Self Assessment Quiz

Lecture 13 ,14 and 15 :- Current Sources and References

Common Data : VDD = 1.8V , Lmin  = 0.18µm, µ0N = 350cm2/V s, µ0P  = 100cm2/V s, |VTH | = 0.55, tox = 3.8nm, λ = 0.07V−1, χ = 0.1.

1. Design a simple MOS current mirror of the type shown in Fig. 17 to meet the following constraints.

  1. Transistor must operate in the active region for values of to within from ground .
  2. The output current must be
  3. The output current must change less than 5% for change in output voltage of 0.4V

Figure 17: Figure for Question 1

Make and identical.  You are to minimize the total device area within given constraints. The device area is the total gate area Assume

2. Design a voltage reference using the Beta-multiplier.  Using spice simulation show the temperature performance of your design, by plotting reference voltage vs temperature.

3. Consider the circuit of Fig. 18 assuming and

  1. Determine such that
  2. If deviates from the value calculated by what is the mismatch between and
  3. If the circuit fed by cascode current source changes by by how much does change?

Figure 18: Figure for Question 3

4. Consider the circuit of Fig. 19 with and

  1. Calculate the deviation of from if is less than
  2. Determine the of the amplifier .

Figure 19: Figure for Question 4

5. Calculate the quiscent curent and temperature coefficient of the circuit shown in Fig.20 where and The resistor has a temperature coefficient of

Figure 20 : Figure for Question 5