LM358 dual op-amp: pinout, single-supply limits, the LM358A and the LM324

The 358 is the dual and the 324 the quad. An A after the number (LM358A) marks a part sorted for lower offset and bias current. A B (LM358B, LM358BA) is TI's newer die with a wider supply range and more bandwidth, covered under substitutes. The last letter is the package: P or N is the through-hole DIP, D the SOIC. An LM358P is the plain dual in an 8-pin DIP; the SOIC version is marked just LM358.

The LM2904 sits in the same datasheet with the same pins. It is rated for −40 to 125 °C but only 26 V of supply, so check the number before you fit one on a 30 V rail.

TI allows 32 V across the LM358, or ±16 V on a split supply, and recommends 3 to 30 V for normal use. Either input may go from 0.3 V below V− to 32 V, which means an input can sit above V+ without harm, as long as it stays inside that range.

The output may be shorted to ground indefinitely, but only one amplifier at a time, at 25 °C or below, on 15 V or less. TI adds that a short from the output to V+ can overheat and destroy the part. Its ESD rating is ±500 V (human-body model), a quarter of the LM358B's ±2000 V, so handle it on a grounded mat.

The inputs work from V− up to 1.5 V below V+ at 25 °C, and up to 2 V below V+ over 0 to 70 °C. On 5 V that is 0 V to 3.5 V, or to 3 V when warm. The output swings from about 5 mV above ground (20 mV at most) up to 1.5 V below V+. So a 5 V LM358 has a working range of roughly 0 V to 3.5 V, not 0 V to 5 V.

It is slow: 0.7 MHz of gain-bandwidth and 0.3 V/µs of slew rate, both typical. Each amplifier draws about 350 µA, 600 µA at most. The input bias current flows out of the pins, up to 250 nA at 25 °C. The TL072 draws picoamps but cannot work near ground.

The output sources current well (20 mA minimum on 15 V) but sinks very little near ground: TI guarantees only 12 µA at 200 mV. If the load returns to V+ instead of to ground, the output will not pull it fully low.

• Sensor amplifiers on a 5 V or 12 V board: the voltage across a shunt resistor, an LM35 output, anything that starts at 0 V.
• Current sensing on the low side of a load, where the signal sits a few millivolts above ground.
• Battery chargers and supply monitors that need a reference and a comparator-like stage from the same rail.
• Slow active filters and buffers, below about 10 kHz.

It is a poor choice for audio above a few volts of swing, anything that must reach V+, and fast edges. For a comparator, use the LM393, a dual comparator, instead of an LM358 run open loop.

One half of an LM358 on a single 5 V supply, scaling a sensor that gives 0 to 300 mV so its full scale lands at 3.3 V, the top of a 3.3 V microcontroller's ADC.

Fit 100 nF from pin 8 to ground, close to the package. The non-inverting amplifier lesson derives the gain formula.

The LM358A uses the same pins and the same limits. TI sorts it for a 3 mV maximum offset against 7 mV, and a 100 nA maximum bias current against 250 nA. In the example above that takes the worst-case output error from 102 mV to 43 mV. Buy it for any DC-coupled stage with gain.

The LM324 puts four of the same amplifiers in a 14-pin DIP, with the same input range, output swing, offset and bias current in TI's tables. The trap is the supply: VCC+ is pin 4 and VCC− (ground) is pin 11. On the LM358, pin 4 is ground.

The whole LM324 draws 0.7 mA typical and 1.2 mA at most on 5 V, so about 175 µA per amplifier, against the 350 µA TI quotes for each half of an LM358.

• Keep every input at least 1.5 V below V+, or 2 V if the board gets warm. On 5 V that means nothing above 3 V.
• Plan the output to stop at V+ − 1.5 V. If you need a 0 to 5 V output, run the LM358 from a higher rail, such as 9 V or 12 V.
• An unused half still needs a defined state. Tie its non-inverting input to a voltage inside the input range and wire it as a follower.
• The bias current flows out of the inputs. A high-value resistor from an input to ground lifts that input: 250 nA through 1 MΩ is 0.25 V.
• Bypass pin 8 with 100 nF at the package. On the LM324 the bypass goes on pin 4.

The LM358A and LM358B drop into the same socket. The LM358B is the one to buy for new work: wider supply, more bandwidth and a lower offset. The LM2904 fits too, if the supply stays under 26 V.

1. Power the chip from 5 V and wire one half as a follower (output to pin 2). Put 1 V on pin 3: the output should read 1 V within the 7 mV offset.
2. Turn the input down to 0 V. The output should fall to a few millivolts, 20 mV at most. An output stuck high points to a damaged part or a floating input.
3. Rewire that half as the gain-of-11 stage above and raise the input past 320 mV. The output should stop rising near 3.5 V and stay there; that is the 1.5 V headroom, not a fault.
4. Measure the supply current with both halves wired as followers: about 0.7 mA, 1.2 mA at most. Much more points to oscillation or a damaged part.

Use the LM358 for slow signals that start at 0 V on a single supply, and size the gain so the output tops out at least 0.2 V below V+ − 1.5 V. Buy the LM358A or LM358B for any stage with gain, and pick a rail-to-rail op-amp when the output has to reach the supply.

The LM358P in DIP-8 and the LM324N in DIP-14 are stocked by most Indian component sellers, often without a maker named. Ask for TI or another named maker, and check one from each batch with the follower test above before it goes into a board. Our guide to buying electronic components in India compares ten online sellers and covers how to spot fakes.