1. Download the model file for PMOS transistor(from ALD1107 model file) from the “Downloads” .
2. Write ngspice netlist to plot ID/VDS characteristics for the same with the voltage VGS varied from -1.5 V to -3 V in steps of -0.5 V. You may vary VDS from 0 V to -5 V.
Show all the 4 curves on a single plot.
3. From these characteristics, obtain rDS (linear region) for each value of VGS. ”Early voltage” and r0 in saturation region.
Effect of body bias:
1. Bias the transistor in linear region by keeping VDS = 200 mV.
2. Now write ngspice netlist to plot ID/ VGS characteristics by varying VGS from 0 to -5 V for VSB=0V. 3. Repeat the above step to get four more sets of ID/ VGS characteristics for VSB = 1, 2, 3, and 4 V.
4. Show all five ID/ VGS characteristics on the same plot.
5. Obtain the value of threshold voltage from each plot.
6. Plot Vt v/s VSB and find the value of α.
**ALD1107 SPICE Parameter File
.MODEL ALD1107 PMOS (LEVEL=1 CBD=0.5p CBS=0.5p CGDO=0.1p CGSO=0.1p GAMMA=.45 + KP=100u L=10E-6 LAMBDA=0.0304 PHI=.8 VTO=-0.82 W=20E-6)
