2 - FON - How to design with a fixed on-time controllerBi-lingual (Presenting Version)教学讲义.pptVIP

如何采用固定导通时间控制器进行设计 How to Design with a Fixed On-Time Controller 您优化轻载能效的关键所在Your Key to Optimizing Light Load Efficiency;议程Agenda;议程Agenda;准谐振和固定频率 Quasi Resonant and Fixed Frequency;议程Agenda;固定导通时间(FOT)–工作原理 Fixed On Time (FOT) – Principle of Operation;固定导通时间(FOT)–工作原理 Fixed On Time (FOT) – Principle of Operation;议程Agenda;控制拓扑结构比较 Control Topology Comparison;议程Agenda;NCP1351是一款瞄准总成本极为重要的低功率离线反激开关电源(SMPS)应用的电流模式控制器 The NCP1351 is a current-mode controller targeting low power off-line flyback Switched Mode Power Supplies (SMPS) where total cost is of utmost importance;NCP1351 – 输入输出功率和功能描述 NCP1351 – Pinout and Function Description;NCP1351 – 峰值电流压缩 NCP1351 – Peak Current Compression;NCP1351 – 负电流感测…… NCP1351 – Negative Current Sensing…;NCP1351 – 负电流感测…… NCP1351 – Negative Current Sensing…;NCP1351 – 过载/短路保护 NCP1351 – Overload / Short-Circuit Protection;NCP1351 – 过载定时器 Overload Timer; 对MOSFET的BVdss降额后定义变比Define turn ratio after derating the BVdss of the MOSFET:; 推导初级端最大峰值电流 Deduce the maximum primary peak current: 最后通过下列公式估计时序电容值 Finally estimate the timing capacitor value by: MOSFET、整流器、电感和缓冲器根据平均输出功率(非峰值功率)来计算 ;NCP1351 – 设计示例NCP1351 – Design Example;在输入电压为85 Vac及满载时， Cbulk 选择为100 Vdc的最低等级 Cbulk selected for min level of 100 Vdc at Vin = 85 Vac, full load;NCP1351 – 设计示例NCP1351 – Design Example;NCP1351 – 设计示例NCP1351 – Design Example;NCP1351 – 设计示例NCP1351 – Design Example;NCP1351 – 设计示例NCP1351 – Design Example;NCP1351 – 设计示例NCP1351 – Design Example;Vout 1 mV / div.;NCP1351 – 设计示例NCP1351 – Design Example;议程Agenda;将您的固定频率适配器更新为固定导通时间模式！ Update Your Fixed Frequency Adapter to FOT!;仅用于非连续导电模式 DCM onlyDSS - 无辅助绕组