IC Pinout Reference (74xx Logic, 555, Op-Amps)
Top-view pin diagrams for the 74-series logic ICs, 555 timer and op-amps used in lab work, with the chips that have unusual power pins and their active-low pins called out.
Check before you insert it
The notch or dot on top of the IC marks the pin 1 end. With the notch at the top, pin 1 is top left; numbers run down the left side and back up the right. Most 14-pin chips put VCC on pin 14 and GND on pin 7, and 16-pin chips use 16 and 8, but there are exceptions such as the 7483, 7476, 7490 and 7493, so check this diagram or the datasheet before inserting. Tie every unused input to VCC or GND rather than leaving it floating.
Wiring example: an AND gate from one 7400
- Connect VCC (5 V) to pin 14 and GND to pin 7.
- First NAND: feed A and B into pins 1 and 2; pin 3 gives NOT (A AND B).
- Use the second NAND as an inverter: wire pin 3 to both pins 4 and 5.
- Pin 6 now gives A AND B. Tie the spare gates' inputs (pins 9, 10, 12, 13) to GND.
Power pins at a glance
| IC | Function | Type | Pins | VCC (V+) | GND (V−) |
|---|---|---|---|---|---|
| 7400 | Quad 2-input NAND | Gates | 14 | 14 | 7 |
| 7402 | Quad 2-input NOR | Gates | 14 | 14 | 7 |
| 7404 | Hex inverter | Gates | 14 | 14 | 7 |
| 7408 | Quad 2-input AND | Gates | 14 | 14 | 7 |
| 7410 | Triple 3-input NAND | Gates | 14 | 14 | 7 |
| 7420 | Dual 4-input NAND | Gates | 14 | 14 | 7 |
| 7432 | Quad 2-input OR | Gates | 14 | 14 | 7 |
| 7486 | Quad 2-input XOR | Gates | 14 | 14 | 7 |
| 7442 | BCD to decimal decoder | Decoders and encoders | 16 | 16 | 8 |
| 7447 | BCD to 7-segment decoder (common anode) | Decoders and encoders | 16 | 16 | 8 |
| 74138 | 3-to-8 line decoder | Decoders and encoders | 16 | 16 | 8 |
| 74147 | Decimal to BCD priority encoder | Decoders and encoders | 16 | 16 | 8 |
| 7483 | 4-bit binary full adder | Adders and multiplexers | 16 | 5 | 12 |
| 74151 | 8-to-1 multiplexer | Adders and multiplexers | 16 | 16 | 8 |
| 74153 | Dual 4-to-1 multiplexer | Adders and multiplexers | 16 | 16 | 8 |
| 74157 | Quad 2-to-1 multiplexer | Adders and multiplexers | 16 | 16 | 8 |
| 7474 | Dual D flip-flop (rising edge) | Flip-flops | 14 | 14 | 7 |
| 7476 | Dual JK flip-flop | Flip-flops | 16 | 5 | 13 |
| 74112 | Dual JK flip-flop (falling edge) | Flip-flops | 16 | 16 | 8 |
| 7490 | Decade counter (divide-by-2 and divide-by-5) | Counters and shift registers | 14 | 5 | 10 |
| 7493 | 4-bit binary counter (divide-by-2 and divide-by-8) | Counters and shift registers | 14 | 5 | 10 |
| 74193 | 4-bit up/down binary counter | Counters and shift registers | 16 | 16 | 8 |
| 74164 | 8-bit serial-in parallel-out shift register | Counters and shift registers | 14 | 14 | 7 |
| NE555 | 555 timer | Timer and op-amps | 8 | 8 | 1 |
| LM741 | General-purpose op-amp (single) | Timer and op-amps | 8 | 7 | 4 |
| LM358 | Dual op-amp (single-supply capable) | Timer and op-amps | 8 | 8 | 4 |
Bold marks chips whose power pins are not in the usual place. The table comes from the same data as the diagram above.
Frequently asked questions
How do I find pin 1 on an IC?
Look for the notch or dot on top. With the notch at the top, pin 1 is top left; numbers run down the left side and continue up the right side.
Do all 74-series chips put power on the corner pins?
No. Of the chips on this page, the 7483 (VCC pin 5, GND pin 12), the 7476 (VCC pin 5, GND pin 13), the 7490 (VCC pin 5, GND pin 10), the 7493 (VCC pin 5, GND pin 10) use other pins. Powering the usual corner pins on these chips does nothing, so always check the pinout first.