描述 Description

The NCP1256 includes everything to build cost-effective switch mode power supplies ranging from a few watts up to several tens of watts. Housed in a tiny TSOP-6 package, the part can be supplied up to 30 V. It hosts a jittered 65 or 100-kHz switching circuitry operated in peak current mode control. When the power in the secondary side starts to decrease, the controller automatically folds back its switching frequency down to a minimum level of 26 kHz. As the power further goes down, the part enters skip cycle while limiting the peak current.
NCP1256 comes with several protection features such as a timer-based auto-recovery short circuit protection, lossless OPP, and an easily adjustable Brown Out (BO) pin. Two inputs are provided to latch off the part in a practical way, for instance with OVP and OTP events. Several options exists to chose latch or auto-recovery.

特性 Features

? Frequency Foldback down to 26 kHz and Skip?cycle in Light Load Conditions
? More efficient light load operation
? 70?ms Timer?based Auto?recovery Short?circuit Protection
? Short circuit operation for safety yet reliable with auto-recovery for flexible restart
? Frequency Jittering in Normal and Frequency Foldback Modes
? Jitter reduces EMI by spreading the switching sprectrum over a wider band
? +500 mA/ ?500 mA Source/Sink Drive Capability
? Ability to drive larger FETs
? Pb?Free Device
? Environment friendly
? Fixed?frequency 65?kHz or 100?kHz Current?mode Control Operation
? Adjustable Over Power Protection (OPP) Circuit, Disabled at Low Line
? Adjustable Brown Out Level
? Internally?fixed Slope Compensation Ramp
? Internally?fixed 4?ms Soft?start
? Double Hiccup Auto?recovery Short?circuit Protection
? Pre?short Ready for Latched OCP Option
? Latched OVP Protection on Vcc
? Latched Inputs for Improved Robustness (OVP and OTP implementations)
? EPS 2.0 Compliant

應用 Application

? Ac?dc Adapters for Portable Devices
? Ac?dc Adapters for Computers
? Ac?dc Adapters for Tablets
? General Ac?dc Adapters
? Ac-dc Adapters

簡介

NCP1256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NCP1256AC DC 轉(zhuǎn)換器，離線開關(guān)該系列是元器件級控制產(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”標題。