Electronic Devices and Circuits

ETE 305

Course Description:

Frequency dependent models for BJT and FET amplifiers, frequency effects upon gain and input-output impedance of single and multistage BJT and FET amplifiers, Bode plots, differential amplifiers.

Lab1- Biasing and Hybrid-Pi Model        2

Prelab:        2

Lab:        2

Part 1: DC        2

Part 1: AC        3

Post-lab:        4

Screenshots:        4

Lab 2 – Common-Emitter Amplifier with unbypassed Re        5

Prelab:        5

Lab:        6

Post-lab:        6

Screenshots:        7

Lab 3 BJT Single-Stage Amplifier Design        8

Prelab:        8

Lab:        9

Post-Lab:        10

Screenshots:        10

Lab 4 Single-Stage Amplifier Design (C.B.)        12

Pre-lab:        12

Lab:        12

Post-Lab:        13

Screenshots:        13

Lab 5        15

Pre-lab:        15

Lab:        15

Post-Lab:        15

Screenshots:        16

Lab 6 – Common-Emitter Amplifier Frequency Response        17

Pre-lab:        17

Lab:        17

Post-Lab:        19

Lab1- Biasing and Hybrid-Pi Model

Prelab:

IB= 6.67mA

R1= 169.5 kΩ

RE= 3 kΩ

R2= 61.67kΩ

RC= 6 kΩ

Lab:

Part 1: DC

Resistor Values (Actual)

Voltage Values (Actual)

R1= 159.9 KΩ

VCC= 15.01 V

R2= 62.2 KΩ

VBE=  0.66531 V

RC= 6 KΩ

VRC= 6.40 V

RE= 3.02 KΩ

Q-Point                       

VCEQ

5.3 V

IC

VRCRC=6.407 V6 K=1.07mA

𝛃DC

ICQIBQ=1 mA6=164     

𝛃AC

ΔICΔIB=1.8 Div x 0.2 mA2㎂=180

Part 1: AC

Values for Components

ƒ= 750 Hz

C1= 10 µF

Vs(p-p)= 30 mV

C2= 10 µF

VCC= 15.04

CE= 220 µF

Measured Values

IC= VRCRC=5.84V6K=0.97mA

Vi(p-p)= 29.9mV

Vo(p-p)= 51.9mV

rm= Vi(p-p)Vs(p-p)-Vo(p-p)Rs=29.9 mV30-29.9mV2k=598KΩ

Avs=Vo(p-p)Vs(p-p)=51.9mV30mV=1.73

Vo (with Ce)= 4.04V

Avs(with Ce)=Vo(p-p)Vs(p-p)=4.0430mV=134

Calculated Values

ri = 𝛃RE= 180(3.02K)= 543.6 kΩ

rm=ri ll RB= 543.6k ll 44.78 k= 41.37 kΩ

r𝜋= 𝛃rm= 180(41.37k)= 7.45 MΩ

Post-lab:

        This lab had two parts a AC and DC portion. We see that the capacitors are open in DC operation. We Find the Q point which is the transistors operating point. We than find the β using a curve tracer, because our β is actually different than what we used when we calculated the values for the prelab we see a noticeable difference in the values. In the second part we apply a AC signal to the transistor. We noticed that are values again are different with those that are calculated in that since our β is different than the actual it causes the gain to change. Using the oscilloscope, we measured the VI VO values, with and without a bypass capacitor.

Screenshots:

Without Ce capacitor                                                                   Measured Rin

https://lh6.googleusercontent.com/UeaaLjBcCm5_Bi3J2Jqu0zH1eoAovEbJWqBDZV_GOwbMLEokD8CYISK7rhIm6nQhiOSWNjtCLjEGWhuXGz8jIALytkI8MntQrZSfno5OLU-mWFFLEdydqmRSASC8oFYetAuw97tChttps://lh6.googleusercontent.com/Y2Nc7HEfFf6XTxpcJLrQbLDee19jSIzvXSyqfltFchwkQvXZJluV2vF8nLf_6PRl510X3zjbEkGr82or0AgLcaSpL2l_P-RQAm3sNnsWRagL-Ks1U4hDiIxNxEG6m-0Bs5Qz8lnO

