Homework 4-7
1250
F 14
1.
Find the output voltage for the following circuits that represent the signal from an
electrode (vs and R) driving an R Parallel, with and without a voltage follower.
Assume vs = 1 mV.
a)
b)
2.
Using the Circuit System Design (CSD) Cards, show that the output voltage of a
voltage follower is unchanged when an R Parallel is connected to its output.
ANS:
1. a) vo ≈ 1 µV b) vo = 1 mV
2. For Voltage Follower: vTh = vTh< and RTh ≈ 0 Ω .
For Voltage Follower followed by R Parallel:
R
R
vTh = GvTh< =
vTh< = vTh< = vTh< and
R + RTh<
R
RTh = R || RTh< = R || 0 Ω = 0 Ω
The answers are the same for both circuits.