ENGR337 Lab 2018
Lab 2 Use LTSpice for
Due Jan 22, Monday 10 pm.
of this lab:
Be familiar with LTSpice.
Be able to do DC, AC, and trancient analysis.
Create a text file and code the following circuit in Spice
schematic). Use transient analysis to simulate the voltages at all
voltage nodes. Compare the simulation results to your calculation (use
mesh current method to solve it). Build the circuit on your bread board
and measure the node voltages. Put all your calculation, simulation,
and experimental data in a single table in your report.
hint: '.tran 0 1 .01' means 'transient analysis, starting from time 0,
ending at 1 second, step size is 0.01 second. This can be simplified as
'.tran 1', which only shows the ending point at 1s.
Code the following ciruit in Spice (not in schematic). Use transient
analysis to acquire the simulation results. Display the input and the
output signal in one plot, and measure the time-delay, and the
amplitude attenuation of the output signal compare to the input. The
following figure shows you the time-delay. Compare your calculation to
the simulation results.
3. DC sweep.
In DC analysis, the X axis will be a DC voltage other than 'time' in
the following schematic, the circuit ran a DC sweep for the input
voltage from -2 V to 5 V. The X axis will be the 'sweep' of the DV
values for Vin, the Y axis is the voltages that affected by the input.
Implement this circuit
using Spice code, and then show your simulation results in your report.
4. AC analysis (AC sweep)
Ac analysis, the X axis will be 'frequency', the Y axis will be the
amplitude. This is very powerful. Think about that, you can use this
analysis to test the bandwidth of the circuit.
'.ac dec 1000 1 1MEG' means the axis units are in decades of increment,
starting from 1 Hz to 1MEG Hz.
Implement this circuit in
Spice code, and report your results.
** hint: the AC source here can be coded as: 'Vin Vin 0 ac 1'
5. DC pulses
Now let's use DC pulses as the input voltage source to drive a
the Spice code to implement the following circuit and then measure the
time-delay of the circuit. Compare it to your calculation.
the pulse function means PULSE (LowVoltage HighVoltage
Delay RisingTime FallingTime OnTime
Period). The reason that the period is a little longer than the 'On'
time is the rising edge and the falling edge of the pulse are also
taking time even though they are short.
Build this cicuit on a breadboard, and compare the measured time-delay
to your calculations and simulations.
Follow the lab
to avoid losing points.