一文详解UCC28780主要特性_功能框图及典型应用电路图

TI公司的ucc28780是高频有源钳位反激控制器，具有自适应控制的全部和部分零电压开关（ZVS）的初级FET，外接Si或GaN FET的可编时序，开关频率高达1MHz，可编程自适应突发控制和待机模式可提高轻负载效率，具有低输出波纹和减轻可听见噪音。主要用在笔记本电脑，平板电脑，TV，机顶盒和打印机的高密度AC/DC适配器，USB供电，直接和快速移动充电器，AC/DC或DC/DC辅助电源。本文介绍了UCC28780主要特性，功能框图和典型应用电路图。

UCC28780 is a high-frequency active-clamp flybackcontroller that enables high-density AC-to-DC powersupplies that comply with stringent global efficiencystandards such as DoE Level VI and EU CoC V5Tier-2. User programmable advanced control lawfeatures allow performance to be optimized for bothSilicon （Si） and Gallium Nitride （GaN） power FETs.

Direct operation with switching devices that combinedriver and GaN FETs is further enhanced with logiclevelgate signals and enable outputs.

Zero voltage switching （ZVS） is achieved over a wideoperating range with advanced auto-tuningtechniques， adaptive dead-time optimization， andvariable switching frequency control law. Usingadaptive multimode control that changes theoperation based on input and output conditions，UCC28780 enables high efficiency while mitigating.

audible noise. With a variable switching frequency ofup to 1 MHz and accurate programmable over-powerprotection， which provides consistent power forthermal design across wide line range， the size ofpassive components can be further reduced andenable high power density.

UCC28780 works with VDS-sensing synchronousrectifier controllers， such as UCC24612， to achievehigher conversion efficiency and very compactdesigns.

UCC28780主要特性：

• Full and Partial Zero Voltage Switching （ZVS） ofPrimary FET with Adaptive Control

• Programmable Timing for External Si or GaNFETs

• High Switching Frequency up to 1 MHz

• Programmable Adaptive Burst Control andStandby Mode for Light-Load Efficiency with LowOutput Ripple and Audible Noise Mitigation

• Brownout Detection without Direct Line Sensing

• Accurate Programmable Over-Power Protection（OPP） to Support Peak Power Mode

• Fault Protections： Over-Temperature， OutputOver-Voltage， Output Short-Circuit， Over-Current，and Pin Fault

• Direct Interface with Optocoupler Based FeedbackAllows for Dynamically Scalable Output Voltage

• Internal Soft Start

• NTC Thermistor Interface with External Enable

UCC28780应用：

• High-Density AC-to-DC Adapters for Notebook，Tablet， TV， Set-Top Box and Printer

• USB Power Delivery， Direct and Fast MobileChargers

• AC-to-DC or DC-to-DC Auxiliary Power Supply

图1.UCC28780功能框图

图2.UCC28780典型应用电路图

图3.UCC28780 45W EVM电路图