Feedback

Aug 12, 2008 3 Replies

There is a simple (and above all quickly) way to calculate loop gain (given a circuit without any further information)? Thanks


In general, no. Calculation of loop gain involves everything in the loop, as well as the signal source and load properties, though in some special cases, many of those things can be ignored as insignificant.

Regards, John Popelish

The gain of an amplifier using feedback is given by --- A' = A / 1+BA A' = Gain with feedback A = Gain without feedback (open loop gain) B = fraction of output fed back to the input (feedback factor)

bg

Without any further information than you gave? No.

If you're talking circuits, and you know the forward gain, and you know the stage loading at the inputs and outputs, then you can calculate the loop gain. It's a routine 3rd-year analog circuits exercise.

Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" gives you just what it says. See details at http://www.wescottdesign.com/actfes/actfes.html

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required