Revision as of 22:42, 8 March 2011

DC Bipolar Transistor Curves

Transistor circuit

1.) Identify the type (n-p-n or p-n-p) of transistor you are using and fill in the following specifications.

Value	Description
	Collector-Base breakdown voltage
	Emitter-Base Breakdown Voltage
	Maximum Collector Voltage
	Maximum Collector Current
	Transistor Power rating([math]P_{Max}[/math])
	DC current gain [math]h_{FE}( I_C, V_{CE})[/math]

2.) Construct the circuit below according to the type of transistor you have.

3.) Measure the emitter current [math]I_E[/math] for several values of [math]V_{CE}[/math] by changing [math]V_{CC}[/math] such that the base current [math]I_B = 2 \mu[/math] A is constant.

V_{CC}	V_B	V_ E	I_B	I_E

4.) Repeat the previous measurements for A. Remember to keep [math]I_CV_{CE} \lt P_{max}[/math] so the transistor doesn't burn out

5.) Graph [math]I_C[/math] -vs- [math]V_{CE}[/math] for each value of [math]I_B[/math] and [math]V_{CC}[/math] above. (40 pnts)

6.) Overlay points from the transistor's data sheet on the graph in part 5.).(10 pnts)

Questions

Compare your measured value of [math]h_{FE}[/math] or [math]\beta[/math] for the transistor to the spec sheet? (10 pnts)
What is [math]\alpha[/math] for the transistor?(10 pnts)
The base must always be more _________(________) than the emitter for a npn (pnp)transistor to conduct I_C.(10 pnts)
For a transistor to conduct I_C the base-emitter junction must be ___________ biased.(10 pnts)
For a transistor to conduct I_C the collector-base junction must be ___________ biased.(10 pnts)

Forest_Electronic_Instrumentation_and_Measurement

@@ Line 1: / Line 1: @@
-The Common Emitter Amplifier
+DC Bipolar Transistor Curves
-=Circuit=
-#Construct the common emitter amplifier circuit below according to your type of emitter.
+[[Media:2N3906.pdf]]
-#Calculate all the R and C values to use in the circuit such that
-##<math>I_C > 0.5</math> mA DC with no input signal
+[[File:2N3906_PinOuts.png]]
-##<math>V_{CE} \approx V_{CC}/2 > 2</math> V
-## <math>V_{CC} < V_{CE}(max)</math> to prevent burnout
+=Transistor circuit=
-## <math>V_{BE} \approx 0.6 V</math>
+.) Identify the type (n-p-n or p-n-p) of transistor you are using and fill in the following specifications.
-##<math>I_D \approx 10 I_B < 1</math> mA
-#Draw a load line using the <math>I_{C}</math> -vs- <math>I_{CE}</math> from the previous lab 13.  Record the value of <math>h_{FE}</math> or <math>\beta</math>.
-#Set a DC operating point I^{\prime}_C so it will amplify the input pulse given to you.  Some of you will have sinusoidal pulses others will have positive or negative only pulses.
+{| border="1"  |cellpadding="20" cellspacing="0
-#Measure all DC voltages in the circuit and compare with the predicted values.(10 pnts)
+|-
-#Measure the voltage gain <math>A_v</math> as a function of frequency and compare to the theoretical value.(10 pnts)
+|Value || Description
-#Measure <math>R_{in}</math> and <math>R_{out}</math> at about 1 kHz and compare to the theoretical value.(10 pnts)
+|-
-#Measure <math>A_v</math> and <math>R_{in}</math> as a function of frequency with <math>C_E</math> removed.(10 pnts)
+| || Collector-Base breakdown voltage
+|-
+| || Emitter-Base Breakdown Voltage
+|-
+| || Maximum Collector Voltage
+|-
+| || Maximum Collector Current
+|-
+| || Transistor Power rating(<math>P_{Max}</math>)
+|-
+| || DC current gain <math>h_{FE}( I_C, V_{CE})</math>
+|}
+.) Construct the circuit below according to the type of transistor you have.
+[[File:TF_EIM_Lab13_Circuit.png | 200 px]]
+.) Measure the emitter current <math>I_E</math> for several values of <math>V_{CE}</math> by changing <math>V_{CC}</math> such that the base current <math>I_B = 2 \mu</math> A is constant. <math>I_B \approx \frac{V_{bb}-V_{BE}}{R_B}</math>
+{| border="1"  |cellpadding="20" cellspacing="0
+|-
+|V_{CC} || V_B || V_ E || I_B || I_E
+|-
+| || || || ||
+|-
+| || || || ||
+|-
+| || || || ||
+|-
+| || || || ||
+|-
+| || || || ||
+|-
+| || || || ||
+|}
+.) Repeat the previous measurements for <math>I_B \approx 5 \mbox{ and } 10 \mu</math> A.  Remember to keep <math>I_CV_{CE} < P_{max}</math> so the transistor doesn't burn out
+.) Graph <math>I_C</math> -vs- <math>V_{CE}</math> for each value of <math>I_B</math> and <math>V_{CC}</math> above. (40 pnts)
+.) Overlay points from the transistor's data sheet on the graph in part 5.).(10 pnts)
 =Questions=
-#Why does a flat load line produce a high voltage gain and a steep load line a high current gain? (10 pnts)
-#What would be a good operating point an an <math>npn</math> common emitter amplifier used to amplify negative pulses?(10 pnts)
+#Compare your measured value of <math>h_{FE}</math> or <math>\beta</math> for the transistor to the spec sheet? (10 pnts)
-#What will the values of <math>V_C</math>, <math>V_E</math> , and <math>I_C</math> be if the transistor burns out resulting in infinite resistance.  Check with measurement.(10 pnts)
+#What is <math>\alpha</math> for the transistor?(10 pnts)
-#What will the values of <math>V_C</math>, <math>V_E</math> , and <math>I_C</math> be if the transistor burns out resulting in near ZERO resistance (ie short).  Check with measurement.(10 pnts)
+#The base must always be more _________(________) than the emitter for a npn (pnp)transistor to conduct I_C.(10 pnts)
-#Predict the change in the value of <math>R_{in}</math> if <math>I_D</math> is increased from 10 <math>I_B</math> to 50 <math>I_B</math>(10 pnts)
+#For a transistor to conduct I_C the base-emitter  junction must be ___________ biased.(10 pnts)
-#Sketch the AC equivalent circuit of the common emitter amplifier.(10 pnts)
+#For a transistor to conduct I_C the collector-base  junction must be ___________ biased.(10 pnts)
 [[Forest_Electronic_Instrumentation_and_Measurement]]

Difference between revisions of "TF EIMLab13 Writeup"

Revision as of 22:42, 8 March 2011

Transistor circuit

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