Ladder waveform generator

[meep]

Hi

Im looking for a Ladder waveform ckt that can be interfaced with a microntroller. Ive seen a MCU with a DAC and it can supply a ladder waveform as an output and the user can vary the frequency to his liking. So my question is, Is there any other way of doing this without using a DAC :?:

thank u

 

[echo47]

Ladder - do you mean a waveform that looks like stairs?

You could feed several short current pulses into a capacitor. Then another pulse that somehow discharges the capacitor.

 

[meep]

cn i make its output look like this?

 

[eltonjohn]

Well the ancient CMOS technique basically was to make a counter and to tight the outputs to resistors that add in a point ..Well this comes down to making a home made DAC .A Dac you know! is not a COMPLICATED circuit .

 

[meep]

so it basically falls down to an R-2R network?

 

[echo47]

Ten positive current pulses into a capacitor, then ten negative current pulses, and you get that voltage waveform. No DAC required.

Is there some reason that you don't wan't to use a DAC?