Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Capacitor a nonlinear device???

Status
Not open for further replies.
The formula expects constant C. Non-linear capacitor means C = f(V), so the equation becomes invalid in any case.
 

In fact, there is no "linear" device at all!
Neither a resistor nor a capacitor.
However, for some applications we are allowed to treat such devices as "linear" - as long as the error introduced through such a simplification can be tolerated!
 

Capacitor charging or discharging do not follow y=mx straight line . Rather in both the cases exponential growth/decay of charge happens. SO Q=CV is not same as y=mx.
 

Capacitor charging or discharging do not follow y=mx straight line . Rather in both the cases exponential growth/decay of charge happens. SO Q=CV is not same as y=mx.

Look at that equation again. Twice the voltage means that twice the difference in charge carriers between the plates. By the way, a cap at 1000 volts contains the same number of net charge carriers as a cap at zero volts. So when you "charge" a capacitor or battery, what are you charging it with?

Ratch
 

Every capacitor has a voltage coefficient of capacitance
and for many it is significant. MOS capacitors and junction
capacitors are extremely nonlinear in some regions of
operation and require extra care. Same for polarized
electrolytics and tantalum (also electrolytic) types.
And of course breakdown (preceded by increased
leakage,which is a charge loss) is mighty nonlinear
and probably not the same, the second time either.

At some point you may have to step away from simple
arithmetic and do an integral int(C(V)dV). This point,
seems to be the original question but there is not a
single simple answer until you get to a specific part
and its technology attributes.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top