UNIVERSITY OF CALIFORNIA AT BERKELEY College of Engineering Department of Electrical Engineering and Computer Science R W Brodersen S Emami and D Sobel Homework 1 Due 9 8 04 EECS140 Fall 2004 1 Figure 1 shows the measured ID VDS curves of a 5um 0 15um W L NMOS transistor the data file is attached Figure 1 a Estimate the model parameters Level 1 VT0 k and of this transistor Assume f 0 3 V b Calculate the small signal parameters gm gmb and ro at the operating point A VGS 1 2 V VBS 0 VDS 0 8 V c Use the results of part a to complete the model statement of the following HSPICE netlist to simulate the ID VDS curves of figure 1 the red curves since VBS 0 option nomod post model xtor nmos level 1 vt0 xxx gamma xxx lambda xxx kp xxx capop 0 m1 d g 0 0 xtor w 5u l 0 15u vds d 0 dc 0 8 vgs g 0 dc 1 2 probe dc id i1 m1 dc vds start 0 stop 1 8 step 0 01 vgs 0 9 1 5 0 3 end d Copy the netlist file xxx sp to your working directory and execute HSPICE and Awaves c199 hspice xxx sp xxx lis info hspice job concluded c199 awaves e View the results from Awaves and print out the ID VDS curves Compare the measured and simulated curves and comment on the results Load the design from Design Open and choose the waveform by the Results Browser f Modify the netlist to provide VBS 1 2 V and repeat part d and e for the blue curves of figure 1 2 Figure 2 shows the measured log ID VGS curves of the same NMOS transistor the data file is attached Figure 2 VGS Vth a Assume the sub threshold current can be approximated with I d I 0 e VT 26mV Estimate the value of n for this transistor nVT where b Use the extracted model and procedure of problem 1 to simulate and print out the curves shown in figure 2 log ID VGS and normal ID VGS curves Comment on the accuracy of the simulation results for different regions of operation
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