PIC18F with DAC?

[king.oslo]

Hello there,

I have some experience using C18 compiler for PIC18F-ICs.

For my next project, I need to use a DAC as PWM cant do what I want it to. Unless any of you can think of a circuit that can convert PWM to constant voltage.

If not, does any of the PIC18Fs have DAC?

Thanks.

Kind regards,
Marius

 

[smanches]

I believe DACs are only on the dsPICs. The ds30 and ds33.

You can use PWM to do constant voltage, as any waveform can be smoothed out to it's RMS value. But the DAC route might be easier depending on what you are actually using it for.

 

[king.oslo]

Would you smooth out PWM with a capacitator?

 

[smanches]

Yes, a capacitor would smooth out a PWM signal to a fairly flat level. The bigger the capacitor, the smoother it will be, but it will take longer to change voltage when the pwm changes. A smaller one will change faster, but will have more ripple in the output. That's the trade-off.