Terminology

Zap-o

I am really learning about electronics. I still have a questions that I have no where to get the answers from so I am leaning on you people to help me out.

What does it mean "High side" and "Low side" when on the topic of MOSFET drivers? I assume its the High side of an H-bridge but the H-bridge is not always the focus and yet its still mentioned.

Thanks in advance and - I am sure I will have more question about electronic slang

eod_punk

High side/Low side usually refers to where the FET is relative to the Load. If one end of the load is grounded, the switch is a HIGH-SIDE switch. If one end of the load is tied to Vcc, then the switch in series with it is a LOW_SIDE switch.

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sylvie369

While you're asking, how about someone also explain what difference it makes which of the two you use?

That was a nice, clear explanation, EOD.

kwinn

In most cases it does not matter to the load whether you use a high side or low side switch. As far as safety goes a high side switch is preferred.
When the high side switch is open both sides of the load are at ground potential.
With a low side switch both sides of the load are at the high side potential when the switch is open.

sylvie369

Thanks. That was a couple of really clear answers.