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I'm confused as I have seen a triangle waveform referred to in terms of PWM but a triangle waveform does not actually modulate the pulse width.

Is a triangle waveform a type of pulse width modulation?

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  • \$\begingroup\$ Are you asking if a triangle signal can be generated using PWM? Or if triangle waveform can be used as PWM-like carrier? \$\endgroup\$ – Eugene Sh. Dec 5 '19 at 16:28
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    \$\begingroup\$ A real pulse width modulated signal can sometimes look triangular due to limitations in rise and fall times but, theoretically no. \$\endgroup\$ – Andy aka Dec 5 '19 at 16:31
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    \$\begingroup\$ Good question ... \$\endgroup\$ – Mitu Raj Dec 5 '19 at 16:38
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    \$\begingroup\$ Perhaps you've seen a triangle waveform compared with the analog input signal to create a PWM output? A triangle waveform generator block plus comparator block does the PWM trick. \$\endgroup\$ – glen_geek Dec 5 '19 at 16:40
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    \$\begingroup\$ In the early days of inverters (switch mode power supplies), a fixed frequency triangular waveform was used as the base switching frequency. That analog waveform was compared to a fed-back version of the output - an error term. The output of that comparator was the PWM signal that was used to drive the switching transistors. What glen_geek said. \$\endgroup\$ – SteveSh Dec 5 '19 at 16:44
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Is a triangle waveform a type of pulse width modulation?

No, without pulse widths, there can't be a PWM.

Especially: Since the average of the triangle waveform is constant / can't be parameterized, there's nothing to modulate.

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  • \$\begingroup\$ Thank you. That's what I though, it's really strange to see it referred to as a PWM. I'm going to accept this as true unless someone gives a solid reason why it is false. \$\endgroup\$ – SeanJ Dec 6 '19 at 21:57
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The comparison of a triangle wave to a sine wave is a technique that has been used to generate a pwm waveform that simulates a sine wave.

enter image description here

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Is a triangle waveform a type of pulse width modulation?

Close .

It is the Modulator which has a binary output by comparing an analog voltage.

It is can also be done with a sawtooth waveform which is often harder to generate at high frequency.

enter image description here

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    \$\begingroup\$ I assume that using a triangle vs sawtooth wave generate PWM that is different, but still "close enough", that the average duty cycles are the same? \$\endgroup\$ – Steve Dec 6 '19 at 6:54

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