gres
Full Member level 4
What is the difference between current source and current sink?
At first side you may find it the same, but it is not. Those terms are connected with current direction. When you have a sink, current will flow into output of device. Opposite with current source, in this case, current goes out from the output. So for the example: most of integrated circuits can work with both sink and source. So if current flows from integrated circuit to the load, we have source, and circuit is on the high side. In opposite case, when current flows from the load to integrated circuit we have a sink and circuit is on low side.
As I said most of IC’s can work with both, but not all. For the example i/o ports of TRISTATE in AT89C52 microcontroller can work only with sink current.
Althought that there is no physical difference between both of currents.
Importand is also that most of IC has different maximum for sink current and source current, depends of internal circuitry.
There is a nice analogy that makes easy to understand source and sink. As you know, very often we can compare current to the water. Now imagine the wellhead = source. Water comes from underground and appear at the surface. Opposite effect is when upper-ground water goes down and disappear under the ground, then we have a sink. Similar with the current. When positive charges comes from invisible place to visible we have source ( underground water to the surface), of course negative charges will hide. With sink he have opposite situation.
Source and sink can be find not only In IC systems. Most complicated device that works with them is human brain.
At first side you may find it the same, but it is not. Those terms are connected with current direction. When you have a sink, current will flow into output of device. Opposite with current source, in this case, current goes out from the output. So for the example: most of integrated circuits can work with both sink and source. So if current flows from integrated circuit to the load, we have source, and circuit is on the high side. In opposite case, when current flows from the load to integrated circuit we have a sink and circuit is on low side.
As I said most of IC’s can work with both, but not all. For the example i/o ports of TRISTATE in AT89C52 microcontroller can work only with sink current.
Althought that there is no physical difference between both of currents.
Importand is also that most of IC has different maximum for sink current and source current, depends of internal circuitry.
There is a nice analogy that makes easy to understand source and sink. As you know, very often we can compare current to the water. Now imagine the wellhead = source. Water comes from underground and appear at the surface. Opposite effect is when upper-ground water goes down and disappear under the ground, then we have a sink. Similar with the current. When positive charges comes from invisible place to visible we have source ( underground water to the surface), of course negative charges will hide. With sink he have opposite situation.
Source and sink can be find not only In IC systems. Most complicated device that works with them is human brain.
