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What do you mean by virtual ground?
In electronics, a virtual ground (or virtual earth) is a node of a circuit that is maintained at a steady reference potential, without being connected directly to the reference potential.
What is the meaning of virtual ground in op amp?
In opamps the term virtual ground means that the voltage at that particular node is almost equal to ground voltage (0V). It is not physically connected to ground. This concept is very useful in analysis of opamp circuits and it will make a lot of calculations very simple.
What does sink current mean in a circuit?
Sink current is the ability of the port to receive current. When you have a simple circuit where a digital input connects to a digital output, you need three components; a voltage source, a ground, and a load. A sourcing digital I/O provides the voltage, a sinking I/O the ground, and the digital input provides the load.
When does a current sink, it is sourcing?
Simply speaking, if the current exits a device terminal (output or input), it is sourcing; if it enters the device terminal, it is sinking. It seems strange but some inputs can source current (e.g., TTL inputs).
How does a sourcing digital input and output work?
A sourcing digital I/O provides the voltage, a sinking I/O the ground, and the digital input provides the load. This means that the input and output works in pairs: Figure 1 shows a sinking digital output that is connected to a sourcing digital input. In this circuit, the load is pulled to ground because of the sinking digital input provided.
When to use sinking current in a microcontroller?
Sinking current can be very useful when the load requires a higher operating voltage than the microcontroller’s internal operating voltage. Special attention needs to paid to ensure that the current is limited so as not to exceed the maximum current handling capacity of the GPIO pin.