Pin 14 must not be connected to ground. Chan0_out will be greater than 0 for the positive signal.

LabVIEW Computation

Procedure

• GainSF.vi measures the gain (transfer relation) of the circuit over a range of drain current. Parameters Vtno and knprime are obtained from the ID sweep. Vtno is used in the voltage transfer-relation calculation as plotted along with the measured data.
  
  

  

• Open GainSF.vi and install your value of RS. Open FG1Chan.vi to observe the waveform at the output. Run the VI and verify that the curves match reasonably well as in the example. Adjust the magnitude of VSS to obtain a minimum ID of about 50 μA
  
  
• Adjust the value of Vs while rerunning the VI. Use the largest Vs without distortion. Large-signal distortion is manifested by a poor curve fit, particularly at the low end of the current range.
  
  
• Default and save the Front Panel. The value obtained for knprime must be available for the next VI. It is used in the calculation of . The alternative form, g_m = 2I_D/V_effn, is used in the calculations for this VI.
  
  
• Obtain a data file of the plot using XY1ToDataFile.vi.