1Pin 1 notch
2LM358N dual op-amp
3Pin 1 dot
4Epoxy body (DIP-8) · 9.6 × 6.35 mm
5Pins (2.54 mm pitch)

Black DIP-8 body, notch and dot, “LM358N” text on top
DIP-8: body ≈ 9.8 × 6.4 mm, pin pitch 2.54 mm

Integrated circuits

Op-amp (LM358)

In simple terms

What is this?

A small magnifying glass that compares two inputs and enlarges the difference; it makes a tiny difference obvious.

What is it for?

Amplifies a small sensor signal, or compares two voltages and answers yes or no.

Where do you see it?

In boards with sensors and in audio amplifiers.

How do you spot it?

A small black IC with eight legs in two rows; the type code is printed on top.

Caution:

Count the pins from the notched end; its output does not reach the full supply voltage.

Technical definition

A common IC containing two operational amplifiers (op-amps) in one package, able to run from a single supply. The input range includes ground (0 V), which makes it handy for sensor signals. Its output cannot quite reach the supply voltage.

Power supply3–32 V

Contents2 op-amp

GBW≈1 MHz

Schematic symbol IEC and ANSI differ

IEC 60617: the drawing style used in Türkiye and Europe.

Pins 8

1OUT ATop left when the notch is up; op-amp A outputOUT

2IN− AA’s inverting inputIN−

3IN+ AA’s non-inverting inputIN+

4GNDGround on a single supply (V− on a dual supply)GND

5IN+ BB’s non-inverting inputIN+

6IN− BB’s inverting inputIN−

7OUT BB op-amp outputOUT

8VCCPower supply, 3–32 VVCC

Features typical

Power supply: 3–32 V (single) · ±1.5–±16 V (dual)
Gain-bandwidth: ≈1 MHz (0.7 MHz in some datasheets)
Input range: From 0 V to VCC − 1.5 V
Output swing: Close to 0 V, at most ≈ VCC − 1.5 V
Input offset: ≤ 7 mV
Slew rate: ≈0.3 V/µs
Power supply current: ≈0.5–1 mA
Example part: LM358N (DIP-8)

Common mistakes

Assuming it is rail-to-railOn a 5 V supply the output doesn't exceed ≈3.5 V. If you need the full 5 V, choose a rail-to-rail op-amp.

Forgetting the unused op-ampDo not leave the unused second op-amp floating; make it a voltage follower and tie its input to a fixed voltage (e.g. GND).

Expecting a fast signalA slow op-amp; at high gain it attenuates signals above a few kHz.

Test with a multimeter

Test whether this part is good with the multimeter on the measurement screen.

Take a measurement

Where it is used

Comparator for an LDR or NTC thresholdSensor signal amplifierVoltage follower (buffer)Active filter