[no phase difference]

KEVIN,thanks

The input signal,goes into a power amplifying part,is from a digital signal source.The loads of power amplifying part are inductive or capacitive. A phase shifting would occur between input signal and output signal from power amplifying part. Let output signal to keep track of the input signal phase,nothing done with the input signal.

[no phase difference]

Hello
How to design a analog circuit which has the function following:
the input signal of the circuit is a 50-to-450 Hz sine wave,

1Vrms,the output signal has the same waveform, same frequency,

especially no phase difference(no lead & no lag) with input wave,

other electric characteristics need not care. How to design? Can you

help me?