Opening Thoughts on Inductance

With the increasing prominence of high frequency integrated circuits, wiring properties such as inductance require special consideration. Many of these considerations are new to the digital world. Therefore, you are starting to see people looking at analog techniques for tools to deal with these frequencies. The popular adage, "The world has gone digital, analog is dead" is not so. Far from it.

Analog skills will always be needed. In fact, my recommendation to people studying electronics is "Forget the digital world, study analog and you will have a job for life." Sure, somebody has to know digital, but if you want to earn the real big bucks, study analog.

With analog, you might spend three months trying to design 10 transistors, as opposed to three months to design 12 million transistors in digital. It's too easy to design the 12 million transistors. Just a lot of copying. Let someone else do it. Go analog.

Let's get to work.

Basic Inductance

Whenever a current flows in a wire, a magnetic field is generated around the wire. Likewise, if we generate a magnetic field near a wire, current flows inside the wire. Current and magnetic field occur together. Always. ^[1]

The Right Hand Rule tells you the direction of the generated magnetic field. Grab the conductor with your right hand, your thumb extended in the direction of current flow. Your curled fingers mimic the lines of magnetism. This is also called the Hitchhiker Rule. If the...