NOR Gate Experiment

Part 3. Procedure

1. Record here the exact device you are using.

2. Examine the data sheet for a '27 IC. Note the value of Vcc required and the maximum required supply current Icc

Vcc:

Icc:

3. Apply power to the '27 and verify proper operation of one of the 3 – input gates by measuring the output voltage level for each of the 8 input – signal combinations shown in Fig. 1. Use input – voltage levels of 0 = 0 V dc, 1 = +5 V dc, and use the measured output voltage levels complete the truth table below. 3-Input NOR Gate Diagram

A	B	C
0	0	0
+5	0	0
0	+5	0
+5	+5	0
0	0	+5
+5	0	+5
0	+5	+5
+5	+5	+5

4. Connect the 3 inputs on one of the gates together so it can be used as an inverter. Verify that the gates operates as an inverter by applying 0 V dc, and then +5 V dc to the input and recording outputs.

A	x
0 V dc
+5 V dc

5. Determine whether or not a 3 - input NOR gate will function as an inverter if 2 of the inputs are left unconnected and the third is used as a single output

6. Connect two of the NOR gates shown in Fig 2, and complete the truth table below to verify operation as an OR function. NOR Gate OR Function Diagram

A	B	Output
0	0
0	+5
+5	0
+5	+5

7. Connect three of the NOR gates shown in Fig 2 - 5, and complete the truth table below to verify operation as an OR function. More NOR Gates OR Function Diagram

A	B	x
0	0
0	+5
+5	0
+5	+5

Part 5. Questions

1. A '27 is to be used as a 2 - input NOR gate. What could you do with the extra input?

2. Explain the difference between a 54ALS27 and a 74ALS27.

3. Using the result from step 5, explain whether or not a '27 NOR gate will function as an inverter if the unused inputs are left connected.

4. Explain why NOR gate is considered to be a universal gate.

5. A certain logic network requires three inverters, two 3 - input AND gates, and one 2 - inputs OR gate. If the realization is to be accomplished using '27 NOR gates, what is the minimum number of '27s required? Draw the logic diagram for each type of realization.

6. Draw a logic diagram showing how to get the AND function x = ABC using '27 NOR gates and assuming all the functions and their complements are available.

NOR Gate Experiment

Student Information

Part 1. Objectives

Part 2. Equipment and parts required:

Part 3. Procedure

Part 5. Questions