Bias Circuit

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Chan2_in for reading for reading the base signal voltage. • GainSub.vi sends out bias and signal voltage (Chan1_out). (The signal is superimposed on the bias; the bias is modulated with signal.) Chan0_in reads the response (output of amplifier). The VI then resends the input signal (Chan1_out) and reads the response at the base (Chan2_in). These results are displayed in the two graphs. The ac peak values are used to calculate the gain. The VI also computes and displays rπ, βDC, and βac. • Open GainSub.vi. Set the Digital Controls for collector resistor, RC, base resistor, RB, and Rs. Rs is used to compute the signal current through Rs. Set Frequency at between 10 and 1000 Hz. Set VBB for 0.1 mA as determined with SetVCE.vi. VCC(init) must be less than or equal to 2 V. Default the Front Panel to hold these values for when GainSub.vi is used as a subVI. • Ratio VBB/Vs is set at 5. The VI uses this to set Vs = VBB/5, producing, roughly, IB/Ib = 5. This results from IB = (VBB – VBE)/RB and Ib = Vs/RB. This current ratio provides for operation in the linear mode. • Run GainSub.vi and verify IC 0.1mA. Verify that signals for Vbe = Vin and Vce = Vo appear to be undistorted (maintain sine-wave integrity). Assess all numbers in the Digital Indicators. At the low current of the measurement, Gain should be very close to gm·RC. Default and save the Front Panel to save settings for the next VI.
PC.4 Amplifier Gain versus <strong>Bias</strong> Current Procedure • Gain.vi is the main VI that obtains the voltage gain as a function of collector bias current. Open Gain.vi and verify that VBB(init) is set to your value for IC=0.1 mA and VBB/Vs=5. VCC(init) will be forced to 1 V in the execution of Gain.vi. Keep subVI GainSub.vi open to help observe the measurement in progress and to obtain Front Panel information for the maximum current. Verify that the correct data are defaulted in the Front Panel of GainSub.vi. The resistors values are not reset in the top VI. • Open 5COLDATA.vi. Open VIs using Browse>>Show VI Hierarchy from the main VI. • Run Gain.vi to obtain the gain for a range of collector current with maximum IC 1mA. Note that there is a 500 ms delay between bias steps to allow the capacitor to charge to steady state. Verify that Chan1_out(Max) (bias plus signal) does not exceed 10 V. Set the file mode switch to Get File. Run the VI to obtain a data file. • The data file includes results for IC, avb, βDC, and βac and rπ. The data provide for making a comparison between measured data and SPICE computations in the Mathcad project file. Default and save the Front Panel of 5COLDATA.vi for a data file backup. Default the Front Panel of Gain.vi to save the value of VBB for the maximum current. Default and save the Front Panel of GainSub.vi to save the value of VBE at the maximum current. • For obtaining a file from the saved data in Gain.vi, use GainData.vi. Transfer the data from the three Indicator Graphs of Gain.vi to the three equivalent Control Graphs in GainData.vi. Run GainData.vi to obtain the data file.
