原标题：TI UCC28630高度集成大功率反激电源解决方案

　　TI 公司的UCC28630是高度集成大功率反激电源控制器,连续导通模式(CCM)和不连续导通模式(DCM)工作,内置700V起动电流源,有源X电容放电功能,恒流(CC)模式限制,高栅极驱动电流,30mW系统待机功耗,主要用在笔记本电脑,游戏控制台个打印机的AC/DC适配器,工业,白家电,LCD监视器的开架开关电源,以及10W-65W的高效AC/DC电源.本文介绍了UCC28630主要特性, 功能框图以及评估板UCC28630EVM-572(9.5-V, 65-W笔记本电脑适配器)主要特性,电路图,材料清单和PCB元件布局图.

　　The UCC28630 device is a highly-integrated, primary-side-regulated (PSR) flyback controller. The device supports magnetically-sensed output voltage regulation via the transformer bias winding. This feature eliminates the need for a secondary-side reference, error amplifier and opto-isolator. The device employs an advanced internal control algorithm that offers accurate static output voltage regulation against line and load. The fixedpoint, magnetic-sampling scheme allows operation in both continuous conduction mode (CCM) and discontinuous conduction mode (DCM). Additionally, the device achieves accurate constant-current (CC) control of the output current limit using only primary-side, current sensing. Uniquely, this CC function operates seamlessly as the operating mode changes between DCM and CCM operation.

　　The controller includes an internal, high-voltage (HV) start-up current-source, and employs low-power sleep modes and switching frequency reduction, to improve light-load efficiency and standby power. The device typically achieves standby power levels between 0.05% and 0.1% of peak output power. The controller operates in either DCM and CCM, using a mix of peak current-mode PWM (AM) and switching frequency modulation (FM) schemes. The control approach improves performance (efficiency, size and cost) and can reduce transformer size and cost by allowing operation in CCM with FM during peak overload conditions.

　　Extensive protection features are incorporated, including output overvoltage protection (OVP), bias rail overvoltage and undervoltage (OV/UV), active X-capacitor discharge, line undervoltage and brownout protection, overcurrent overload timer, open- and short-circuit terminal protections, peak current adjustment with line and frequency dither for system EMI reduction.

　　UCC28630主要特性:

　　High-Power, Primary-Side Regulation for Output Voltage and Current, No Opto-Coupler Required

　　Continuous Conduction Mode (CCM) and Discontinuous Conduction Mode (DCM) Operation

　　Built-In 700-V Start-Up Current Source

　　Active X-Capacitor Discharge Function

　　Constant-Current (CC) Mode Limiting

　　High Gate Drive Current 1-A Source and 2-A Sink

　　Low Power Modes for <30-mW System Standby

　　Best-In-Class Light Load (10%) Efficiency >85% for 65-W Nominal Power Design

　　Peak-Power Mode for Transient Overload

　　Shutdown Terminal Interface for External NTC

　　Protections: Overvoltage, Overcurrent, Over-Temperature, Overload Timer, AC Line UV, Brownout and Terminal Protections

　　Frequency Dither to Ease EMI Compliance

　　UCC28630应用:

　　• AC-DC Adapters for Notebook, Game Consoles Printers

　　• Open Frame SMPS for Industrial, Printer, White Goods, LCD Monitors.

　　• Energy Efficient AC-DC Supplies for Nominal Power 10-W to 65-W, (with up to 200% transient peak power)

　　图1.UCC28630功能框图

　　图2.UCC28630简化应用电路图

　　评估板UCC28630EVM-572

　　The UCC28630EVM-572 evaluation module is a 65-W nominal, 130-W peak off-line flyback converter. It provides constant-voltage (CV) and constant-current (CC) output regulation using the bias winding to sense a scaled proportion of the output voltage and the primary current sense resistor to sense a scaled version of the secondary current. Output voltage regulation within 1% is maintained down to no-load by reducing the switching frequency and the device bias current consumption This evaluation module uses the UCC28630 High-Power Flyback Controller with Primary-Side Regulation and Peak-Power Mode in a 65-W converter to provide a regulated output voltage of 19.5 V. The input accepts a voltage range of 90 VAC to 265 VAC. The output is designed for 19.5 V when in constant voltage mode and 3.34-A nominal output current.

　　The EVM transiently delivers ~7 A of constant charge down to an output voltage of ~12 V. The unit can only transiently operate at > 140% of the nominal output power. The operation of the overload timer is explained in detail in the UCC28630 datasheet. Sustained operation above this power level causes the device to inhibit switching and enter hiccup fault mode until the overload is removed. The modulation of peak current and frequency results in excellent no-load power (<70 mW), no audible noise and small core size to deliver the 130-W peak power.

　　The UCC28630 also employs frequency dithering to reduce conducted emissions and therefore reduce the size and cost of the EMI filter.

　　This user’s guide provides the schematic, component list, assembly drawing, art work, and test set up necessary to evaluate the UCC28630EVM-572.

　　图3.评估板UCC28630EVM-572外形图

　　评估板UCC28630EVM-572主要特性:

　　• AC Input Range 90 VAC to 265 VAC

　　• DC Output of 19.5 V, 3.34 A

　　• No-Load Power Consumption Less than 70 mW

　　• Primary-Side feedback for Constant Voltage and current Regulation

　　• ±1% Output Voltage Regulation

　　• ±10% Output Current Regulation

　　• Average Efficiency > 88%

　　• Output Over-Load Timer

　　• Short Circuit Protection

　　• Transient Power Delivery of >130 W

　　• Output Over Voltage Protection

　　• Input Brown-Out Protection

　　• Fault Protections Including Over Temperature, Output Over-Voltage and Output Overload, Input Brownout

　　• Class B EMI Compliance

　　评估板UCC28630EVM-572材料清单: