For brushless motor driver, the typical circuit is shown as below. Each phase is driven by PWM pulses.
In order to sense the current of each phase, current sensing OP-AMPs are needed.
MAX40056 series are designed for such applications. It has very good PWM rejection.
● Fast, 2μs PWM Edge recovery (1%) from 500V/μs PWM Edges ● 60dB AC CMRR Rejection at 50V, ±500V/μs PWM Edges