With Ce capacitor

https://lh4.googleusercontent.com/wnLdCIUnlUjAYXkmsq3Me2BGOQjD8x4OAAJzeREYw8lX8iKWNlqcp7V0BvK4CAw55DtAdr2e_v-W9S-g26ryuwsu19ZO4I9k_MVXQu6v8h51CUnm_cW4uS1F-xM9tpfCCfzaVeKs

Lab 2 – Common-Emitter Amplifier with unbypassed Re

Prelab:

Ic= 1mA

VE = 3V

R1= 150k Ω

Vce= 6V

VB= 3.7V

R2= 59k Ω

Vcc= 15V

β= 150

RE = 3k Ω

RC = 6k Ω

rb = 44.6k Ω

rπ = 6.09M Ω

rm = 40.6k Ω

ri = 453k Ω

ro = ∞

Lab:

Actual Values                

RS= 9.814 kΩ

RC= 6.07 kΩ

RE1= 1.01 kΩ

CE= 220 uF

R1= 166.51 kΩ

C1= 10 uF

RE2= 2.2 kΩ

𝑓= 750 Hz

R2= 59.77 kΩ

C2= 10 uF

RL= 9.789 kΩ

VS= 85 mV

        

RE1 and RE2 Unbypassed

Measured Values

Vs

84 mV (see figure 1)

VCEQ

9.09 V

Avi = 1.5

Vi

200 mV (see figure 1)

ICQ

609.56 ㎂

Avs = 3.57

VL

300 mV (see figure 2)

rin = 25k Ω

Ais = 2.59

        RE2 Bypassed

Measured Values

Vs

84 mV (see figure 3)

VCEQ

9.09 V

Avi = 1.67

Vi

200 mV (see figure 4)

ICQ

609.56 ㎂

Avs = 5.95

VL

300 mV (see figure 3)

rin = 22.71k Ω

Ais = 2.3

Post-lab:

        Are results had some issues in places and none in others. Due to that the calculated and experimental values varied greatly and not at all. We got similar results when Re2 was bypassed when compared to the calculated values. This is most likely due to that the calculated values are not standard resistor values and so we had to choose resistors that were close to the value needed.

Screenshots:

figure 1                                                figure 2

https://lh4.googleusercontent.com/M0gmnM6OHNvzAnypEWoSXUbMq1R8v0Z3CeabOxM85dGxOvmCdQ84BHvzW_1Ru5fiGiTj9OyUDoGPykZU3O5MB-rCi2QHlFMwwXjj5GxfXBPBLPodbGqnyLLMKf_dnf9prMu7C5Hmhttps://lh6.googleusercontent.com/SYEs4SVS731iFtEG3r2QpNVuWnqpXuaLIhWe2VQ23Ec3Ln_FYR1E0e_zSQoMhexJcswyxcCm9NSDfFoLKB8-m2bQIeQVmzoLtV62dO1N65rs1sbqfZciaHQak6GNzoHuvIIeQoS9


figure 3                                                figure 4

https://lh4.googleusercontent.com/PnTTTpalKdYOfFTSe4vKAdntwCu-nYlwRlN5JF5zmodLg9VISZEiJt37E3YRGSsrvuzMakBZOrXfM7Xdukl28sYElMYAQuICTdATAVG_iQw3jtVsudURU9pLAIpnKzDPw4ZT7_xRhttps://lh5.googleusercontent.com/Vqwt3x2gYPnDr-fWk9hr9_d_7q4cbX2Oanr3m_cQD_Gfv5wlm55DObLty5JJvdjAjRn4kSVdMB7eTmXN75PqiKlv1pU4MHexOzA6rSFAMy52CNG_tCwYOOD3eZqQ2JEiwDRu8kQv


Lab 3 BJT Single-Stage Amplifier Design

image.jpg

Prelab:

No bypass

Avi = -1.24

rin = 45.23kΩ

RB = 45.23kΩ

ri =  759.5k

Ais = -48.23

RE & Re2 bypass

Re = 0

Avi = -144.23

Avs = -52.24

Ais = -83.29

Re2 Bypass

Re = 1k

Avi = -365

ri = 257.5k

rin = -2.9

Ais = -50.66

No Bypass

Re1 & Re2 Bypass

Re2 Bypass

Avs

-1.004

-52.24

-2.9

Avi

-1.24

-144.23

-3.65

rin

42.69k

5.68k

38.47k

Ais

-48.23

-83.29

-50.66

Re1 = 1k

Re2 = 2k

Lab:

