My problem is i have to generate ramp and square waveforms with different frequencies. I planned to adjust frequency using digital potentiometer.can i use digital potentiometer to adjust frequency of waveform generated. I have tried on simulation but i cant get any response.

thank you

 

Do you want equal slopes on the charge and discharge part of the timing cycle. If so, use an opamp integrator instead of a 555.

 

my ramp is terminated ramp. i want to know can i use digipot insted of potentiometer in ramp generated. the potentiometer will control current using transistor557 to generate the terminted ramp