| Electronics > Beginners |
| Measuring transconductance of any circuit |
| << < (3/6) > >> |
| Wimberleytech:
Here is another way. Build the test setup using current source and controlled source as shown. Run transient analysis. Measure the voltage at the input of the DUT. Since I and V are known, calculate GM. |
| promach:
--- Quote ---Build the test setup using current source and controlled source as shown --- End quote --- 1) Is E1 a transconductance simulation element ? If yes, it seems not really practical to assign value of 100 to E1 ? 2) Any reason for using "sine" current source ? 3) Why transient analysis ? I suppose doing a DC sweep across Vin and doing derivative on Iout and Vin is the definition of Gm ? |
| Wimberleytech:
--- Quote from: promach on December 16, 2018, 01:16:32 am --- --- Quote ---Build the test setup using current source and controlled source as shown --- End quote --- 1) Is E1 a transconductance simulation element ? If yes, it seems not really practical to assign value of 100 to E1 ? --- End quote --- Why (Why not)? E1 is functioning like an opamp. Something higher than 100 would be better, but I was concerned about convergence. --- Quote ---2) Any reason for using "sine" current source ? --- End quote --- It is easy...it works --- Quote ---3) Why transient analysis ? I suppose doing a DC sweep across Vin and doing derivative on Iout and Vin is the definition of Gm ? --- End quote --- You do not need to do a derivative. Measure delta voltage...you know the delta current. Algebra. |
| promach:
Did you forget the capacitor which is the important component in a gyrator implementation of inductor ? |
| Wimberleytech:
--- Quote from: promach on December 16, 2018, 01:30:14 am ---Did you forget the capacitor which is the important component in a gyrator implementation of inductor ? --- End quote --- No. I am calculating Gm. Certainly Gm has some frequency dependence...you can factor that in when you pick the sine frequency. |
| Navigation |
| Message Index |
| Next page |
| Previous page |