Actual values

RS= 988.3 Ω

C1= 10µF

RE= 816.4 Ω

R1= 11.972 kΩ

CE= 220µF

RL= 996.2 Ω

R2= 15.768 kΩ

𝑓= 5 kHz

VS= 500 mV

Measure Q-Point { ICQ, VCEQ }

VCEQ

9.5 V

ICQ

VRERE=6.3 V816.4 Ω =7.716 mA

Measure Vi , VL, VS

Vs

500 mV (see figure 1)

Vi

420 mV (see figure 2)

VL

409 mV (see figure 1)

Calculate Avs , Ais , rm

Avs

VLVS=409 mV500 mV = 0.818

rm

VSIS-Rs=500 mV80.95 µA-988=5.188kΩ

Ais

ILIS=410.56µA80.95µA=5.07

Post-Lab:

  1. Calculate rX

rx

𝛃(rLAV-rl-rm)=

(180)(448.690.818-448.69-3.369)

= 17.36 kΩ

  1. There was some usual variation between the measured values and the calculated values due to that of the actual components. Mainly the difference was caused by the Beta of the transistor where we assumed that beta was 150 when our actual beta was not. Thus giving us the most error within out data.
  2. As always calculations vary than actual results, but in order to get less error it would be better to use more accurate numbers for calculations such as resistor value and transistor beta.

Screenshots:

Figure 1

https://lh5.googleusercontent.com/KLd7YgPyN39DDdxYrqQNpCJt2L_OyY7DBF_DXAV6OKSIwxKpDmjymEDwBpAs_GnHlsPaiKDNoh50SeGzYLKgYNPj9WXzb5Dwnf4SkLQucctyevnWj7HLIFK65Me24tHTXiy5aZUL

Figure 2

https://lh3.googleusercontent.com/73pNJVlbyhPB1mliPdOljfLfvL7hZLgvhR9LGxDfYPB_6neFIUN5kDmBE3y0oPUVpi6xoak0DuTVjYQ8F6ej0b4tv0MxR0SQawmwUrqRDD0_scm2AO4MD8Dai6_TsCMAeViwO-i2


Lab 4 Single-Stage Amplifier Design (C.B.)

Et 305e lab 4 - EveryCircuit

Pre-lab:

VTH = 5v

RTH = 3.75k

IB = 5.22µA

Ic = .856mA

rm = 30.37Ω

rπ = 5.4627k Ω

rin = 30.1867 Ω

rL = 476.19 Ω

Av = 15.68

Avs = 0.8

rc = 909.09 Ω

Av = 29.96

Ais = 0.878

Lab:

Actual Values

RS= 53 Ω

C1= 1µF

R1= 15 kΩ

CE= 1µF

R2= 5.5 kΩ

𝑓= 1 kHz

RC= 10.2 kΩ

VS= 100 mV

RE= 5.5 kΩ

RL= .98 kΩ

Measured values

Vs(p-p)

98 mV

VCEQ

VRC= 8.61 V

Is(p-p)

1.28 mA

Vi(p-p)

30 mV

ICQ

8.44 mA

IL(p-p)

1.22 mA

VL(p-p)

1.2 V

AVS

122.4

VL1

4.8 V

AIS

0.953

VL2

30 mV

RIN

23.44Ω

ROUT

159 KΩ

Post-Lab:

        The values gathered from pre-lab is what we used to determine the values for the circuit. Due to that they actual values were different than the calculations would give us a typical error. However, the measured values turned out to be pretty off. The reason for this I am still not sure of either we did the calculations wrong or we measured/ read the measurements incorrectly.

Screenshots:

https://lh3.googleusercontent.com/gOFWUssH0IvV887SurS_W7uBsCfBDX5USzOfbFsNV5XEgVB7KpJCI49hG-ErGUXRHaLfmbRBv6cMvbbjzjqbx1ejuA0a7o3vMOdO8cALxl3B_AuluytPZTQ6rlAiAnQPNXtBhp2qhttps://lh3.googleusercontent.com/HVogDHg6fKOrZd6NeWeAnRWT7a9xPRIU-mtHzBY7Nl5Ne2zlhiKtoVSud-94HT_htOMGfzzfUL9zfvvmSBBG7CO0081CNDBh0CkBfugrs2rzlORTulholD3nLd28Qoj5sbfuwDIB

