Introduction to the 7408 Integrated Circuit
The 7408 is a 14-pin TTL logic device containing four independent 2-input AND gates. Each output is HIGH only when both inputs are HIGH. The package pinout is shared across the TI SN7408, SN74LS08, and SN74S08 devices shown in the TI datasheet, but their output drive and switching values are not interchangeable. The numeric tables on this page are scoped to the commercial TI SN7408 unless a section explicitly says otherwise; confirm the exact suffix and manufacturer before substituting a part.
Features of 7408 IC
- Four independent 2-input positive-AND gates: Y = A · B
- Eight logic inputs and four logic outputs
- 14-pin pinout: VCC on pin 14 and GND on pin 7
- Recommended SN7408 supply: 4.75 V to 5.25 V
- SN7408 input thresholds: VIH at least 2.0 V; VIL at most 0.8 V
- SN7408 output-current limits: IOH = -0.8 mA and IOL = 16 mA
- Commercial SN74 operating range: 0 C to 70 C
- Package and marking depend on the exact orderable part number
IC 7408 pin diagram
The 7408 IC has 14 pins that provide a range of functions, such as enabling logic gates, outputs, and inputs. It is essential to understand the 7408 Pinout before attempting to use the device in any application. Having a good understanding of the pinout can help ensure the device is used correctly and safely.
Pin Descriptions of the 7408 IC
In the logic diagram of 7408, the “A” and “B” is input gate, “Y” is output gate, “GND” is ground, “VCC” is power supply.
7408 IC Electronic Specifications
Configuration:
| Package | SOIC or PDIP |
| Logic Family | TTL |
| Dual-In-Line (DIL) | 14 pin |
| Independent 2−Input AND Gates | 4 |
Supply and temperature limits (TI SN7408)
| Item | TI SN7408 Value | How to Use It |
|---|---|---|
| Absolute Maximum VCC | 7 V | Damage limit, not a normal operating target |
| Recommended VCC | 4.75 V to 5.25 V | Use this range for guaranteed SN7408 operation |
| Operating Free-Air Temperature | 0 °C to 70 °C | Commercial SN74 grade; SN54 military parts use a different range |
| Storage Temperature | −65 °C to 150 °C | Storage limit from the TI datasheet |
Recommended operating conditions (TI SN7408)
| Parameter | Symbol | Min | Nom | Max | Unit |
|---|---|---|---|---|---|
| Supply voltage | VCC | 4.75 | 5 | 5.25 | V |
| High-level input voltage | VIH | 2 | − | − | V |
| Low-level input voltage | VIL | − | − | 0.8 | V |
| High-level output current | IOH | − | − | −0.8 | mA |
| Low-level output current | IOL | − | − | 16 | mA |
| Operating free-air temperature | TA | 0 | − | 70 | °C |
Electrical characteristics (TI SN7408)
| Parameter | Symbol | Test Conditions | Min | Typ | Max | Unit |
|---|---|---|---|---|---|---|
| Input Clamp Voltage | VIK | VCC = MIN, II = −12mA | − | − | −1.5 | V |
| High Level Output Voltage | VOH | VCC = MIN, VIH = 2V, IOH = −0.8mA | 2.4 | 3.4 | − | V |
| Low Level Output Voltage | VOL | VCC = MIN, VIL = 0.8V, IOL = 16mA | − | 0.2 | 0.4 | V |
| Input Current | II | VCC = MAX, VI = 5.5V | − | − | 1 | mA |
| High Level Input Current | IIH | VCC = MAX, VI = 2.4V | − | − | 40 | µA |
| Low Level Input Current | IIL | VCC = MAX, VI = 0.4V | − | − | −1.6 | mA |
| Short-Circuit Output Current | IOS | VCC = MAX, Note 4 | −18 | − | −55 | mA |
| High Level Supply Current | ICCH | VCC = MAX, VI = 4.5V | − | 11 | 21 | mA |
| Low Level Supply Current | ICCL | VCC = MAX, VI = 0V | − | 20 | 33 | mA |
Switching characteristics (TI SN7408)
| Parameter | From | To | Test Conditions | Typ | Max | Unit |
|---|---|---|---|---|---|---|
| LOW-to-HIGH propagation delay (tPLH) | A or B | Y | VCC = 5 V, RL = 400 Ω, CL = 15 pF, TA = 25 °C | 17.5 | 27 | ns |
| HIGH-to-LOW propagation delay (tPHL) | A or B | Y | VCC = 5 V, RL = 400 Ω, CL = 15 pF, TA = 25 °C | 12 | 19 | ns |
Applications of the 7408 IC
– Digital Logic Gates
– Binary Counters
– Multiplexers
– Flip-flops
– Bus Driver/Receiver
– Address Decoders
– Data Latches
– Logic gate circuits
– Decoders
– Shift registers
– Counters
– Arithmetic circuits
Verify the exact 7408 variant before applying data-sheet values
The pinout is shared by the cited TI SN7408, SN74LS08 and SN74S08 variants, but the tables on this page apply only to the commercial SN7408.
- Identify the logic family and manufacturer from the complete package marking.
- Before power-up, confirm pin 14 = VCC, pin 7 = GND, and all four A/B/Y groups.
- Keep every input at a defined logic level and calculate fan-out from the exact part’s IOH/IOL limits.
- Test each gate with 00, 01, 10, and 11; only 11 should produce a high output.
Official TI sources: TI SN74LS08; TI SDLS033.
