What is low-side drive and high-side driver?

・In Japanese
＜Premise knowledge＞
・transistor

■low-side driver and high-side driver

A type that has a drive switch (transistor) on the upstream side of a load such as a motor is called high-side drive, and a type that has a drive switch on the downstream side is called low-side drive.



Note that the types of transistors used as switches are different. A PNP transistor is used for high-side drive, and an NPN transistor is used for low-side drive.

Which is better, low side drive or high side drive?
Either low-side or high-side drive can be used to drive a device, but how to use it depends on whether you want to protect the parts or the transistor circuit when a ground short fault occurs. As shown below, if a ground short occurs during low-side drive, the parts will continue to rotate. On the other hand, if a ground short occurs during high-side drive, a large current will flow through the transistor.

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