UCC28019是怎样采样整流后的正弦半波波形供电流环路跟随的？

从IC内部功能图上看，Vin 管脚没有这项功能。

实现电流跟随的是红色方框所圈入的。可以这样理解：在PWM的D不变的情况下（可以认为此时芯片还没来得及改变它的占空比D），输入Vin的变化将引起跨导误差放大器gmv的输出“误差电流”的变化，因为Vin是呈现正弦半波形状的，故这个“误差电流”也将是半波正弦变化的，这样就可以把这个信息调制到gmi的电流控制上，实现电流的正弦跟随。

不知有没回答你的问题？

Hi

    见datasheet的描述：The output stays low for a minimum off-time, tOFF(min), after which the ramp rises linearly to intersect the ICOMP voltage. The
ramp-ICOMP intersection determines tOFF, and hence DOFF. Since DOFF = VIN/VOUT by the boost-topology equation, and since VIN is sinusoidal in wave-shape, and since ICOMP is proportional to the inductor current, it follows that the control loop forces the inductor current to follow the input voltage wave-shape to maintain boost regulation.Therefore, the average input current is also sinusoidal in wave-shape.

   功率校正是通过输入电压和电流的相位调整，所以是要电流采样ISense,和电压采样Vins, 我个人是认为上述的框架图不是很准确的。