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Copyright Library of Congress Catal
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National Improvements | Virtual Ins
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formulations, the results from Math
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Hardware and Software Requirements
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Chan0_out Pin 21 Chan0_in Pin 68 Gn
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LabVIEW VI Libraries and Project an
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1.1 Resistor Voltage Divider and MO
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1.3 Frequency Response of the Ampli
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At f = flo, . This, by definition,
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1.5 Exercises and Projects Project
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2.1 BJT and MOSFET Schematic Symbol
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2.2 Fundamentals of Signal Amplific
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2.3 Basic NMOS Common-Source Amplif
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Using (2.4), (2.5), (2.9), and (2.1
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Unit 3. Characterization of MOS Tra
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In electronic circuit applications,
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The output-characteristic equation
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Equation 3.11 From the data measure
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The input circuit loop equation (Fi
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which leads to the result (3.5), re
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Unit 4. Signal Conductance Paramete
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4.2 Transistor Variable Incremental
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4.3 Transconductance Parameter The
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4.4 Body-Effect Transconductance Pa
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4.5 Output Conductance Parameter Th
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With a 1 - V drop across RS and a 5
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By the nature of the load-line func
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Unit 5. Common-Source Amplifier Sta
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5.2 Amplifier Voltage Gain This dc
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etween the drain and source of the
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5.3 Linearity of the Gain of the Co
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where av Vds/Vgs and where the appr
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is attached directly to the gate. B
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5.5 Design of a Basic Common-Source
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= VGSo - Vtno at the high and low e
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RG can be selected somewhat arbitra
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6.1 Grounded-Source Amplifier: Coup
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and Equation 6.6 Note that the "RC"
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6.4 Load Coupling Capacitor The com
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6.5 Summary of Equations MOSFET cou
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Unit 7. MOSFET Source-Follower Buff
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7.2 Source-Follower Voltage Transfe
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7.3 Body Effect and Source-Follower
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7.4 Summary of Equations Threshold
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Unit 8. MOSFET Differential Amplifi
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8.2 DC Imbalances In a real transis
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8.3 Signal Voltage Gain of the Idea
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8.4 Effect of the Bias Resistor on
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8.5 Differential Voltage Gain Suppo
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8.7 Voltage Gains Including Transis
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8.7.2 Common-Gate Amplifier Stage T
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with RD1 = RD2 and gm1 = gm2. In th
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It follows that the gain for the in
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8.9 Amplifier Gain with Differentia
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8.11 Summary of Equations Rs = Ris2
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9.1 Basic Current Source An example
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9.2 Current Source with Source Dege
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If the magnitude of the voltage acr
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Any slight possible difference in
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Unit 10. Common-Source Amplifier wi
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10.2 Signal Voltage Gain The expres
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10.3 Summary of Equations Output dr
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Unit 11. Operational Amplifiers wit
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11.1.1 Voltage Gain of the Noninver
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This expression can be manipulated
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11.3 Operational Amplifier Offset I
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where the approximation usually app
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where Avo is the amplifier gain at
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12.1 Operational Amplifier Integrat
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This demonstrates that for the circ
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with a steady-state value of Vop. A
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Equation 12.25 A good estimate come
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13.1 Combining NMOS and PMOS Circui
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13.3 Stabilization of Signal Gain a
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An estimate of the new output volta
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This produces (9.9) from Ro = Vo/Io
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Equation 13.13 where 13.12 has been
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The open-loop transconductance is G
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Unit 14. Development of a Basic CMO
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14.2 Current-Source Output Resistan
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14.3 Current-Source Load for the Co
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14.4 Current-Source Load for the Di
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the node (exclusive of the separate
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14.5 Two-Stage Amplifier with Curre
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14.6 Output Buffer Stage It is evid
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Suppose that ID6 = 400 µA, W6 = 50
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Av and Ro are calculated once, usin
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Since the source follower of M1 has
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14.9 Summary of Equations CMRR = 1
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Unit A. Communicating with the Circ
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Place AI Acquire Waveform.vi in the
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Click from the Front Panel or Diagr
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Now go to the Diagram (under Menu W
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To complete connections to the term
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Now use the Edit Text Tool to edit
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on the left in the diagram . The Wh
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Figure A.15. Frame of Sequence Stru
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The transition regions are nonabrup
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during the oscilloscope measurement
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Unit B. Characterization of the Bip
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junction diodes, the current is lar
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common to the input and output and
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B.2 Base-Width Dependence on Juncti
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Figure B.8. Diodelike characteristi
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The minus sign comes from having as
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Figure B.10. Circuit for measuring
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B.5 Output Characteristics of BJT i
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After measuring the output characte
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B.6 SPICE Solution for IC versus VC
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B.7 Collector-Emitter Voltage and C
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B.8 DC as a Function of Collector C
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B.10 Summary of Equations Common-em
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Unit C. Common-Emitter Amplifier St
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The equation set above has three un
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The output-resistance parameter, ro
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of βDC as possible. Signal paramet
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Equation C.17 We note that the magn
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C.4 Accuracy of Transistor Gain Mea
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C.5 Effect of Finite Slope of the T
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It follows that for this case, f3dB
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C.7 Common-Emitter Amplifier with A
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Equation C.41 where IC IC(VCE), tha
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Applied voltage Vo sums up to Equat
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C.7.3 DC (Bias) of the NPN - PNP Am
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where Equation C.58 and Equation C.
