Make Electronics

Chips, Ahoy! 193

Experiment 19: Learning Logic

FundAmentAls

Common part numbers

Each 14-pin chip can contain four 2-input gates, three
3-input gates, two 4-input gates, one 8-input gate, or six
single-input inverters, as shown in the following table.

2 input 3 input 4 input 8 input

AND 7408 7411 7421

NAND 7400 7410 7420 7430

OR 7432 744078*

NOR 7402 7427 744078*

XOR 7486

XNOR 747266

Inverter (1 input) 7404

*The 744078 has an OR output and a NOR output on the same chip.

Figures 4-66 through 4-74

show the internal connec-

tions of the logic chips that

you are most likely to use.

Note that the 7402 NOR

gate has its logical inputs

and outputs arranged dif-

ferently from all the other

chips.

Figure 4-66. Figures 4-66

through 4-74 show pinouts

for some of the most widely

used logic chips. Note that the

inputs of the 7402 are reversed

compared with the other chips.

7402

Quad

2-Input

NOR gate

3

4

1

2

14

13

12

11

6

7

10

9

8

5

7404 +e[

InYeUteU

3

4

1

2

14

13

12

11

6

7

10

9

8

5

Figure 4-67

7410

Triple

3-Input

NAND gate

3

4

1

2

14

13

12

11

6

7

10

9

8

5

Figure 4-68

7411

Triple

3-Input

AND gate

3

4

1

2

14

13

12

11

6

7

10

9

8

5

Figure 4-69

7420

Dual

4-Input

NAND gate

3

4

1

2

14

13

12

11

6

7

10

9

8

5

Figure 4-70

7421

Dual

4-Input

AND gate

3

4

1

2

14

13

12

11

6

7

10

9

8

5

Figure 4-71

7427

Triple

3-Input

NOR gate

14

7

1

2 13

3

4

12

11

6

10

9

8

5

Figure 4-72

7432

Quad

2-Input

OR gate

3

4

1

2

14

13

12

11

6

7

10

9

8

5

Figure 4-73

7486

Quad

2-Input

XOR gate

3

4

1

2

14

13

12

11

6

7

10

9

8

5

Figure 4-74