The Examples Tab demonstrates Current Mirrors, however what it fails to expand on is the efficiency of a current mirror; particularly with concern for device selection/technology. Replicating the current is obviously important. In addition to the replication, the current drop associated with CMOS vs TTL is not clearly explained.
What we can see here is single BJT & FET current mirrors. Additionally we have Darlington Pairs and a P-Channel mirror. What is worth taking note is how much more effective the BJTs are at replicating current as opposed to the FETs. This makes sense because BJTs are current based devices, unlike the FETs which are voltage based devices.
The take-home here is to be able to clearly see how each assortment of devices replicates the current and the accuracy with which they replicate. Adjust the voltage sources to see how the CMOS designs fair against the TTL devices. Since BJTs are based around current, one should note that they are able to replicate currents much better than their brother FETs.
While this is not a hugely important circuit or demonstration, the Examples Tab does not add any clarity to the device of choice for this particular purpose. This circuit aims to fill that gap and add a better visual representation for current mirroring and the chosen devices to fulfill that role.
If anyone has any additional information or clarification on current mirroring please be sure to share with the community. =)