https://lh3.googleusercontent.com/tSBAngHgvIbdmZe4jl6S9RbSsc6k03RTW_ZRMf9QoVyUSdfKsef_KQJ3eQXi-GW50dnWTzxC1Gb0kY8UuuEOA_NfR8dOQoETnGeRtZ9e-yJIVevEiZaIF3DrtkCCwv6W-qNKetUJhttps://lh3.googleusercontent.com/vmANjSN7GeS30l4rF1AHtqDA78nw0RIUTFPTIofj3QAKOVxdphbfzUp11ymRD1KF0yVIKVlJmzhq2hvbWnkzn1ybGoMRwMxHi5pnvOOAgh_EObCAWoybT_x6qDTK04ZxBnFM8u94


Lab 5

Lab 5 - EveryCircuit

Pre-lab:

        No prelab

Lab:

https://lh4.googleusercontent.com/U0wpo9xJLquOaNswsmmArtKhKUqMZiizY-ZJHhP0VoZB1OyRGqq7ANfkPIf912n5k7gRHuQ579wSdazoTT6FpMWtqjmmL4hWOSBCM5BIA12kv5RkqB9k9_dafMlBq2gJJvhYxYWQ

Post-Lab:

        We could not get the circuit to work at first, at least we thought we couldn’t. We realized that the circuit was working it was just that are transistor was below cutoff frequency and so the transistor was not active. As we began to increase the frequency the numbers started to get better and mare more sense. We found our midband frequency was about 500kHz after taking enough data points and making the bode plot.

Screenshots:

https://lh6.googleusercontent.com/EJdpc81pNUat-ss5nAVde9Fcbg6QoLeScFf8_3-w6dHagWkNSRhsLtqg6VruxpjDdQy0HnhV39QHjOJ_6MqMbHf_v3h5KDqAs-6rsb-hSRpArsjBNJaHmc6yRduPbbOAUR7A9VZPhttps://lh3.googleusercontent.com/Y4t_7tPJLQxvhxZfVZhT-b05SNkqAJQjfrbV2AFuM5HP17kfEourDtrS7psY7yLFJC-dLo2zCtJ9FinzSyznz-SSJHxam5HXD7LaL9Gde1qd49Zk1gltQkDOsla0d-G1PH0rQ60Ihttps://lh5.googleusercontent.com/_SLfLcCzB24NTsKNLeDX4_5lEWV0rbmrhA-eDQ_kxSqpy2D93XiDlz5XumIQpBGrRQxSSrcowOkW9Da3z2824Pkms_p7owU73u0ym-EsX_asI8qvfXEZr8pliLuWUoNTtSEAEyxR


Lab 6 – Common-Emitter Amplifier Frequency Response

Lab 5 - EveryCircuit

Pre-lab:

rB= 50 kΩ

rM= 1.73 Ω

ri= 3.28 kΩ

AVS= -2.6

IB= 100µA

rπ= 260 Ω

rin= 3.08 kΩ

𝑓 1= 1Hz

IC=  15mA

ro= ∞  Ω

AV= 3.45

Lab:

Change C and measure VDS to calculate ID. Plot      Change VDD and measure VDS to calculate ID. Plot

 

Use Curve Tracer to find IDSS  = 10.2mA

Post-Lab:

        Find ID  = ID=IDSS[1-(-RsID)/Vp]^2 = .05mA

https://lh3.googleusercontent.com/AOHqJtbjJcYlvpATSFxGftmXsq1gBhrUYcwP4v9C6UM4unXhVCaQs-D97UcvcoAINkGsTIigt4TOwwqdKZAQ-jD6jtZ77OHnQyg1ola3HUQvdKNPLnePgc1_U8AP4YMaLSlpwfFBhttps://lh4.googleusercontent.com/Oc5LNmasVQqmePuPNYjInxaUsnPky28XeDtyBxIoohuwtnDL59yyw2oTbxm8wCkJqWGykcCURpyjAtzo8wS4V770d7HkRI85VaeYYin7IzaKAuIzeNhC_E604NWlJACPagtTScLY

Our results are quite the same with the theory of amplifier response and the low frequency characteristics of a common-emitter BJT amplifier. We had a bit of trouble at the beginning but we managed to get it to work in the end.