Electrical – How to LM324 work in dual supply mode when it only has 2 pins for the supply

operational-amplifier

The LM324 quad opamp data here says that it can work in single as well as dual supply mode. However, it has pins for positive supply and another for ground on its sides. The pin for ground can also be used for negative supply as per the datasheet. However, if we shall only connect the +V and -V and no GND, how does the concept of -V arise in the operation of the op-amp?

Best Answer

The op-amp only knows about the voltage between its power pins. It doesn't know or care where you think "ground" (zero volts) is.

The circuit around the op-amp will determine where "ground" is relative to the op-amp's power supply pins.