原标题：TI UCC28633 24V 65W离线反激电源参考设计

　　TI公司的ucc28633是具有初级侧稳压功能和峰值功率模式的高功率反激控制器,内置700V起动电流源,其功能强大的栅极驱动器能工作在CCM和DCM模式,使它适合用在各种功率的电源.峰值电源模式能使瞬态峰值功率高达正常功率的200%,而峰值电流仅增加25%.主要用在笔记本,游戏控制台和打印机的AC/DC适配器,开架SMPS,10W-65W高效AC/DC电源.本文介绍了UCC28633主要特性,框图, 19.5V/65W适配器应用电路图以及24V 65W离线反激电源参考设计主要特性,电路图和材料清单.

　　The UCC2863x targets high-power, primary-side regulated flyback converters. The powerful gate driver and ability to operate in both CCM and DCM make the device suitable for applications with a wide power range. The peak power mode allows transient peak power delivery up to 200% of nominal rating, with only a 25% peak current increase, maximizing transformer utilization.

　　The transformer bias winding is used to sense output voltage for regulation, and for low-loss input voltage sensing. Advanced sampling and processing techniques allow CCM operation, and deliver excellent output voltage regulation performance for opto-coupler-less designs at power levels of 100 W and above.

　　A high-voltage current source enables fast and efficient start-up. Advanced light-load modes are deployed (including switching frequency modulation and device sleep modes) to reduce both controller and system power consumption at no load and light load. These modes enable potential system designs to meet 30-mW no-load power for power designs up to 30 W nominal, 60 W peak.

　　The device has been designed for ease-of-use and incorporates many features to enable a wide range of designs. Extensive protection features are included to simplify system design.

　　UCC28633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 (UCC28630 and UCC28633)

　　Adjustable Constant-Current (CC) Mode Limiting (except for UCC28630)

　　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 Pin Interface for External NTC

　　Protections: Overvoltage, Overcurrent, Over-Temperature, Overload Timer (UCC28630), AC Line UV, Brownout and Pin Protections

　　Frequency Dither to Ease EMI Compliance (except the UCC28632)

　　UCC28633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. UCC28633框图

　　图2. UCC28633 19.5V/65W适配器应用电路图

　　24V 65W离线反激电源参考设计

　　24V 65W Nominal 130W Surge Offline Flyback Power Supply for Industrial Rails Reference Design

　　24V Output, Constant Voltage / Constant Current, 65W Flyback power supply with 130W surge capability. Primary side regulation eliminates feedback opto-coupler and provides 1% regulation down to no-load. Average efficiency of > 89% and no load power of < 70mW are achieved. Voltage input range is 85VAC-265VAC Input.

　　24V 65W离线反激电源参考设计主要特性:

　　Primary Side Regulation (PSR)

　　+/- 1% Voltage Regulation

　　+/- 7.5% Current Regulation

　　<70mW Stand-by Power

　　Short Circuit Protection

　　High Voltage Startup

　　> 85% Efficiency at 10% load

　　图3. 24V 65W离线反激电源评估板外形图

　　24V 65W离线反激电源评估板材料清单: