1
Ve311 Homework #5
Note:
(1) Please use A4 size papers.
(2) Please use the SPICE model on page 2 for simulation and calculation.
1. [Common-Source with Resistive Load]
(a) [40%] Assume λ = 0 and γ = 0. For VDD = 5 V, Vin = 0.9 V + small
signal, RD = 15 kΩ and Ldrawn = 2 µm, find out the value Wdrawn to obtain
a voltage gain |Aυ
| > 10 and VOUT (the DC biasing voltage at the output)
close to 2.5 V as much as possible.
(b) [30%] Using the DC biasing condition in (a), plot VOUT as a function
of VIN (from 0 V to 5 V) by DC sweep in Pspice. Compare the handcalculation result in (a) with the simulation result here. Note: the slope of
the VOUT versus VIN curve at VIN = 0.9 V is the Av
.
(c) [30%] Using the DC biasing conditions in (a), plot Vout as a function
of time (from 0 to 0.1 second) in Pspice, when Vin = 0.9 V + B ×
sin(2π100t) and B = 0.01 V, 0.1 V and 1 V. What do you observe when
the amplitude increases?
2
Vacuum permittivity (𝛜𝐨) = 𝟖. 𝟖𝟓 × 𝟏𝟎−𝟏𝟐 (F / m)
Silicon oxide dielectric constant (𝛜𝐫
) = 𝟑. 𝟗
