NCP1247中文资料PWM 控制器，固定频率，反激转换器，USB-Pd 参考设计数据手册ONSEMI规格书

描述 Description

The NCP1247 is a new fixed-frequency current-mode PWM controller featuring Dynamic Self-Supply. This function greatly simplifies the design of the auxiliary supply and the Vcc capacitor by activating the internal startup current source to supply the controller during start-up, transients, latch, stand-by etc. This device contains a special HV detector which detects the application unplug from the AC input line and triggers the X2 discharge current. The HV structure also includes brown-out detection circuitry. The NCP1247 features a timer-based fault detection that ensures the detection of overload and an adjustable power compensation to help keep the maximum power independent of the input voltage. Due to frequency foldback, the controller exhibits excellent efficiency in light load condition while still achieving very low standby power consumption. Internal frequency jittering, ramp compensation, and a versatile latch input make this controller an excellent candidate for robust power supply designs. A dedicated off mode allows the SMPS to reach extremely low no load input power consumption when combined with secondary side controller NCP4353 or NCP4354. When used together, the SMPS is capable of achieving NCP1247 - Adds C & D option for different Brown Out threshold- Enhanced operation with Sync Rec in light load- Increased HV timer- Revised X2 discharge sequence
This product is IEC60950 compliant. Please see the test report and certification in the Conformance report section below.

特性 Features

• Frequency foldback and skip mode
• Timer-based overload protection with latched (A version) or auto-recovery (B version) operation
• High-voltage startup with dynamic self supply
• Integrated brown-out detection
• Frequency Modulation
• Adjustable overpower protection
• Latch off input
• Protection against faults

应用 Application

• AC-DC Adapters
• LCD TV power supplies
• USB-Pd (USB Power Delivery)
• Offline USB Pd
• Offline USB Power Delivery SMPS

简介

NCP1247属于集成电路（IC）的ACDC转换器离线开关。由ONSEMI制造生产的NCP1247AC 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。