A switching voltage regulator is one of my favorite circuits. In school, they were the first circuits I built where I understood how transistors worked. In fact, they were the first circuit I saw an inductor being useful! Switching regulators are incredibly efficient when designed properly. Of course, this detail about design is important. They are not as simple as a linear regulator, which is basically an IC and two caps.
To understand the basics of a switching regulator, I released AddOhms #18 this week. This is video tutorial dedicated the Switching Voltage Regulator. If video tutorials aren’t your thing, then keep reading for my written tutorial.
Linear regulators only need a small number of components, are simple to add to a board, but are not very efficient. Switching regulators can be made to be very efficient for a particular circuit, but can be difficult to design.
Back on AddOhms #17, we talked about how Linear Regulators work. In this tutorial, we are looking at switching regulators.
There are 4 core components needed in a switching voltage regulator.
Capacitors store energy in an electric field. When a voltage is applied, the capacitor charges up. When the voltage goes away, the capacitor discharges.
Inductors store energy in a magnetic field. When current flows through the inductor, a magnetic field is created. When the current stops, the magnetic field collapses generating current.
Switching voltage regulators work by making use of the energy storage properties of a capacitor and an inductor. To control the charge and discharge of these components, we use diodes and transistors.
As we discussed in AddOhms #8, diodes only allow current to flow in one direction. Later, we’ll see what that is important.
For more detail: Switching Voltage Regulator Tutorial