- (25 points)
The npn transistor used in this problem is a very poor one with
and
. As usual assume
.
Circuit values are given as
,
,
,
,
and
.
The input is given by the sum of a DC
and
an AC
.
Answer the following questions. Show all work.
- Compute the DC operating point. Show all of your work.
(DC)
(DC)
(DC)
(DC)
(DC)
(DC)
- (5 points) Compute the small signal gain of this circuit.
(expression)
(number)
- (5 points) What is the maximum and minimum output voltages (total
signal)
if the small signal input is given by
?
Be sure to consider both the
AC and DC components for all signals.
- (5 points) For what range of output voltages (-15V to 15V) is
the transistor in its active region?
- (25 points)
The npn transistor used in this problem has
and
. As usual assume
.
Circuit values are given as
,
,
,
,
,
and
.
Answer the following questions. Show all work.
- (10 points) Compute the DC operating point.
(DC)
(DC)
(DC)
(DC)
(DC)
(DC)
- (5 points)
Compute the small signal parameters:
- (10 points)
Compute the small signal gain of this circuit.
(expression)
(number)
- (25 points)
The MOSFETs used in this problem have
, infinite Early voltage,
and a threshold voltage of
. Component values are given by:
,
,
and
. Ignore the body effect.
- (10 points)
Write an expression for the small signal gain
.
- (10 points) Choose values for
,
, and the
DC value of
such
that the magnitude of the small signal gain
is ten (to within a few percent) . Explain your reasoning.
Make sure that the values you choose bias the MOSFETs
in the appropriate region. Note that there are many possible correct answers.
- (5 points) Choose values for
and
such that the DC value
of
is as you specified in part (c).
(use this page for extra work if necessary)
- (25 points) Short Answer.
The curves above were measured from either a MOSFET or a bipolar transistor.
- (5 points) Which device were the measurements taken from? Label
the current and voltage axes appropriately. You must explain your answer,
otherwise no credit will be given.
- (5 points) Estimate the Early voltage of this device. Explain.
- (5 points) Compute the DC voltage V assuming
,
and
.
- (5 points) Compute the DC voltage V assuming
,
and
.
- (5 points) Briefly describe the major differences between biasing MOSFETs for
discrete vs. integrated circuit amplifier design.