SPICE-Simulation using LTspice IV

10. Project 6: OP Amp Circuits
10.1. Let us start with an Inverting Amplifier
Let us have a look at a simple OP Amp circuit using one of the LT models which come with the software.
Task:
To simulate an inverting amplifier with the „LT1001“ to have the following specifications:
Gain
= 10 (= 20dB)
Input Resistance
= 1 k
Use two power supplies with +15V and -15V
The input signal is a sine wave with a peak value of 1V and a frequency of 1kHz. Simulate the input and
output voltage from 0...10ms.
Solution:
You see, as predicted by theory, that there is a phase shift of 180 degrees between input and output.
Additional task:
Use an AC sweep to determine the frequency response and the upper cutoff frequency. Simulate up to
1MHz.
Solution:
In the properties of the voltage source V3 set AC amplitude = 1 and AC phase = 0
.
Then write the simulation command
.ac dec 101 1 1MEG
for a decadic sweep with 101 points per decade from 1 Hz to 1MHz.
62