Pinout diagram
Summary specifications
Full pin reference
| Pin | Name | Group | Direction | Levels | Description |
|---|---|---|---|---|---|
| 1 | OUT A | Analog | Output | Analogue | Amplifier A output. The two halves are MIRRORED: A runs output (1), inverting input (2), non-inverting input (3). B runs them in the opposite order: non-inverting (5), inverting (6), output (7). The inputs swap round between the two halves — the classic breadboard error. |
| 2 | -IN A | Analog | Input | Analogue | Amplifier A inverting input. |
| 3 | +IN A | Analog | Input | Analogue | Amplifier A non-inverting input. |
| 4 | GND | Ground | Power | 0 V (or V-) | Ground for single-supply use, or the NEGATIVE supply for split-rail use. TI labels this pin "GND / V-". Note both roles. |
| 5 | +IN B | Analog | Input | Analogue | Amplifier B non-inverting input. Note the order reverses here: B starts with non-inverting, then inverting, then output. |
| 6 | -IN B | Analog | Input | Analogue | Amplifier B inverting input. |
| 7 | OUT B | Analog | Output | Analogue | Amplifier B output. |
| 8 | V+ | Power | Power | +3 V to +32 V | Positive supply. Wide supply range: about 3 V to 32 V single, or +/-1.5 V to +/-16 V split. The output cannot swing all the way to V+ — it stops roughly 1.5 V short. It can pull close to ground. |
Common uses and repair diagnostics
The LM358 is a dual operational amplifier in an 8-pin DIP. The headline — and the classic breadboard error with this part and every other dual op-amp in the same 8-pin standard — is that the two halves are MIRRORED. Amplifier A runs output, inverting input, non-inverting input on pins 1, 2, 3. Amplifier B runs them in the opposite order: non-inverting input, inverting input, output on pins 5, 6, 7. So the inputs swap round between the two halves. The headline feature is single-supply operation: the inputs work right down to the negative rail, so you can run it from one +5 V supply with no negative rail at all. That is what distinguishes it from a 741 and why it appears everywhere in 5 V-only retro hardware.
The LM358 is a dual operational amplifier in an 8-pin DIP. Used in audio buffering and mixing on retro sound mods, composite and S-video output stages, joystick and paddle conditioning, power-supply monitoring, and as the general-purpose glue analogue part on repair benches.
The two halves are MIRRORED. Amplifier A runs output, inverting input, non-inverting input on pins 1, 2, 3. Amplifier B runs them in the opposite order: non-inverting input, inverting input, output on pins 5, 6, 7. So the inputs swap round between the two halves. That is the classic breadboard error with this part and with every other dual op-amp in the same 8-pin standard — lead with it.
Pin 4 is GND for single-supply use, or the NEGATIVE supply for split-rail use; pin 8 is V+. TI labels pin 4 "GND / V-". Note both roles. The headline feature is single-supply operation: the inputs work right down to the negative rail, so you can run it from one +5 V supply with no negative rail at all. That is what distinguishes it from a 741 and why it appears everywhere in 5 V-only retro hardware.
The catch, and the thing most often mistaken for a faulty chip: the output cannot swing all the way to V+ — it stops roughly 1.5 V short. It can pull close to ground, but not to the positive rail. Design around it or use a rail-to-rail part. Wide supply range (about 3 V to 32 V single, or +/-1.5 V to +/-16 V split), internally frequency compensated, roughly 1 MHz gain-bandwidth. Slow by modern standards, which is fine for audio and sensor work and is why it is still everywhere.
The LM2904 is the automotive-grade equivalent; the LM158 and LM258 are the wider-temperature versions. The LM324 is the same architecture with four amplifiers in a 14-pin package. All are the same pinout convention per channel.
- Check V+ on pin 8 and ground on pin 4 first.
- Exploit the golden rule: in a working circuit with negative feedback, the two input pins of an amplifier should sit at very nearly the same voltage.
- A persistent difference between pins 2 and 3 (or 5 and 6) means that half is not regulating: either the feedback path is broken or the amplifier is dead.
- An output stuck hard at either rail with the inputs clearly not equal confirms a dead amplifier.
- Remember the output cannot reach V+ — it stops ~1.5 V short. This is normal, not a fault.