{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

ECE142_2007FALL_EXAM1__[0]

# ECE142_2007FALL_EXAM1__[0] - the small signal output...

This preview shows pages 1–2. Sign up to view the full content.

ECE142A Fall 2007 1 ECE142A Mid-Term Examination Fall 2007 Wednesday November 7 th - Two Hours Attempt All Questions 1. Sketch the current-voltage characteristics for the transistors shown in Figure 1. Assume that the magnitude of the respective threshold voltages is about 1V. Use the attached sheet for your sketches. [16] Figure 1 2. Derive the small signal input and output impedances for the circuit reproduced in Figure 2. Assume that V A = ± [10] Figure 2 3. Sketch the voltage transfer characteristics (V out vs. V in ) for the circuits shown in figures 3 (a) and (b). Assume that a moderate impedance load is connected from the output to ground. Sweep the input voltage from V ss to V dd or V EE to V CC as appropriate. [20] Figure 3 Q1 Q2 VCC VEE Vout Vin M2 M1 Vdd Vss Vout Vin (a) (b) Rout Rin Q1 Re R2 R1

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
ECE142A Fall 2007 2 4. Write down the configurations for transistors M1 through M3 in the circuit reproduced in Figure 4. Draw the equivalent small signal model for the amplifier (you may ignore
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: the small signal output impedance of the transistors). From your small signal model, write down the nodal equations and thus derive an expression for the small signal voltage gain. [26] Figure 4 5. A BICMOS Darlington configuration is shown in Figure 5. The bias voltage on the gate of M1, V B , is adjusted to set the DC output voltage to 2V with V DD = 5V. Calculate the bias currents in both devices [10] and then calculate the small signal voltage gain for the circuit. Assume a value of 0.77V for V BE . You may ignore the body effect for the MOS transistor or include it for a bonus of 5 marks. The MOS transistor parameters are: μ e C ox = 60 μ A.V-2 , ± = 0.5V 1/2 , 2 | ² F | = 0.7, ³ = 0, W/L = 40/1 and V T0 = 0.8V. For the bipolar transistor: I o = 10-16 A, ´ = 100 and V A = µ . [18] Figure 5 TJC 11/2/07 R1 R2 R3 R4 R5 RL Vin + – rs C1 M1 M3 M2 C2 Vout +-Vdd Vin + – 1k ± M1 Q2 1k ± Vout B V V DD...
View Full Document

{[ snackBarMessage ]}

### Page1 / 2

ECE142_2007FALL_EXAM1__[0] - the small signal output...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online