The 4-20 mA transmitters used in industrial current-control loops can be implemented as powered current sources, remote non-powered current sinks, or with several other I/O combinations. A useful ...

In order to test and characterize optical front end circuits, a controllable, high bandwidth, microamp-level current source is needed. However, most optocouplers on the market have large CTR variation ...

By leveraging the characteristics of transistor pairs and components, you can develop an add-on circuit that reduces the drift of a current source to near zero.

Contributing editor, Bob Pease, explains how to design several different circuits for limiting currents as high as 300 mA using an LM317, LM334N, IRF640 or IRF740.

O2Micro was issued 21 claims under US patent US 10,757,770 B2 on Aug 25, 2020, for the invention of light source driving circuits and a light source module. The module supports dual light sources ...