Other Parts Discussed in Thread: INA286
In this reference design schematic, which can be found at https://www.ti.com.cn/cn/lit/df/tidrp75/tidrp75.pdf?ts=1622029946679ref_url=https%253A%252F%252Fwww.ti.com.cn%252Ftool%252Fcn%252FPMP4486%253FkeyMatch%253D%2526tisearch%253Dsearch-everything%2526usecase%253Drefdesign
l cannot figure out the principles of the ouput current sense of the Buck converter. In this circuit, The resistor R33 and capacitor C51 are in parallel with the Buck inductor. Then the voltage between R32 is connected with the input of operational amplifier INA286. Then the output of the INA286 is the output current sensing signal.
My question is as follow:
1. n this circuit, l think the voltage between the Buck inductor L5 can not reflect the output current information. Why this circuit can realize the funciton of output current sense?
2. The frequency of input signal of INA286 is same as the switching frequency of Buck converter, which is 800kHz. But the bandwidth of INA286 is not enough to transfer the input signal. Where l am wrong?
Looking forward to your instruction. Thank you.
