App note: Useful analog circuits for digital systems

Here is an oldie, but a goodie. The late analog guru Jim Williams describes lots of analog circuits that were used in digital systems. Most of these are now integrated into digital ICs, some are still in use today.

The pristine, regimented symmetry of  digital circuit boards is occasionally interrupted by an irregular huddle of linear components. These aberrants are tolerated because they perform a variety of ancillary tasks necessary to keep the digital system running. While I certainly wouldn’t wish lifetime employment on a digital circuit board to anyone*, the reality is that the need exists.
*I suppose it’s not all that bad. Some of my best friends are digital circuits. If I had a daughter, I’d even consider letting her go out with one.