【问】UCC28060疑问

Current sense input: Connect the current sense resistor and the negative terminal of the diode bridge to this pin. Connect the return of the current sense resistor to the AGND pin with a separate trace. As input current increases, the voltage on CS goes more negative. This cycle-by-cycle over-current protection limits input current by turning off both gate driver (GDx) outputs when CS is more negative than the CS rising threshold (approximately –200 mV). The GD outputs remain low until CS falls to the CS 10 I CfoSllofwalilninggththerefaslhlionlgde(adpgperoofxiemitahteerlyG–D15oumtpVu)t.. CTuhrisrebnltasnekninsgefiisltebrlsannkoeisdefothraatpopcrcouxrims watheelyn1c0u0rrnesnt switches from a power FET to a boost diode. In most cases, no additional current sense filtering is required. If filtering is required, the filter series resistance must be under 100 Ω to maintain accuracy. To prevent excessive negative voltage on the CS pin during inrush conditions, connect the current sensing resistor to the CS pin through a low value external resistor. As with the filter series resistance, this external resistor needs to be under 100 Ω to maintain accuracy.

这个是datasheet的引脚功能摘录，明显看出这个电流检测还是参与了控制

看看规格书中CS端的定义就知道了

CS: 电流检测输入，接到电流检测电阻和整流桥的负端。电流检测电阻的回流端用独立轨迹接到模拟地。随着电流的增大，CS上的电压在增高，变得更负。这个逐个周期式过流保护限制输入电流，它去关断两路栅驱动脉冲。此时CS的电压会超出-200mV阈值，输出保持低电平直到CS端降回-15mv阈值。电流检测信号被消隐100ns，跟随每个GD脉冲的下降沿。这个消隐滤除在电流开关从MOSFET到升压二极管时的噪声。在多数情况下，没有附加电流检测滤波器的要求，如果需要可串一电阻，阻值在100Ω以下，以保持精度。为防止过负的电压在CS端出现，接在电流检测电阻到CS端可用一低值外部电阻，此电阻小于100Ω以保持精度。

说明CS端还是有参与电流环控制的