Operational Amplifiers are the workhorse of analog electronic designs. These humble devices are used from simple voltage followers to complicated inverter review film designs since the time immemorial. Here at CircuitDigest, we have already discussed a wide range of op-amp circuits and its applications. Today, we will be looking into another interesting concept associated with Op-Amps, called Virtual Ground and Virtual Short. So, let’s dive into it.
What is Virtual Ground and Virtual Short?
Before getting into the details, let us take a look at the figures given below. In Figure (a), the voltage at VA = VB, this is because there is a short circuit between VA and VB point. In figure (b), there is no connection (short circuit) between VA and VB. But still the voltage at VB = VA without connection with any other source means there should be a virtual connection in between VA and VB or due to some other virtual effect the VB is equal to VA. This is an effect commonly knows as “Virtual Short Circuit”.
Virtual Ground and Virtual Short
Likewise, in Figure (c), even if the VA is connected with a 5V source but due to some effects if the VA= VB = 0V (Gnd_Potential) means this effect will be called as “Virtual Ground”.
The above mentioned details may seem like magic or unrealistic. But, the basic Op-Amp operations follow the above two concepts, and understanding the reason behind this will help to understand full Op-Amp physics.