A friend recently sent me an email noting that the classic 2N3904 bipolar transistor was now 60 years old. Since its “birth” was before I got involved with basic electronics, that callout was ...

How do we find the values of junction capacitances? Well, we re fortunate if manufacturers data is available. For instance, for the 2N3904 transistor, capacitance data is available for reverse bias ...

A Planet Analog article, “2N3904: Why use a 60-year-old transistor?” by Bill Schweber, inspired some interest in this old transistor and how it’s commonly used, and if any uncommon uses might exist.

Manufacturers sometimes (but not always) put switching time test results on their datasheets. Shown below are test circuits and test results for the 2N3904 NPN transistor. [6] From these test results ...