
Thanks to a novel method this new controller eliminates the need for a secondary feedback circuitry (typically an opto-coupler and TL431 reference) while achieving excellent line and load regulation.
The NCP1365 operates in valley lockout quasi-resonant peak current mode control mode at high load to provide high efficiency. When the power on the secondary side starts to diminish, the controller automatically adjusts the duty-cycle then at lower load the controller enters in pulse frequency modulation at fixed peak current with a valley switching detection. This technique allows keeping the output regulation with tiny dummy load. Valley lockout at the first 4 valleys prevent valley jumping operation and then a valley switching at lower load provides high efficiency.

特性 Features

? No frequency clamp, 80 or 110 kHz Maximum Switching Frequency
? Prevents high frequency interference with a touchscreen
? Quasi-Resonant with Valley Switching Operation
? Offers high efficiency operation
? 560-V Startup Current Source
? Saves external HV FET or inefficient resistor divider
? Fixed Peak Current & Deep frequency foldback @ light load operation
? Low consumption at light load
? Cycle by Cycle peak current limit
? Safe operation
? Wide Operation VCC range (up to 28 V)
? Design flexibility
? Internal Temperature Shutdown
? Safe operation
? CS & Vs/ZCD pin Short and Open Protection
? Safe operation
? Constant Current Primary-side feedback eliminates secondary controller
? ±10% Current Regulation
? Build-in soft-sart
? Low Start-up current (2.5 μA typ.)
? Clamped Gate-drive Output for Mosfet
? Less than 10 mW No-Load Performance

應(yīng)用 Application

? AC-DC USB chargers for cell phones, tablets, and other portable devices
? AC-DC USB chargers for cell phones, tablets, and other portable devices

簡介

NCP1365屬于集成電路（IC）的ACDC轉(zhuǎn)換器離線開關(guān)。由制造生產(chǎn)的NCP1365AC DC 轉(zhuǎn)換器，離線開關(guān)該系列是元器件級(jí)控制產(chǎn)品，用于構(gòu)建將交流市電轉(zhuǎn)換為直流電（通常電壓大幅降低）的設(shè)備。集成和未集成系統(tǒng)主要開關(guān)元件的器件均包括在內(nèi)。由于高輸入輸出電壓比，以及此類系統(tǒng)中通常需要隔離，這些器件通常與外部變壓器配合使用。盡管通常使用定制變壓器來實(shí)現(xiàn)此用途，但也有許多專門用于此用途的庫存產(chǎn)品，請參見“開關(guān)轉(zhuǎn)換器，SMPS 變壓器”標(biāo)題。