代写Design a diode代写数据结构语言
- 首页 >> OS编程(Part I, 1) Design a diode
0. Run the simulation software TCAD; select the process file DIODE.IN
1. Start with a silicon wafer
1 x 1015 atoms/cc, boron doped <111> substrate
2. Fabricate a P/N diode
Adjust the dose and drive-in time of the N-type implant (using phosphorus) to achieve:
(i) junction depth = (300 + last two digits of your student number) nanometers
(ii) maximum concentration of the N-region = 5 x 1018 atoms/cc
(N.B. all specific quantities to be designed within 5 %).
3. Extract the parameters of the diode (with a cross-sectional area of 1 mm x 1 mm)
From the simulated I-V curve of the diode, extract the saturation current Is (in ampere) for reverse bias and the maximum slope of loge(I)-V curve for forward bias.
Also, based on the text file c:\elec2303\tcadwork\diode.iv, calculate the zero-biased junction capacitance Cj0 (in Farad) and series resistance Rs (in ohm for a wafer thickness of 500 um) of the diode.
(N.B. sheet resistance of a p- or n-type layer is related to horizontal current flow in the layer, while Rs is related to vertical current flow through the wafer)
(Part I, 2) Design a radio receiver
(AM: 540 ~ 1610 kHz, with 10 kHz spacing; Telephony: 0 ~ 3 kHz)
1. Use the above diode for the radio receiver below
In the program Schematics (of PSPICE), the top menu bar has these buttons:
1. Get New Part – select components (R, C, L, Dbreak)
2. Draw Wire – connect the components to build a circuit
3. Voltage Marker / Current Marker – monitor voltage / current in the circuit
4. Setup Analysis – select analysis type
5. Simulate – start simulating the circuit
Use them to draw the radio receiver without the antenna and earphone.
(i) Set the parameters of the diode.
Select the diode named Dbreak.
In the Edit button, select "Model".
Select "Edit Instance Model".
Set Rs and Cjo = 0.
Set Is (in ampere).
(ii) For the coil, the *T of its tap points indicates the number of turns w.r.t. the ground. Model the coil by 3 inductors (with inductance proportional to the number of turns and a coupling constant of 1) and a series resistance of 0.1 Ω.
The coupling is created by placing a component ‘K_Linear’ anywhere in the circuit schematic and applied to the inductors by adding their names inside the component (double-click it)
(iii) An AM radio wave (= audio signal * carrier wave) induces a voltage in the antenna.
Model the antenna by a multiplier (“MULT”) with
input 1 = sin(2π × 106 t) volt
input 2 = 0.1 sin(2π × 3 × 103 t) volt
(iv) Calculate the total inductance of the coil for tuning to the AM radio wave.
2. Use PSPICE to simulate the radio receiver
(In “Setup Analysis”, choose “Transient”)
(i) Comment on the output waveform. of the radio receiver.
(ii) Vary the cross-sectional area of the diode and explain its effect on the output waveform. (Double-click the diode. Input the value for AREA, with 2 meaning doubling the area)
(iii) By adding Rs (in ohm) in the diode model, repeat (i) and (ii).
(iv) By adding Cjo (in Farad) in the diode model, repeat (i) and (ii).
(v) By adding both Rs and Cjo in the diode model, get the optimal size for the diode.
(Part II, 1) Design a bipolar transistor
1. Fabricate a bipolar transistor
Add a boron implant to the diode in Part I to form. a P+/N/P structure,
and then add a heating step at 900 C in nitrogen ambient for 30 minutes.
Vary the energy (keV) and dose (atoms/cm2) of the implant to achieve
(i) P+/N junction depth = (300 + last two digits of your student number)/2 nm
(ii) maximum concentration of the P+ region = 1 x 1020 atoms/cc.
(N.B. all specific quantities to be designed within 5 %).
2. Extract the parameters of the transistor
After extraction, the parameters of the BJT (with a cross-sectional area of 1 cm x 1 cm) are stored in a text file:
diode.pnp in c:\elec2303\tcadwork
(e.g. IS = saturation current, BF = current gain, CJE = capacitance of B-E junction under zero bias)
(Part II, 2) Design an amplifier for the radio receiver
1. Use the above bipolar transistor for the amplifier below
(i) set the supply voltage VCC = -5 V.
(ii) adjust RB so that the quiescent (Q) point is at the middle of the load line.
(iii) hybrid-pi model of the bipolar transistor: calculate the input resistance (= VT/IB) and transconductance (= IC/VT) [VT = thermal voltage, IB and IC for the Q point]
(iv) assuming infinite output resistance for the transistor and source resistance RB1 = 0, calculate the voltage gain of the amplifier.
2. Use PSPICE to simulate the amplifier
(0) cross-sectional area of the transistor = 1 mm x 1 mm
(i) select the blank PNP transistor named QbreakP. Then, set its parameters as the extracted parameters of the transistor designed above by:
Select the transistor.
In the Edit button, select "Model".
Select "Edit Instance Model".
Copy and past the parameters in diode.pnp (remove all “+”) after the 1st line.
Double-click the transistor.
Input the value for its cross-sectional area AREA (in cm2).
(ii) for the input signal V1 in the diagram, simulate the voltage gain and compare with the value calculated above.
(In “Setup Analysis”, choose “Transient”)
(iii) simulate the Total Harmonic Distortion (THD) of the output signal
(In “Transient…”, enable “Fourier Analysis” and specify the fundamental frequency of the signal you want to analyze)
(iv) explain the simulated effects of the amplitude of the input signal on the voltage gain and THD.
(v) simulate the frequency response of the amplifier (In “Setup Analysis”, choose “AC Sweep”), and explain the shape of the curve.