IQAN University: Circuit Protection for High Side Outputs

When working with high side outputs in IQAN Design, it’s important to include an extra level of security to your circuit. Particularly with on/off functions, Parker Hannifin recommends integrating a flyback diode to protect the semiconductor output from being blown out. Looking at a typical closed high side output, the current goes from the source through the load (a coil, in this case) to ground. With an inductive load like a coil, energy can be stored. When the output is being turned off, energy stored in the coil will release back toward the output with a high enough voltage in that fraction of time to break or severely damage the semiconductor.

Adding a flyback diode does not affect the circuit while the output is on, but when it is being switched off, the diode provides another, lower resistance path for the current to dissipate. Check out the video below to take a closer look at how these diodes are integrated into circuits, and check out the full IQAN University playlist for more on-demand targeted skills training.