Circuits
1. Constant Current Source
2. Constant Current Sink
3. MOSFET Power Switch
Screencast: 3:17
Lab Supplies• Resistors
1 7.5 Ohm, 6.5 Watt (From Lab Monitors)
1 150 Ohm
1 499 Ohm
2 20.0 KOhm
1 100 Kohm
• Transistors
1 2N5088G
1 2N5087G
1 2N7000TA
1 NTP2955G
Screencast: 3:33
Lab Supplies• Breadboard
• Digital-Multi-meter
• Power Supply
• Banana to Banana, black (1)
• Banana to Banana, red (1)
• Banana to Mini-grabber, black (2)
• Banana to Mini-grabber, red (2)
• Banana to Mini-grabber, green (1)
Screencast: 4:00
Test Set-up 1
• Power Supply• Program the +25V supply for +12 Volts• Use the following banana to mini-grabber color codes
• Red: +12V• Black: Ground
• Digital Multimeter• Use banana to mini-grabbers ( Red, Black)
Screencast: 4:21
Constant Current Source
ConstantEuropean
Symbol
Controlled Current Source
Screencast: 4:33
Calculations and Measurements• Circuit 1 and 2 (BJTs)
• Using the base voltage and the emitter resistor, calculate the emitter current. Assume that V
BE is 0.65 V.
•Measure collector currents
CircuitCalculatedValue (mA)
Measured Value (mA)
NPN Current Sink
Current Sink Results
CircuitCalculatedValue (mA)
Measured Value (mA)
PNP Current Source
Current Source Results
Screencast: 8:48
Test Set-up 2
• Power Supply• Connect the two black commons together using the black banana to banana cable• Program the +6V supply for +5 Volts.• Program the +25V supply for +12 Volts• Use the following banana to mini-grabber color codes
• Red: +12V• Black: Ground• Green: +5V
• Digital Multimeter• Use banana to mini-grabbers ( Red, Black)
Screencast: 8:58
Measurements• Circuits 1 & 2 ( Current source and sink)
• Measure collector currents
• Circuit 3• Measure source to drain current P channel fully on (N channel G at 5 V)• Decrease N channel gate voltage and document the minimum on voltage for the circuit ( S-to-D current should be greater than 90% of full on value)
Circuit Value
P Channel S-to-D CurrentN Channel On Voltage
MOSFET Power Switch
Screencast: 11:56
Lab 7 Results
Circuit Value
P Channel S-to-D Current
N Channel On Voltage
MOSFET Power Switch
CircuitModified Resistor
Value (Top R in Base Voltage
Divider)
CalculatedVB
CalculatedVE
CalculatedValue (mA)
Measured Value (mA)
PNP Current Source
CircuitModified Resistor
Value (Bottom R in Base Voltage Divider)
CalculatedVB
CalculatedVE
CalculatedValue (mA)
Measured Value (mA)
NPN Current Source
Current Source Results (2nd Circuit in Demo, 1st in Screencast)
Current Sink Results (1st Circuit in Demo, 2nd in Screencast)
NTP2955 GDS
2N7000 SGD
2N5087 EBC
2N5088 EBC
ASSUME β = 500
Screencast: 12:40