How LM324 Comparator Applied in a Circuit?

The LM324 comparator circuit consists of sensor voltage, reference voltage, Vcc, ground, and output pins. The LM324 operational amplifier IC can be worked as a comparator. On a single chip, this IC contains four independent operational amplifiers. This is a Low Power Quad Operational Amplifier with good stability and bandwidth that was designed to operate over a wide range of voltages from a single power supply.

The quad amplifier can run at supply voltages as low as 3.0 V and as high as 3.2 V, with quiescent currents roughly a quarter of the MC174's.

LM324 Circuit

The pin configuration of the IC LM324 is shown below, along with a description of each pin's function.

LM324 Comparator Pinout

• It can operate from 3 V to 30 V single power supply.

• It can operate from +/- 1.5 V to +/- 15 V for dual supply.

• It has bandwidth up to 1.3 MHz

• The large voltage gain of 100 dB

• 4 independent amplifiers

• Some of the variants are short circuit protected at the output.

• Rue differential input stages

• Very low current consumption: 375 uA.

• Low input bias current: 20 nA.

• Input offset voltage: typical: 2 mV, maximum: 7 mV.

• Input offset current typical: 2 nA, maximum: 20 nA.

• Input bias current typical: 20 nA, maximum: 100 nA.

• Large signal voltage gain ( Vcc = 15 v, RL, = 2 kohm, Vo = 1.4 V to 11.4 V): min: 50 V/mV, max: 100 V/mV.

• Slew rate (Vcc = 15 V, VI = 0.5 V to 3 V, RL = 2 Kohm, CL = 100pF, unity gain) typical: 0.4 V/uS

• Output current source [Vid = 1 V] (Vcc = 15 V, VO = 2V): minimum: 20 mA, Typical: 40 mA, Maximum: 70 mA.

• Output sink current [Vid = -1 V] (Vcc = 15 V, VO = 2V) Minimum: 10mA, Typical: 20 mA.

• High Level Output Voltage (Vcc = 30 V, RL = 2 K ohm) minimum: 26 V, Typical: 27 V.

• High Level Output Voltage (Vcc = 5 V, RL = 2 K ohm) minimum: 3 V.

• Low Level Output Voltage (RL = 10 k Ohm) Typical: 5 mV, Maximum: 20mV.

• Total harmonic distortion (f = 1 kHz, Av = 20 dB, RL = 2 kΩ, VO = 2 Vpp, CL = 100 pF, VCC = 30 V) typical: 0.015 %.

• Gain Bandwidth Product (VCC = 30 V, f = 100 kHz, Vin = 10 mV, RL = 2 kΩ, CL = 100 pF) Typical : 1.3 MHz.

• The LM324 is utilized as a comparator as well as an op-amp.

• The LM324 is an electronic voltage amplifier with a high gain.

• The LM324 comparator is generally used in the line following robot

• The applications of the conventional op-amp can easily be implemented by using the LM324

• The LM324 is applicable for oscillators, amplifiers, rectifiers, comparators, etc.

The voltage comparator is shown in the following schematic. The LM324 comparator and two 10K ohm resistors are required for this circuit. The two inputs, input A and input B come from the line sensor circuit's output, and the two resistors are utilized to establish the voltage reference so that the optimal digital output may be produced.

Comparator Circuit Using LM324

We can see that Node A and Node B are connected to the non-inverting inputs of the left and right comparators in the aforementioned circuit. The left comparator's output is connected to Microcontroller P1.0, while the right comparator's output is connected to Microcontroller P1.1. The non-inverting mode is used by both comparators.

The LM324 comparator circuit is made up of three LM324 comparators as well as other components such as resistors, capacitors, and ground. The following circuit demonstrates the operation of this comparator in easy steps.

Working of LM324 Comparator

When a voltage smaller than the op-inverting amp's voltage is applied to the non-inverting terminal, the output becomes zero, indicating that no current flows. We already know that "+ > – = 1" when "+ > – = 1". The '+' sign denotes a non-inverting terminal, while the '-' sign denotes an inverting terminal.

The output will be high if the non-inverting voltage is greater than the inverting voltage.

This LM324 output is internally coupled to resistance and has some internal structure, which distinguishes it from other comparators.

It is internally pulled up; therefore there is no need for a power supply resistor connection.