ENEE417 (PermReq) Microelectronics Design Laboratory; (2 credits) Grade Method: REG.
Prerequisite: ENEE 306 and ENEE 312 and completion of all lower-division technical courses in the curriculum. For ENEE majors only. Senior capstone project laboratory, where student design and build fairly sophisticated circuits, mainly composed of discrete transistors and integrated circuits. Many of the projects are designed to require that students synthesize from what they have learned in many of the disciplines in electrical engineering. Students learn they can actually use their knowledge to build something very practical, which may include a high-fidelity amplifier, a radio, a memory cell, a transmitter, etc.

 

0101(24051) Yang, C. (FULL: Seats=8, Open=0, Waitlist=0) Chia-Hung Yang, email: yang@eng.umd.edu

M......... 8:00am-11:00am (AVW 1330) Lab

0104(24053) Yang, C. (Seats=8, Open=1, Waitlist=0) Nicole Nelson, email: nmnelson@umd.edu

W......... 4:00pm- 7:00pm (AVW 1330) Lab

0105(24054) Yang, C. (FULL: Seats=8, Open=0, Waitlist=0) Vishal Khandelwal, email: vishalk@glue.umd.edu

Tu........ 4:00pm- 7:00pm (AVW 1330) Lab

0106(24055) Yang, C. (FULL: Seats=8, Open=0, Waitlist=2) Ashwin Swaminathan, email: ashwins@umd.edu

M......... 4:00pm- 7:00pm (AVW 1330) Lab

 

·        Lecture time: Monday 2-2:50p.m., EGR 1108 CHM0119

·        Textbook: Microelectronics circuits by Sedra and Smith, 4th edition, or any other electronics circuit books, or online

·        Office: Room 1323, AVWII

·        Office hours: Monday 5-6p.m., and Wednesday 5-6p.m.

·        Phone: (301)405-3673; e-mail: yang@eng.umd.edu

·        Grading method: A=demonstrated knowledge in circuit analysis, convincing report, presentation, and successful operation of the final circuit; B= basically accomplished the same, but with a lesser degree, C=not clear about the circuit principle, circuit didn’t really work, but showed persistent effort, D=similar to C, only worse, and F=not much effort, no progress, no evidence of doing anything meaningful

·        Report: circuit diagram, pspice simulation, and your own analysis

·        Circuit1: stereo audio frequency preamplifier and power amplifier, with relatively high input impedance, low output impedance (<1ohm), a few Watts of output that can easily drive a pair of speakers

·        Circuit2: upon successful construction of the audio amplifier, for those interested we will supply you with other circuit ideas, such as RF transmitter, receiver, quartz clock, etc.

·        Circuit3: or, you may suggest other circuits --- we have to discuss and determine the cost, feasibility, time frame, expectation within this semester, etc.

·        Jan. 26, 2005 first day of class, Mar. 21-27 spring break, May 12 last day of classes

·        Final exam: Close-book, written exam., Thursday, May 19, 1:30 to 3:30p.m., EGR1108.

·        Design example (copied from “The art of electronics” by Horiwitz and Hill

·        Reports: Two reports are requested. One is due in the week of Feb. 14, 2005. This report must have (1) circuit schematics, (2) pspice analysis for dc currents and voltages everywhere, (3) pspice calculation for (a) amplitude and phase of the input impedance versus frequency, (b) amplitude and phase of the output impedance versus frequency, and (c) amplitude and phase of the voltage gain versus frequency. The amplitude plot should be in log-log scale, and the phase be in linear-log scale. One report per two-person team is due. You are to prepare a one-side transparency and present it in class on Feb. 14, 2005. We have a total of 16 design teams. So, prepare to speak for about 3 minutes sharp. The first 3 volunteers will get bonus points.

·        Specific issues about this first report

o       The goal of the pspice simulation is to get the circuit well-designed before you make the printed circuit board.

o       The input impedance needs to be large, much larger than the output impedance of the previous stage, which is about 600ohm. For example, 10kohm. The larger, the better.

o       The output impedance needs to be small, much smaller than the impedance of the load (~8ohm, speaker). The smaller, the better.

o       The open loop gain should be large, such as 100, so that the close-loop gain is controlled by the amount of feedback.

o       The close loop gain needs to be a fixed number, ranging from 10 to 20.

o       Your report summarizes your understanding to the problem and demonstrates your achievement.

o       The experimental results can be, should be, and in most cases will be accurately predicted by pspice simulation, within about 10-20 percent.

o       Verification --- see if you can produce the following results.

§         Do dc analysis to open loop circuit and see if the biasing to the transistors is as designed.

§         Do dc analysis to close loop circuit and see if the biasing to the transistors is as designed.

§         Then, do ac analysis

·        Transient analysis, with a large sine wave input, and see if the output still shows a constant gain until it is finally cut-off by the power supply limit.

·        Bode plots for input impedance, output impedance, and voltage gain.

o       Again, just a reminder: You have to understand how your circuit works now. Otherwise, you will face the same questions when you troubleshoot the soldered pc board.

o       The tone control is to be done by active filters with op-amps. That comes later, after the power amplifier is done.

 

·       Specific requirements in your final report

·        Introduction

o       What is this project? Define what it is that you are to build

o       Why bother? Of course you are asked to, but try to think of more positive reasons.

o       Other than building the power amplifier like what we are doing, is there a better way out there already?

·        Your circuit

o       Circuit diagram

o       Circuit simulation by pspice, including the (a) dc voltages, (c) dc currents, (3) frequency dependence of voltage gain, (4) frequency dependence of phase, (5) input impedance (both amplitude and phase) at difference frequencies, and (6) output impedance. Simulate across the audio frequency range from 100Hz to 20kHz. In fact, you should extend to be beyond this range, in order to display the reduction in response at very low and very high frequencies.

o       Your PC board layout

·        Experiment

o       Fabrication of the PC board (iron on the blue pattern, chemical etch, drill holes, soldering, etc.)

o       Observed facts:

§         (a) dc voltages,

§         (c) dc currents,

§         (3) frequency dependence of voltage gain,

§         (4) frequency dependence of phase,

§         (5) input impedance (both amplitude and phase) at difference frequencies, and

§         (6) output impedance.

§         (7) a photograph of your circuit?

Measure across the audio frequency range from 100Hz to 20kHz. In fact, you should extend to be beyond this range, in order to display the reduction in response at very low and very high frequencies. Describe for each item how you did the measurement, and then present data clearly. All figures should have labels, scales, units, and a figure caption. (Such as “Figure 3 shows the voltage gain versus frequency…”)

·        Discussion

o       Any specific observation about your circuit that you would like to put down for the record.

o       Particular drawbacks in the process?

o       Suggestions for future improvements about your circuit. For example, you would rather use JFET next time, not the bipolar transistors.

o       Suggestions for this laboratory experience. Too little challenge, or too much fun that you want to take it again?

 

Links:

·        Circuit etching technique: http://www.circuitspecialists.com/prod.itml/icOid/8097

·        The “blue paper” and application procedure: http://www.techniks.com/how_to.htm

·        Ferric chloride MSDS data sheet: http://www.jtbaker.com/msds/englishhtml/f1060.htm

·        Etching chemistry: http://www.artmondo.net/printworks/articles/ferric.htm

·        Do not pour ferric chloride down the drain: http://www.mgchemicals.com/techsupport/ferric_faq.html

·        Transistor characteristics: http://www.digikey.com

·        Printed circuit board layout program: http://www.cadsoft.de/ or many others that you can find online

·        Making PC board at home: http://www.users.bigpond.net.au/vk3yng/pcb/making_pcbs.htm

·        Ground loop issue: http://www.epanorama.net/documents/groundloop/index.html

·        Tin-lead eutectic point and the phase diagram: http://www.ce.berkeley.edu/~paulmont/CE60New/alloys_steel.pdf

·        Good soldering practice: http://www.elexp.com/t_solder.htm

·        Photos showing good soldered joints: http://www.epemag.wimborne.co.uk/solderpix.htm

·        Encyclopedia about soldering, PCB, and much more: http://users.pandora.be/educypedia/electronics/soldering.htm

·        Base-reflex speaker: http://hyperphysics.phy-astr.gsu.edu/hbase/audio/basref.html

·        Electro-static speaker: http://www.eskimo.com/~billb/esloud/eslhwto.html

·        Simple cross-over concept: http://hyperphysics.phy-astr.gsu.edu/hbase/audio/cross.html#c1

·        Cross-over example: http://www.audiocontrol.com/techpapers/techpaper102.pdf

·        Active versus passive crossover design: http://sound.westhost.com/biamp-vs-passive.htm#2.2

·        Encyclopedia about speakers: http://users.pandora.be/educypedia/electronics/loudspeakers.htm

 

Final reports

Working ones

 

 

Those showed good progress