power electronics question

[alalim]

why can't we amplify a rectangular (sharp edges) dc signal using conventional amplifiers....

Can you guys explain in detail......i have basic power electronics background

 

[eem2am]

the edges have a high frequency content......so we use the SMPS instead -specially with the power being very big

some people call smps an amplifier......some call it a converter...some a regulator.....some amplifiers in class D mode are like SMPS's

 

[alalim]

I know that the edges have a high frequency compnents......My question is not how can we amplify this signal but it is why can't we amplify using an op-amp......what happens to the op-amp if it tries to amlify this signal.....its a high power signal

 

[VVV]

You can amplify the signal. We do it all the time.
The problem is that with the limted bandwidth of the amplifier the higher order components of the spectrum will be amplified less and there will be phase delays at those frequencies, too. So the end result will be a distorted output.

But this is a fact of life and we live with it. We just quantify the results and see if we can live with them.

Frequently the opamp has a slew-rate limitation that will come into play. That tells you how fast the output can change. If the input edges are faster than the slow-rate capability of the opamp, then your input square-wave will come out looking like a trapezoid or a triangle, because the opamp cannot change its output faster than that.