Chipkit Max32 PWM voltage

Created Wed, 28 Mar 2012 21:07:49 +0000 by unbornchaos

unbornchaos

Wed, 28 Mar 2012 21:07:49 +0000

Hello, Iam just starting to work with my new Chipkit max 32.

I am generating a pwm signal with my chipkit through port 9. For a specific application i need to convert this pwm signal into an analog output using a circuit. I need the analog output to scale from 0V to 5V but the max pwm voltage i can get from the Max32 is 3.3V.

Is there anyway i can make the pwm output come out at 5V and not 3.3V?

I know the microcontroller works with 3.3V so i figured the pwm signal max voltage cant be higher than that amount,I wanted to ask the community if there is any possibility?

P.D. I am trying to evade using a voltage amplifying circuit.

Jacob Christ

Thu, 29 Mar 2012 06:45:28 +0000

I think this will be pretty tough without an amplifier of some kind. If you don't need to go to zero volts, you could tie the 3.3V power to 5V power and float your grounds.

There may be some open drain pins on the PIC32 that could be used to pull down a pin pulled up to 5V though a 5K-10K resistor, but this would limit your current drive capability of your PWM signal.

An easy way to do this would be to just use a tiny logic buffer (or inverter) that is powered off of 5V. Most 5V logic gates will take a 3.3V input as a logic high thus converting you 3.3V PWM to a 5V PWM. No additional analog magic needed.

Jacob