LM324 is a 14pin IC consisting of four independent operational amplifiers (op-amps) compensated in a single package. Op-amps are high gain electronic voltage amplifier with differential input and, usually, a single-ended output. The output voltage is many times higher than the voltage difference between input terminals of an op-amp.
These op-amps are operated by a single power supply LM324 and need for a dual supply is eliminated. They can be used as amplifiers, comparators, oscillators, rectifiers etc. The conventional op-amp applications can be more easily implemented with LM324.
Pin Description:Pin No Function Name 1 Output of 1st comparator Output 1 2 Inverting input of 1st comparator Input 1- 3 Non-inverting input of 1st comparator Input 1 4 Supply voltage; 5V (up to 32V) Vcc 5 Non-inverting input of 2nd comparator Input 2 6 Inverting input of 2nd comparator Input 2- 7 Output of 2nd comparator Output 2 8 Output of 3rd comparator Output 3 9 Inverting input of 3rd comparator Input 3- 10 Non-inverting input of 3rd comparator Input 3 11 Ground (0V) Ground 12 Non-inverting input of 4th comparator Input 4 13 Inverting input of 4th comparator Input 4- 14 Output of 4th comparator Output 4
THE OP-AMP AS A COMPARATOR
The OP-AMP can compare two signals (voltages). This is called a COMPARATOR or DIFFERENTIAL AMPLIFIER (amplifies the difference between two signals). There are two arrangements – connection to a single rail or dual rails. The animations below show the output for each configuration: