ELEC 2000 Semiconductor Devices Homework #1 Choose the answer that best completes the statement or answers the question. (1) Assume the valence electron is removed from a copper atom. The net charge of the atom becomes a. 0 b. +1 c. -1 d. +4 (2) The valence electron of a copper atom experiences what kind of attraction toward the nucleus? a. None b. Weak c. Strong d. Impossible to say (3) How many valence electrons does a silicon atom have? a. 0 b. 1 c. 2 d. 4 (4) Silicon atoms combine into an orderly pattern called a a. Covalent bond b. Crystal c. Semiconductor d. Valence orbit (5) An intrinsic semiconductor has some holes in it at room temperature. What causes these holes? a. Doping b. Free electrons c. Thermal energy d. Valence electrons (6) The merging of a free electron and a hole is called a. Covalent bonding b. Lifetime c. Recombination d. Thermal energy (7) At room temperature an intrinsic silicon crystal acts approximately a. A Battery b. A conductor c. An insulator d. Copper wire (8) The amount of time between the creation of a hole and its disappearance is called a. Doping b. Lifetime c. Recombination d. Valence (9) A conductor has how many type of flow? a. 1 b. 2 c. 3 d. 4 (10) A semiconductor has how many types of flow? a. 1 b. 2 c. 3 d. 4 (11) For semiconductor material, its valence orbit is saturated when it contains a. 1 electron b. Equal (+) and (-) ions c. 4 electrons d. 8 electrons (12) In an intrinsic semiconductor, the number of holes a. Equal the number of free electrons b. Is greater than the number of free electrons c. Is less than the number of free electrons d. None of the above (13) The number of free electrons and holes in an intrinsic semiconductor decreases when the temperature a. Decreases b. Increases c. Stays the same d. None of the above (14) The flow of valence electrons to the right means that holes are flowing to the a. Left b. Right c. Either way d. None of the above (15) Holes act like a. Atoms b. Crystals c. Negative charges d. Positive charges (16) An donor atom has how many valence electrons? a. 1 b. 3 c. 4 d. 5 (17) If you wanted to produce a p-type semiconductor, which of these would you use? a. Acceptor atoms b. Donor atoms c. Pentavalent impurity d. Silicon (18) Electrons are the minority carriers in which type of semiconductor? a. Extrinsic b. Intrinsic c. n-Type d. p-type (19) Silver is the best conductor. How many valence electrons do you think it has? a. 1 b. 4 c. 18 d. 29 (20) Which of the following describes an n-type semiconductor? a. Neutral b. Positively charged c. Negatively charged d. has many holes (21) What is the barrier potential of a silicon diode a room temperature? a. 0.3 V b. 0.7 V c. 1 V d. 2 mV per degree Celsius
Design of Electrical Systems Name: ______________________________ Note: All problems weighted equally. Show your work on all problems to receive partial credit. Resources: a) The Fundamental Logic Gate Family, Author Unknown b) Electric Devices and Circuit Theory 7th Edition, Boylestad c) Introductory Circuit Analysis 10th Edition, Boylestad d) Power Supplies (Voltage Regulators) Chapter 19, Boylestad e) Electronic Devices and Circuit Theory Chapter 5, Boylestad f) Operational Amplifiers Handout, Self g) Switch Mode Power Supplies, Philips Semiconductor h) NI Tutorial 13714-en October 6, 2013 i) NI Tutorial 13714-en V2.0 October 6, 2013 j) National Instruments Circuit Design Applications http://www.ni.com/multisim/applications/pro/ k) ENERGY STAR https://www.energystar.gov/index.cfm?c=most_efficient.me_comp_monitor_under_23_inches l) Manufactures Device Data Sheets 1) For the VDB shown below, please find the following quantities and plot the load line (Saturation / Cutoff), Q pt (Quiescent Point) and sketch input waveform and output wave form. Remember to test for Exact vs. Approximate Method. Given Bdc = hfe = 150 and RL of 10KΩ. Efficiency _ Class _____ Degrees ___ VR2_______ VE_______ VC _______ VCE ______ IC _______ IE _______ IB _______ PD _______ re’ _______ Av _______ mpp ______ Vout______ What is the effect of reducing RL to 500Ω ________________________________ What is the effect of reducing the Source Frequency to 50 Hz ________________ | | | | | | |____________________________________________ 2) For the following Networks, please complete the Truth Tables, Logic Gate Type, provide the Boolean Logic Expression. A | Vout 0 | 1 | Logic Gate Type _______ Boolean Logic Expression _________ A B| Vout 0 0| 0 1| 1 0| 1 1| Logic Gate Type _______ Boolean Logic Expression _________ A B C| Vout 0 0 0| 0 0 1| 0 1 0| 0 1 1| 1 0 0| 1 0 1| 1 1 0| 1 1 1| Logic Gate Type _______ Boolean Logic Expression _________ Operation of Transistors ____________ 3) For the Network shown below, please refer to Electronic Devices and Circuit Theory Chapter 5, Boylestad to solve for the following values: Given: Bdc1 = hfe1 = 55 Bdc2 = hfe2 = 70 Bdc Total ______ IB1 _________ IB2 _________ VC1 __________ VC2 __________ VE1 __________ VE2 __________ What is this Transistor Configuration? _______________________ What are the advantages of this Transistor Configuration? _________________________________________ _________________________________________ _________________________________________ _________________________________________ 4) Design a Four (4) output Power Supply with the following Specifications, Provide a clean schematic sketch of circuit (Please provide the schematic sketch on a separate piece of graph paper). Use a straight edge and label everything. Refer to Data Sheets as necessary. Specifications: 120 VAC rms 60 Hz Source Positive + 15 VDC Driving a 15Ω 20 Watt Resistive Load Positive +8 VDC Driving a 10Ω 2 Watt Resistive Load Negative – 12 VDC Driving a 10Ω 2 Watt Resistive Load Negative – 5 VDC Driving a 4Ω 2 Watt Resistive Load Parts available (Must use parts): 1x 120 VAC 40 Volt 3.5 Amp Center Tap Transformer 1x Fuse 1x Bridge Rectifier 12 Amp 1x LM7808 1x LM7815 1x LM7905 1x LM7912 Psource _____________ Fuse size with 25% Service Factor, 1-10 Amps increments of 1A, 10 – 50 Amps increments of 5 Amps ______ Are we exceeding Power Dissipation of any components? If so please identify and provide a brief explanation: _________________________________________________________________ _________________________________________________________________ 5) For the circuit shown below please calculate the following quantities, and Plot the Trans-Conductance Curve (Transfer Curve), (Please provide the plot on a separate piece of graph paper): You will need to refer to the 2N3819 N-Channel JFET ON Semiconductor Data Sheet Posted on Bb. VDS _________ VP ___________ VGS(off) ______ VS __________ VD __________ VG __________ PDD _________ PSource ______ VGSQ ________ IDQ __________ 6) Determine both the Upper and Lower Cutoff frequencies. Sketch Bode plot and label everything including dB Role-Off. Construct Network in Multisim and perform AC Analysis verifying frequency response and Upper and Lower Cutoff Frequencies in support of your calculations. Attach Screen shot of your Multisim Model and AC Analysis. Repeat the above for a 2nd Order Active BP Filter. You will need to research this configuration. Make sure that you use the same values for R and C. Upper and Lower Cutoff Frequencies are determined by for the 2nd Order Active BP Filter fc = 1/(2(3.14)SQRT(R1R2C1C2)). Demonstrate a change in Roll-Off from 1st Order to 2nd Order. First Order: Lower Cutoff Frequency ________ Upper Cutoff Frequency ________ Roll-Off ______________________ | | | | | | | |_____________________________________________________________ Second Order: Lower Cutoff Frequency ________ Upper Cutoff Frequency ________ Roll-Off ______________________ | | | | | | |_____________________________________________________________ 7) The following questions relate to LED Backlight LCD Monitors. (Please feel free to use more paper if need be). See Resources. Please explain the differences between LED Backlight LCD Monitor, LCD and CCFL Monitors (Cold Cathode Fluorescent Lamp) Monitors. What are some advantages of LED Backlight LCD Monitors when compared with LCD and CCFL Monitors? What color LEDs are used in the creation of an LED Backlight LCD Monitor? Does a Black Background use less energy than a White Background? If you can believe the hype, how and why are LED Backlight LCD Monitors among the most energy efficient, higher than heirs apparent? 8) In this problem the goal is to verify the Transfer Characteristics of the 2N7000G Enhancement Mode N-Channel MOSFET against the manufactures Data Sheets. Please create in Multisim a Model as exampled below. First Plot by hand on Graph Paper various VGS Voltages vs ID. Second simulate using the DC Sweep Analysis. From these results verify against the 2N7000G ON Semiconductor Data Sheet Posted on Bb, remembering that the 2N7000G ON Semiconductor Data Sheet includes both Tabulated Data and Figure 2. Transfer Characteristics. Attach all results, screen shots and write a brief description of your work. • I estimate that my mark for this exam will be: ________ % • Time spent on this exam: __________ Hours • Average of time spent per week on work for EGR-330 (outside class sessions): ______________ Hours
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Biomedical Signal and Image Processing (4800_420_001) Assigned on September 12th, 2017 Assignment 4 – Noise and Correlation 1. If a signal is measured as 2.5 V and the noise is 28 mV (28 × 10−3 V), what is the SNR in dB? 2. A single sinusoidal signal is found with some noise. If the RMS value of the noise is 0.5 V and the SNR is 10 dB, what is the RMS amplitude of the sinusoid? 3. The file signal_noise.mat contains a variable x that consists of a 1.0-V peak sinusoidal signal buried in noise. What is the SNR for this signal and noise? Assume that the noise RMS is much greater than the signal RMS. Note: “signal_noise.mat” and other files used in these assignments can be downloaded from the content area of Brightspace, within the “Data Files for Exercises” folder. These files can be opened in Matlab by copying into the active folder and double-clicking on the file or using the Matlab load command using the format: load(‘signal_noise.mat’). To discover the variables within the files use the Matlab who command. 4. An 8-bit ADC converter that has an input range of ±5 V is used to convert a signal that ranges between ±2 V. What is the SNR of the input if the input noise equals the quantization noise of the converter? Hint: Refer to Equation below to find the quantization noise: 5. The file filter1.mat contains the spectrum of a fourth-order lowpass filter as variable x in dB. The file also contains the corresponding frequencies of x in variable freq. Plot the spectrum of this filter both as dB versus log frequency and as linear amplitude versus linear frequency. The frequency axis should range between 10 and 400 Hz in both plots. Hint: Use Equation below to convert: Biomedical Signal and Image Processing (4800_420_001) Assigned on September 12th, 2017 6. Generate one cycle of the square wave similar to the one shown below in a 500-point MATLAB array. Determine the RMS value of this waveform. [Hint: When you take the square of the data array, be sure to use a period before the up arrow so that MATLAB does the squaring point-by-point (i.e., x.^2).]. 7. A resistor produces 10 μV noise (i.e., 10 × 10−6 V noise) when the room temperature is 310 K and the bandwidth is 1 kHz (i.e., 1000 Hz). What current noise would be produced by this resistor? 8. A 3-ma current flows through both a diode (i.e., a semiconductor) and a 20,000-Ω (i.e., 20-kΩ) resistor. What is the net current noise, in? Assume a bandwidth of 1 kHz (i.e., 1 × 103 Hz). Which of the two components is responsible for producing the most noise? 9. Determine if the two signals, x and y, in file correl1.mat are correlated by checking the angle between them. 10. Modify the approach used in Practice Problem 3 to find the angle between short signals: Do not attempt to plot these vectors as it would require a 6-dimensional plot!
Que 1: true of false a) Both silicon and germanium atoms have four valances electrons b) When forward-biased , a diode has a very high resistance c) A zener diode is designed to operate in the forward-bias region and has higher reverse breakdown voltage level than regular diode Write the word or phrase that best completes each statement or answers the questions: d) In semiconductor, in addition to the electron flow, there is also another kind of charge flow referred as………………. e) A silicon diode in placed in series with 2kΩresistor and a 14 V dc power supply. The current ID is: i) 6.65 mA ii) 2.2 mA iii)7.5 mA iv) 14 mA f) The series resistor that limits the forward current length through a silicon diode to 8 mA if the power supply voltage is 9.5V is : i) 1.1 kΩ ii) 2.2 kΩ iii) 9.5 mA iv) 4.7 mA FIGURE g) Determine the diode current IZ for the circuit of figure 1-2: assume VZ = 3.9 V i) 8.1 mA ii) 3.55 mA iii) 24.5 mA iv) 13.64 mA h) Determine the current through a 20 mA yellow LED when the power supply voltage is 15 V the series resistor is 2k ohm and the diode is put in backward. Assume VLED = 2V i) 20 mA ii) 0 mA iii) 10 mA iv) 6.5 mA Write the word or phrase that best completes each statement or answers the questions: i) Zener diode is a p-n junction diode that is desgined for specifc…………………voltage j) ………………………….is the process by which impurity atoms are introduced to the instrisic semiconductor in order to alter the balance between holes and electrons. 1) The average value of s full-wave rectifier with a peak vaue of 17V ia 108V 2) If the frequency of input signal of the full wave reflector is 60Hz, the output frequency is 120Hz 3) The cathode of a zener diode, when conducting is:y i) at 0.7V ii) more positive than anode iii) more negative than anode iv) -0.7V 4) A given transformer with turn ratio 12:1has an input of 115V at 60Hzthe paek output voltage v0 (p) is i) 9.58 V ii) 6.78V iii) 11.5 V iv) 13.55 V FIGURE 2-1 5) The output voltage of V0(DC)for the full wave rectifier of figure 2-1 is i) 18.07 V ii) 12.78 V iii) 8.3 V iv) 5.74 V FIGURE 2-2 6) The voltage V2(P) for the full-wavr bridge rectifier of figure 2-2 is i) 17.37 V ii)1 6.67 V iii) 12.78 V iv) 18.07 V 7) Assume the current I0(DC) in figure is 100mA and C= 2400µF .the ripple voltage vr (p-p) i) 694mV ii) 424 mV iii) 121 V iv) 347 V Use figure 2-3 for questions below: Assume that RS = 75, RL = 160 FIGURE 2-3 8) The output voltage V0 is i) 7.5 V ii) 10 V iii) 8.5 V iv) 12 V Write the word or phrase that best completes each statement or answers the questions: 9) The magnitude of the peak-to-peak ripple voltage vr (p-p) is directly proportional to the output …………………. 10) The ripple voltage at the filter section vr (p-p) can be reduced by increasing the value