# Can someone explain small signal duty cycle

#### mike _Jacobs

Joined Jun 9, 2021
223
So of course we have the standard small signal analysis for solving non linear circuits.

In general i always think of the AC component that rides on top of the DC bias.

I cam across a book that is trying to define small signal duty cycle in the context of switching converters.
I dont understand what small signal duty cycle is.

duty cycle in this context is a square wave so what is small signal duty cycle?

The only thing i can think of is the AC component from the average signal.
But isnt that just the duty cycle?

#### BobTPH

Joined Jun 5, 2013
9,255
Duty cycle is a pure number between 0 and 1.

Presumably, the book you read gave a definition of “small signal duty cycle.” I have never heard the term before.

#### crutschow

Joined Mar 14, 2008
34,818
In usual electronic analysis, large-signal includes the non-linear elements in the analysis, and small-signal assumes all the elements are linear, so not sure what small-signal duty-cycle is.

Apparently the author of that book has an unconventional definition for that term.
Doesn't he define that term somewhere in the book?

#### mike _Jacobs

Joined Jun 9, 2021
223
In usual electronic analysis, large-signal includes the non-linear elements in the analysis, and small-signal assumes all the elements are linear, so not sure what small-signal duty-cycle is.

Apparently the author of that book has an unconventional definition for that term.
Doesn't he define that term somewhere in the book?
That is always what i understood also.
@ 1.30 in the video he says small cycle duty cycle

#### kubeek

Joined Sep 20, 2005
5,796
I would read 'small signal duty cycle' as a constant that comes out of the steady state that you use for the small signal analysis.

#### MisterBill2

Joined Jan 23, 2018
19,366
A "small Signal Duty Cycle" would be a square wave type PWM signal operating within the linear operating conditions of the devices. Just because a device can function with a square wave does not mean that it has to be running in a switching mode of saturation and cutoff.
Of course it must also be operating within it's frequency response range.