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Equation C.67 The result is signifi
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The following form of the result pr
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This is equivalent to a unity-gain
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C.11 Summary of Circuit Equations B
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C.12 Exercises and Projects Project
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P1.1 Resistor Voltage-Divider Measu
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• Place AO Update Channel.vi in F
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• (Optional) To install the circu
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Procedure • Set your value of RG2
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• In the Diagram, we will add Get
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P1.4 Resistor Voltage Divider with
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• Now move the capacitor C2 = C1
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P2.1 NMOS Common-Source Circuit wit
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• In the Diagram (below), place,
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P2.2 NMOS Common-Source Amplifier w
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P2.3 Amplifier with Signal and Gain
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• Connect to FG1Chan.vi, the vari
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P3.1 SPICE Parameters and Pin Diagr
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P3.3 PMOS Transistor Use pins 6 (ga
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Procedure • Run PMOSlinear.vi and
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Procedure • Run PMOSparsub.vi wit
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Procedure • Run PMOSparam.vi to r
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Active Region Procedure • Install
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Laboratory Project 4. Characterizat
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P4.2 NMOS Transistor Use CD4007 pin
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P4.4 NMOS Parameters from the Trans
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P4.5 NMOS Lambda from the Transfer
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P4.6 NMOS Gamma SubVI Components No
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• Set RS. With NMOSgamsub.vi open
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• A file can be obtained from the
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P5.1 SPICE Equations and Pin Diagra
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P5.3 Amplifier Gain at One Bias Cur
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P5.4 Amplifier Gain versus Bias Cur
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Laboratory Project 6. PMOS Common-
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P6.2 SPICE PMOS and Circuit Equatio
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P6.4 Amplifier Gain LabVIEW Computa
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P6.5 Amplifier Frequency Response P
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P7.1 Chip Diagram and SPICE Equatio
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P7.3 Amplifier Gain at Optimum Bias
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P7.4 Optimum Bias Stability Test
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P7.5 Amplifier Frequency Response P
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Laboratory Project 8. NMOS Source-
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P8.2 Source-Follower DC Evaluation
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available for the next VI. It is us
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Laboratory Project 9. MOSFET Differ
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P9.2 DC Evaluation of the Single-Po
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P9.3 Determination of the PMOS Para
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Gains will be obtained from the gra
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• Run SweepSim.vi to obtain the d
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Laboratory Project 10. Current Mirr
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P10.2 Evaluation of the Current-Sou
Page 373 and 374: P10.4 Evaluation of the Bias Setup
Page 376 and 377: Laboratory Project 11. Operational
Page 378 and 379: P11.2 Bias Circuit Setup 1 Offset N
Page 380 and 381: P11.3 Opamp Offset Voltage Componen
Page 382 and 383: P11.4 Evaluation of the Bias Balanc
Page 384 and 385: VOH • Reset the Chan0_out Range,
Page 386 and 387: P11.6 Evaluation of the Gain with S
Page 388 and 389: P11.7 Determination of the Opamp Fr
Page 390 and 391: Laboratory Project 12. Operational
Page 392 and 393: P12.2 Opamp Integrator Components R
Page 394 and 395: Procedure • Turn off the power su
Page 396 and 397: Laboratory Project A. Communicating
Page 398: PA.2 Sending and Receiving Voltages
Page 401 and 402: Bipolar TABLE PA.2 0 to +5V 1.22 mV
Page 403 and 404: PA.5 Observing the Oscilloscope Out
Page 405 and 406: of the DAC. The steps are 2.44 mV f
Page 407 and 408: • The example here illustrates th
Page 409 and 410: Laboratory Project B. Characterizat
Page 411 and 412: PB.2 SPICE Equations SPICE Equation
Page 413 and 414: parameters nF and IS. • Connect C
Page 415 and 416: PB.4 DC versus the Collector Curren
Page 417 and 418: • Now open VI, IC_VCE.vi. Set the
Page 419 and 420: Laboratory Project C1. NPN Common-
Page 421 and 422: PC.2 DC Circuit Setup and Parameter
Page 423: PC.3 Amplifier Gain at One Bias Cur
Page 427 and 428: • Run FreqResp.vi. Verify that in
Page 429 and 430: PC.6 SPICE Equations and Pin Diagra
Page 431 and 432: • Determine the value of VAF spec
Page 433 and 434: • Set the Run Mode switch to Set
Page 435: • Now reset VCC(init) and VBB(ini
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Bias Circuit

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