Evaluation of 50 Ω driver circuits for digital signals based on oscilloscope measurements

In this article, various 50 Ω driver circuits for digital signals are compared and evaluated. These circuits can drive different logic families, even over longer cables, with fast rise and fall times of a few nanoseconds. A fully assembled test board and all measurement results are presented. The design files, source codes and measurement results can be freely downloaded from Mendeley Data. Does it make a difference if a solderless breadboard is used instead of a printed circuit board with solid ground plane? Apart from considerable noise on the breadboard's supply rail, the overall signal quality is better than one might expect. The test board is not only useful for evaluating driver circuits but can also be used directly as a simple pulse generator. Some of the driver circuits presented here show faster rise and fall times than many commercial function generators.