Operational Amplifier Op Amp DIP LM393

AED 5.25



LM393 has two internal operational amplifiers.. These are internally adjusted for frequency. Split power supplies allow the LM-393 to function effectively as well. The common mode input voltage of the LM393 includes the ground. Wide voltage supply ranges, a negligibly tiny current drain, low input offset and bias currents, and output voltage suitable with transistor-transistor logic are all present. Industrial applications, battery-powered systems, analog to digital converters, limit comparators, time delay generators, etc. are only a few examples of its applications.

Package Includes:

  • 1 x Operational Amplifier Op Amp DIP LM393


  • Two separate voltage comparator operational amplifiers in a single package.
  • Can be operated from single and dual power supplies.
  • Operated from wide supply voltage from 2V to 36V.
  • Requires low operating current of around 400uA only.
  • Requires very low input bias and offset current.
  • It output can be easily used to drive most logic systems.
  • High Accuracy
  • Reliable to use in commercial devices.
  • Low cost
  • Suitable for portable/battery-operated devices.


There are two operating amplifiers inside the LM-393. These are internally adjusted for frequency. Split power supplies allow the LM-393 to function effectively as well. The size of the power supply has no bearing on the current drain supply. The ground is incorporated in the common mode input voltage of the LM 393, which is one of its most astounding features. Additional properties of the LM 393 include wide voltage supply ranges, a very low current drain supply, low input offset current, low input bias current, and output voltage compatibility with transistor-transistor logic. In real life, there are numerous locations where LM 393 can be applied. Industrial applications, battery-powered systems, analog to digital converters, limit comparators, time delay generators, etc. are only a few examples of its applications.

Principle of Work:

Op amps are essentially multistage amplifiers with extremely intricate connections between their various amplifier stages. Numerous transistors, FETs, and resistors make up its internal circuit. All of this takes up very little room. Therefore, it is available in the form of an Integrated Circuit (IC) and is packaged in a compact box. An amplifier that can be set up to carry out different operations, such as amplification, subtraction, differentiation, addition, and integration, is referred to as an "op amp." Two input terminals and one output terminal compensate for an op-amp. There are two voltage supply terminals on the op-amp as well. The differential input is made up of two input terminals. We refer to the terminal of the operational amplifier denoted by a negative (-) sign as the inverting terminal and the terminal denoted by a positive (+) sign as the non-inverting terminal. The amplified output signal is 180 degrees out of phase with respect to the applied input signal if an input signal is supplied to the inverting terminal (-). The output signal will be in phase, or without phase shift with respect to the input signal, if we apply an input signal to the non-inverting terminal (+).

There are two separate comparators in the LM393. Each of the comparators has a single output and two inputs (IN- and IN+) (OUT). The comparator compares something, namely the voltages at IN and IN+, as its name suggests. There is a transistor at OUT whose state is dependent on the voltage ratio:

When IN- voltage exceeds IN+, OUT is closed.
OUT is open because IN- voltage is smaller than IN+ (Open Collector)
Polarity shifts from 0 to VPU when a pull-up resistor with voltage VPU is connected to OUT. You now possess your digital signal:

VOUT equals VPU and IN- is less than IN+.
VOUT = 0 V and IN- is larger than IN+

Pinout of the Module:

Pin Number

Pin Name




The output of Op-Amp 1



Inverting Input of Op-Amp 1



Non-Inverting Input of Op-Amp 1



Ground or Negative Supply Voltage



Non-Inverting Input of Op-Amp 2



Inverting Input of Op-Amp 2



Output of Op-Amp 2



Positive Supply Voltage


  • Alarm clocks, traffic lights, light intensity meters, and burglar alarm circuits are a few further uses.


The LM393's operation is demonstrated in the circuit below. The voltages VREF, VIN, and VOUT are measured for us by an Arduino.

The voltage divider R1/R2 outputs 2.5 volts (ideally). This voltage serves as our reference.
Potentiometer-supplied variable signal voltage VIN is provided.
LED1 begins to glow when OUT is open. The LM393 functions as a current sink, therefore pay attention to the polarity.
VIN is measured at point A1, VRef at point A0, and VOUT at point A2.

When you adjust the voltage with the potentiometer, the output on the serial monitor will change:


 No Library is needed for this IC to function


const int refPin = A0;
const int vInPin = A1;
const int vOutPin = A2;
float vRef, vIn, vOut;
void setup() {
void loop() {
 vRef = analogRead(refPin)*5.0/1023;
 vIn = analogRead(vInPin)*5.0/1023;
 vOut = analogRead(vOutPin)*5.0/1023;
 Serial.print("VRef = ");
 Serial.print(" | VIn = ");
 Serial.print(" | VOut = ");

Technical Details:

  • Dual Comparator in a single package
  • Wide power supply Range 
  • Singe supply – 2V to 36V
  • Dual supply – ±1V to ±18V
  • Drain Current of only 0.4mA
  • Input Offset Voltage is ±5mV maximum
  • Power Dissipation: 660mW
  • Can Drive most of the TTL and MOS loads
  • Output can be Isolated from System's Ground
  • Low Offset Voltage and current



Although the input specs appear to be comparable, it is obvious that the LM358 Op-Amp has a lower bias current and offset voltage since these factors are important when used as an amplifier, which is where it is intended to be employed. In contrast, because a comparator is made to be used just to compare voltages rather than amplify them, the LM393 performs slightly worse in terms of input bias and offset performance. The substantial signal voltage gain also reflects this. To make the output transition as quick as feasible, the comparator's gain is substantially higher than the op-amp's, which has a much smaller gain. Since the comparator is not compensated, its bandwidth is also not stated. 




Supply Voltage

32V, +/-16V

36V, +/-18V

Differential Input Voltage



Input Offset Voltage

3mV max.

5mV max.

Input Bias Current

100nA max.

250nA max.

Input Common Mode Range

0V to V+ - 2V

0V to V+ - 1.5V

Large Signal Voltage Gain

100V/mV typ.

200V/mV typ.



Not specified