EE236 Assignment2-MOS simulation Solved

Description

Simulation Exercise: PMOS characteristics

1. Download the model file for PMOS transistor(from ALD1107 model file) from the “Downloads” .
2. Write ngspice netlist to plot I_D/V_DS characteristics for the same with the voltage V_GS varied from -1.5 V to -3 V in steps of -0.5 V. You may vary V_DS from 0 V to -5 V.

Show all the 4 curves on a single plot.

3. From these characteristics, obtain r_DS (linear region) for each value of V_GS. ”Early voltage” and r₀ in saturation region.

Effect of body bias:

1. Bias the transistor in linear region by keeping V_DS = 200 mV.
2. Now write ngspice netlist to plot I_D/ V_GS characteristics by varying V_GS from 0 to -5 V for V_SB=0V. 3. Repeat the above step to get four more sets of I_D/ V_GS characteristics for V_SB = 1, 2, 3, and 4 V.
3. Show all five I_D/ V_GS characteristics on the same plot.
4. Obtain the value of threshold voltage from each plot.
5. Plot V_t v/s V_SB 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)

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