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Free Electronics Plans on the Internet

By Gary Novak

Pin Connections

All unused CMOS inputs must be connected to one of the rails to prevent oscillations. They must be the same voltage as the plus or ground pins for the chip.

High speed CMOS (such as 74HC14) will substitute for regular, but the voltage range reduces to 2-6 volts, and it requires more input current limiting the size of input or feedback resistors. The usual voltage range for CMOS is 3-15V. Generally, 74Cxx will drive a heavier load than 40xx.

Op amp balance pins (1, 5 or 8) are not used in these circuits and can be left unconnected.

Op amps - LF351, LF441 or TL061: (TL types are not as good of quality.)
1 pin - balance, not connected
2 pin - inverting input
3 pin - noninverting input
4 pin - minus V
5 pin - balance, not connected
6 pin - output
7 pin - plus V
8 pin - not connected

Dual op amps - LF353, LF442:
1 pin - output for 2 and 3 pins
2 pin - inverting input
3 pin - noninverting input
4 pin - minus V
5 pin - noninverting input
6 pin - inverting input
7 pin - output for 5 and 6 pins
8 pin - plus V

Usual small signal transistors (PN2222A) and darlington MPSA13:
left = emitter
center = base
right = collector
when looking at flat surface in front.

There are six Schmidt triggers on a single chip, 74C14 or 40106:
1 pin in - 2 pin out
3 pin in - 4 pin out
5 pin in - 6 pin out
7 pin - ground
9 pin in - 8 pin out
11 pin in - 10 pin out
13 pin in - 12 pin out
14 pin - plus voltage

4020 - 14 Stage Binary Counter (divide input frequency by quantity shown):
1 - output, q12, 4096
2 - output, q13, 8192
3 - output, q14, 16,384
4 - output, q6, 64
5 - output, q5, 32
6 - output, q7, 128
7 - output, q4, 16
8 - ground
9 - output, q1, 2
10 - clock in, negative edge
11 - high reset, low run
12 - output, q9, 512
13 - output, q8, 256
14 - output, q10, 1024
15 - output, q11, 2048
16 - plus V

4017 - Decade Counter:
1 pin - output position 5
2 pin - output position 1
3 pin - output position 0, resets to high
4 pin - output position 2
5 pin - output position 6
6 pin - output position 7
7 pin - output position 3
8 pin - ground
9 pin - output position 8
10 pin - output position 4
11 pin - output position 9
12 pin - carry out, ignore
13 pin - high stop, low run
14 pin - clock in, plus edge
15 pin - high reset, low run
16 pin - plus V

74C74 - Dual D Flip-Flop, low resets:
1 - (1) clear, low resets q low (q-bar high), high run
2 - (1) data in
3 - (1) clock in, plus edge
4 - (1) preset, low resets q-bar low (q high), high run
5 - (1) q out
6 - (1) q-bar out
7 - ground
8 - (2) q-bar out
9 - (2) q out
10 - (2) preset, low resets q-bar low (q high), high run
11 - (2) clock in, plus edge
12 - (2) data in
13 - (2) clear, low resets q low (q-bar high), high run
14 - plus V

4013 - Dual D Flip-Flop, high resets:
1 - (1) q out
2 - (1) q-bar out
3 - (1) clock in, plus edge
4 - (1) reset, high resets q-bar high (q low), low run
5 - (1) data in
6 - (1) set, high resets q high (q-bar low), low run
7 - ground
8 - (2) set, high resets q high (q-bar low), low run
9 - (2) data in
10 - (2) reset, high resets q-bar high (q low), low run
11 - (2) clock in, plus edge
12 - (2) q-bar out
13 - (2) q out
14 - plus V

4071 - OR Gate (same pinout as 4081 AND Gate):
1,2 in - 3 out
5,6 in - 4 out
8,9 in - 10 out
12,13 in - 11 out
7 - ground
14 - plus V

80C95 - Tri-State Hex Buffers:
1 - high cuts all, ORed with 15
2 - in A
3 - out A
4 - in B
5 - out B
6 - in C
7 - out C
8 - ground
9 - out D
10 - in D
11 - out E
12 - in E
13 - out F
14 - in F
15 - high cuts all, ORed with 1
16 - positive voltage
 

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