Lab 17 RS

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The JFET (Junction Field Effect Transistor n-channel)

File:JFET MPF102 DataSheet.pdf

1). Complete the table below for the JFET.

Characteristic	Symbol	Min	Max	Unit
Zero-Gate-Voltage Drain Current	[math]\displaystyle{ I_{DSS} }[/math]	2.0	20	mAdc
Gate-Source Cutoff Voltage	[math]\displaystyle{ V_{GS(off)} }[/math]	-	-8.0	Vdc
	[math]\displaystyle{ P_{max} }[/math]
	[math]\displaystyle{ R_G }[/math]	3.3 M[math]\displaystyle{ \Omega }[/math]
	[math]\displaystyle{ R_D }[/math]	1.0 M[math]\displaystyle{ \Omega }[/math]
	[math]\displaystyle{ y_{fs} }[/math]
	[math]\displaystyle{ y_{is} }[/math]
	[math]\displaystyle{ y_{os} }[/math]

2.) Construct the JFET circuit below.

3.) Plot measurements of [math]\displaystyle{ I_D }[/math] -vs- [math]\displaystyle{ V_{DS} }[/math] by varying [math]\displaystyle{ V_{dd} }[/math] for [math]\displaystyle{ \left | V_{GS}\right | }[/math] = 0, 0.5, 1.0, 1.5 V. (40 pnts)

I have used the following resistors:

[math]\displaystyle{ R_G = (3.34 \pm 0.02)\ M\Omega }[/math]
[math]\displaystyle{ R_D = (0.968 \pm 0.002)\ k\Omega }[/math]

Below is the table with my measurements of voltages [math]\displaystyle{ V_{DS} }[/math] and [math]\displaystyle{ V_{R_D} }[/math] and calculation of the current [math]\displaystyle{ I_D }[/math]. Here I have used the meter to measure directly the voltage drop between the drain and source [math]\displaystyle{ V_{DS} }[/math] and to measure the voltage drop on resistor [math]\displaystyle{ R_D }[/math].

So my calculated current becomes:

[math]\displaystyle{ I_D = \frac{V_{R_D}}{R_D} }[/math].

And below I have plotted four curves [math]\displaystyle{ I_D }[/math] as function of [math]\displaystyle{ V_{DS} }[/math] for four different values of [math]\displaystyle{ V_{GS} }[/math]

4.) Plot [math]\displaystyle{ I_D }[/math] -vs- [math]\displaystyle{ V_{GS} }[/math] (30 pnts)

For every measured [math]\displaystyle{ V_{GS} }[/math] values I have picked up the current [math]\displaystyle{ I_D }[/math] values in the middle of saturation region of each line as follow:

Question

1. Does [math]\displaystyle{ y_{fs} }[/math] depend on[math]\displaystyle{ I_D }[/math]? (10 pnts)

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