Silly Noob Question: What voltage do the PWM outputs deliver?

Geekness · Jan 31, 2017

What voltage does teensy ouptut from the PWM pins when powering an LED?
I have a number of 3mm LEDs that are all rated to max 2.6V. I'm going to use 220ohm resistors with each.

potatotron · Jan 31, 2017

Teensy 2: 5V. 220 Ohm = about 11 mA current per pin

Teensy 3.x, LC: 3.3V. 220 Ohm = about 3.5mA current per pin

Geekness · Jan 31, 2017

potatotron said:
Teensy 2: 5V. 220 Ohm = about 11 mA current per pin

Teensy 3.x, LC: 3.3V. 220 Ohm = about 3.5mA current per pin

So I should put in a voltage divider circuit (2 resistors)?
If so, would I still keep that 220ohm resistor?

potatotron · Jan 31, 2017

Geekness said:
So I should put in a voltage divider circuit (2 resistors)?
If so, would I still keep that 220ohm resistor?

Sorry but I'm not sure what you're asking. Maybe a schematic would help?

defragster · Jan 31, 2017

Just the one series resistor is what you need - to limit current/drop voltage this might show the values needed and how they relate: http://led.linear1.org/1led.wiz?VS=3.3;VF=2.6;ID=3.5

Geekness · Feb 1, 2017

Just the one series resistor is what you need - to limit current/drop voltage this might show the values needed and how they relate: http://led.linear1.org/1led.wiz?VS=3.3;VF=2.6;ID=3.5

Ah hah, Thanks for that.
The LEDs im using have a typical voltage of 2.2V, so I'll use a 330ohm resistor.

Silly Noob Question: What voltage do the PWM outputs deliver?

Geekness

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potatotron

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defragster

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