Microelectronics Assignment

LAB 1: LTSpice Circuit

OBJECTIVE:

In this exercise the students will use LTSpice, Multisim, or a circuit simulation software of their choice to perform circuit simulation. Circuit simulation plays a major role in circuit design. With the software, circuit designers can quickly design, simulatc, and test circuits. To develop skills in circuit simulation and as a review, the students will construct and simulate a circuit to determine the electrical properties and characteristics of the circuit elements.

EQUIPMENT: LTSpice SPICE Simulator, Multisim, or other Circuit Simulation Software
PROCEDURE:

Part I: Resistive Circuit Network

Many times circuit designs consist of complex circuit schematics that may contain hundreds of circuit elements. The knowledge of the voltage and current results for thine elements must be determined. Conventional hand analysis is impractical for these types of circuits, so the electrical properties of the elements must be determined using simulation software.

In the circuit diagram shown below, the student is to capture the circuit using LTSpice and perform a linear DC sweep analysis from I to 10 volts at 0.5 increments. The DC sweep analysis is performed by using the DC dot command.

By clicking on the node for each element, the simulation shows the voltage sweep across that clement. Clicking on the clement itself shows the current going through the clement. Using the results of this simulation analysis, fill in the table below.

(a) Using the DC sweep analysis results from the LTSpice simulation, fill in the table below.

(b) In the simulation, click on the 10 V voltage source, the 12.5Ω, the 10Ω, and the 30Ω resistor to show the current going though each clement. At 10 V, add together the current going through each element. What is the sum of these currents?

Part II: Resistive Circuit Network Comparison

(a) Using the above circuit diagram, change the 10 V voltage source on your schematic to a sine wave function. Give the sine wave a DC offset of 0, an amplitude of 10, and a frequency of 1000 Hz.

(b) Change the DC sweep analysis to a Transient analysis. Set the Stop Time to 20rn seconds with a Step Time of I m.

(c) Run the simulation. Click on the node above the voltage source to get the voltage across the source, and then click directly on the 30Ω resistor to get the current across this clement.

(d) Capture this diagram and put it in your report.

(e) Next, cut the 300 resistor from the schematic and replace it with a 10u Farad capacitor. Repeat the above steps used on the 300 resistor.

(f) Next cut the capacitor from the schematic and replace it with a 1 Orn Henry inductor. Repeat the above steps.

(g) In your report, describe and compare the waveform results in the diagrams for the 30Ω resistor, 10u Farad capacitor, and the 10μ Henry inductor.