NCP1256中文资料低功率离线 PWM 电流模式，带欠电压保护数据手册ONSEMI规格书

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

应用 Application

• Ac−dc Adapters for Portable Devices
• Ac−dc Adapters for Computers
• Ac−dc Adapters for Tablets
• General Ac−dc Adapters
• Ac-dc Adapters

简介

NCP1256属于集成电路（IC）的ACDC转换器离线开关。由制造生产的NCP1256AC DC 转换器，离线开关该系列是元器件级控制产品，用于构建将交流市电转换为直流电（通常电压大幅降低）的设备。集成和未集成系统主要开关元件的器件均包括在内。由于高输入输出电压比，以及此类系统中通常需要隔离，这些器件通常与外部变压器配合使用。尽管通常使用定制变压器来实现此用途，但也有许多专门用于此用途的库存产品，请参见“开关转换器，SMPS 变压器”标题。