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What is maximum voltage PWM pins can give? can i give a vcc to 14v?

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Matteo Dario De Fazi
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3 Answers3

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Since PWM pins are digital outputs, the maximum output voltage is VCC.

Ignacio Vazquez-Abrams
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  • Or a little less, depending on load. In effect, the PWM maximum at 100% duty cycle is VOH or the high-state logic output voltage, and the data sheet will characterize what that is in relation to Vcc. – Chris Stratton Feb 13 '15 at 16:36
  • The datasheet itself does not specify a maximum in the tables, but in the charts it gives a maximum of Vcc. – Ignacio Vazquez-Abrams Feb 13 '15 at 16:43
  • There's a difference between "Maximum that could be seen" (which arguably is more like Vcc+.6v) and "Voltage that will be seen at Maximum duty cycle" - the latter is the same as the voltage of a "1", and that is not necessarily Vcc but rather depends on the load, in a way that the data sheet should at least roughly characterize (ie, voltage at a given source current, effective Rdson, etc). – Chris Stratton Feb 13 '15 at 16:45
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On a typical Arduino board, PWM pins will theoretically only ever operate at ground (+0v) or Vcc (typically +5v). PWM is a square wave, which means it alternates rapidly between those two values, aka LOW and HIGH.

With that said, if you run it with a 50% duty cycle, then the average voltage over several cycles will work out as 50% of Vcc (i.e. typically 2.5v). The same applies to other percentages. It's important to note that it's not equivalent to a 'true' analog signal though, and shouldn't be used as such.

As a side note, there are some modified Arduino clones which have a voltage selection switch. These typically let the pins operate at either 3.3v or 5v, and should affect PWM (as far as I know).

Peter Bloomfield
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+5V

I understand for higher power people driving motors trigger a MOSFET transister which normally can go to 30 volts but this unit here appears to be able to switch 100 volts: https://www.banggood.com/100V-9_4A-FR120N-Isolated-MOSFET-MOS-Tube-FET-Relay-Module-For-Arduino-p-1396252.html this unit is likely to be able handle up to 50 Khz switching frequency (based on the regular MOSFET switching speed). Anything higher you'd need GaN (Gallium Nitride) transisters as used in Class D audio amps. Anyhow 100 volts and 9.4 amps would be 940 watts of DC, or maybe 664 watts of RMS sine wave (ball park), probably I would not trust more than 300 watts through that thing mind.

Tomachi
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