描述 Description

Housed in a SO-14 package, the NCP1381 includes everything needed to build rugged and efficient Quasi-Resonant (QR) Switching Power Supplies. When powered by a front-end Power Factor Correction circuitry, the NCP1381 automatically disconnects the PFC controller in low output loading conditions (with an adjustable level), thus improving the standby power. This is particularly well suited for medium to high power offline applications, e.g. notebook adapters.When the current setpoint falls below a given value, e.g. the output power demand diminishes, the IC automatically enters the so-called skip cycle mode and provides excellent efficiency at light loads. Because this occurs at an adjustable low peak current together with a proprietary Soft-Skip technique, no acoustic noise takes place. Skip cycle also offers the ability to easily select the maximum switching frequency at which foldback and standby take place.The NCP1381 also features several efficient protection options like a) a short-circuit overload detection independent of the auxiliary voltage b) an auto-recovery brown-out detection and c) an input to externally latch the circuit in case of Overvoltage Protection or Over Temperature Protection.NCP1381 vs. NCP1382 Latchoff Level On the Skip Adjustment Pin:3.5 V Typ - NCP13812.5 V Typ - NCP1382

特性 Features

? Current-Mode Quasi-Resonant Operation
? Adjustable Line Over Power Protection
? Extremly Low Startup Current of 15 uA Maximum
? Soft-Skip? Cycle Capability at Adjustable Peak Currents
? Plateau Sensing Overvoltage
? Brown-out Protection
? Maximum TON Limitation
? Overpower Protection by Current Sense Offset
? Internal 5ms Soft-Start Management
? Short-Circuit Protection Independent of Auxiliary Level
? External Latch Input Pin for an OTP Signal
? Go-To-Standby Signal for the PFC Front Stage
? True Frequency (TON + TOFF) Clamp Circuit
? Low and Noiseless, No-Load Standby Power
? Internal Leading Edge Blanking
? +500 mA/-800 mA Peak Current Drive Capability
? 5 V/10 mA Reference Voltage

簡介

NCP1381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NCP1381AC 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。