Battery Charger Design (EE Tip #130)

Figure 1: This lead-acid battery charger uses Texas Instruments’s UC2906 IC.

It’s easy to design a good, inexpensive charger. There is no justification for selling cheap, inadequate contraptions. Many companies (e.g., Linear Technology, Maxim, Semtech, and Texas Instruments) supply inexpensive battery management ICs. With a few external parts, you can build … Continue reading


Active ESD Protection for Microcontrollers (EE Tip #129)

Figure 2—Typical ESD protection circuit, as found in an Atmel microcontroller

Microcontrollers need to be protected from of electrostatic discharge (ESD). You can use the circuit described in this post when you have an application requires a greater degree of ESD protection than what you get from an IC on its … Continue reading


Op-Amp Versus Comparator (EE Tip #128)


Practically every lecture course or textbook on electronics describes how to use an operational amplifier as a comparator. Here we look at the possibility in more detail, and see how it can often be a very poor idea. The idea … Continue reading


Build an Adequate Test Bench (EE Tip #127)

Test Board

It’s in our makeup as engineers that we want to test our newly received boards as soon as possible. We just can’t wait to connect them to a power supply and then use our test bench equipment (e.g., generators, oscilloscopes, … Continue reading


A Wire Is an Inductor (EE Tip #126)


I’m confident you know that you should keep wires and PCB tracks as short as possible. But I’m also sure that you will underestimate this problem fairly frequently. Remember that 1 cm of a 0.25-mm-wide PCB track is roughly equivalent … Continue reading