1 ADS Tutorial # 6 Customize MOSFET Model and Simulation 1. Circuit Construction a. From Component Pallet In component pallet, find “Device-MOS” and choose “Bsim3”, as shown in Figure 1. According to the application, different MOSFET model may be taken. Figure 1 b. Detailed parameters in “Bsim3” model are shown in Figure 2. If there is no value of any parameter, it means the default value is taken. The default value for each parameter can be found in http://www-device.eecs.berkeley.edu/~bsim3/ website. 2 Figure 2 c. Above Bsim3 model, there is a MOSFET model, “NMOS”. Place it on schematic. Make sure the model name use in NMOS symbol is matched that in Bsim 1 model, as shown in Figure 3. Figure 3 3 2. Do DC simulation on a single MOSFET transistor (Figure 4) a. Sweep Vds and measure Id, I-Probe 1. b. Parameter sweep Vgs. Figure 4 c. Id-Vds with parameter sweeping Vgs (Figure 5). m1 Vds= I_Probe1.i=0.002 Vgs=3.000000 3.500 m2 Vds= I_Probe1.i=0.001 Vgs=2.500000 4.100 123405 0.5 1.0 1.5 2.0 2.5 0.0 3.0 Vds I_Probe1.i, mA m1 m2 Figure 5 4 3. Simulate common-source amplifier with drain resistance load a. Use DC simulation to find out the bias point, as shown in Figure 6. (a) 123405 1 2 3 4 0 5 Vgs Vo, V (b) Figure 6 b. From Figure 6 (b), we could tell Vgs=2.2 V giving better bias point. c. AC simulation is used to find out the voltage gain, 13.7 dB, as shown in Figure 7. 5 (a) m1 freq= dB(Vo/Vi)=10.778 14.14GHz 1E4 1E5 1E6 1E7 1E8 1E9 1E101E3 1E11 5 6 7 8 9 10 11 12 13 4 14 freq, Hz dB(Vo/Vi) m1 (b) Figure 7 . 1 ADS Tutorial # 6 Customize MOSFET Model and Simulation 1. Circuit Construction a. From Component Pallet In component pallet, find “Device-MOS” and choose “Bsim3”,. Figure 2 c. Above Bsim3 model, there is a MOSFET model, “NMOS”. Place it on schematic. Make sure the model name use in NMOS symbol is matched that in Bsim 1 model, as shown in Figure 3 resistance load a. Use DC simulation to find out the bias point, as shown in Figure 6. (a) 123405 1 2 3 4 0 5 Vgs Vo, V (b) Figure 6 b. From Figure 6 (b), we could tell Vgs=2.2