ECE 2212

PROBLEM SET 7

S. G. Burns

Due: Friday, 15 March 2013

Note 1: Observe that our regular “Wednesday” Quiz Will Be On FRIDAY, 15 March

Note 2: This change in due date and Quiz 7 date more closely aligns with our class topical coverage and provides additional time for this introductory Chapter 4 material.

Note 3: I will not be assigning Problem Set 8 due the week after Spring Recess.

Note 4: Problem Set 8 and Quiz 8 is scheduled for Wednesday, 3 April

1. Refer to the sketch of an n-channel enhancement-mode MOSFET fabricated in silicon. Assume room temperature operation. Also assume l = 0. Units are important

(a) Compute a value for C_ox .

(b) Compute a value for the threshold voltage, V_t using the threshold voltage graph posted on the WEB page.

(c) Assume W/L = 10 and make reasonable assumptions and/or use values from Table 4.6 for any other physical parameters you may need. Compute values for “k” and “KP” and then use your results from this part and Parts (a) and (b) to generate a Sichmann-Hodges Level 1 model equation.

(d) Using your calculated results from Part (c), sketch and numerically label the i_D versus v_DS as a function of V_GS curves. Label the Saturation, Cutoff, and Ohmic (Triode) regions.

2. Text 4.18 NMOS . In addition, refer to Text Figure P4.18 associated with Text Problem 4.18. Using the SPICE example I will demonstrate in class on Monday, generate a SPICE program by modifying the default NMOS transistor that will match the curves in P4.18 figure. Also note that extracting MOS parameters from the graphical ouput has been used on old quiz problems. Recall, I asked similar model analysis for diodes.

3. Text 4.49 PMOS In addition, refer to Text Figure P4.49 associated with Text Problem 4.18. Using the SPICE example I will demonstrate in class on Monday, generate a SPICE program by modifying the default NMOS transistor that will match the curves in P4.49 figure. Also note that extracting MOS parameters from the graphical ouput has been used on old Quiz problems. Recall, I asked similar model analysis for diodes.

4. From an Old Quiz. For the indicated bias conditions, state whether the FET is operating in the OHMIC (TRIODE) region, SATURATION region, or CUTOFF region. Assume that |V_T | = 2 volts for both the NMOS and PMOS enhancement mode transistors.

M1 __________ M2 __________ M3 __________

M4 __________ M5 __________ M6 __________

All of these cartoons are relevant to life at UMD.