Programma Generator Sinusa
PWM SINE Wave Generator I know it has been written a lot on the subject, but this time I refer directly to Microchip AN1523: Did anybody try the examples from the above application note? I tried and for some reason the result is not as expected. Nokia emergency download driver mac windows 10 free. 1) First of all, I want to use PIC10F322 to generate the sine wave. I had no problem to generate the PWM using that provided code, but the sinus wave was not present. I decided to stay first with lookup table, then later to focus on NCO.
Digitalni generator sinusnog signala s amplitudnom, faznom i frekvencijskom modulacijom izveden DSP procesorom Tomislav Grbin Zagreb, lipanj 2011. Umjesto ove stranice umetnite izvornik Vašeg rada. Varajuce amplitude sinusa, odnosno veli´ ˇcine sin(p).
2) Because practically I had no success, I decided to simulate the code. Unfortunately the PIC10F322 is not present in simulation programs with SPICE functions. 3) Using similar code and the same Lookup Table I used PIC16F88 in ISIS Proteus and I got the PWM running. Now comes the part which gave ne troubles: the filter. • Using “Roman Black” ( ) filter with 3 capacitors and 3 resistors, I have a nice sine wave 1KHz in PROTEUS.• Using the active Sallen Key filter with OpAmp MCP602 from AN1523 page 9 the result is not a nice sinus anymore.Is that result due to Proteus? Using Sallen Key filter online calculators I notice the components value in AN1523 seems OK: Did somebody tested for real or at least simulated that Sallen Key filter with 3 capacitors and 3 resistors?
I do not understand why is not working in my simulation circuit. Practically I used LM358 instead of MCP602, but also did not give results. Did somebody test the proposed methods from AN1523? If I understand your question/problem, you have implemented (or at least you know how to implement) a sinusoidally-modulated PWM signal that (apparently) works as expected, but you did not have success when applying that digital signal to a low-pass filter similar to the one shown in AN1523. Well, I'll not try any simulation, but. I have breadboarded the filters as shown in AN1523.
Together they represent a cascade of two second-order low-pass filters. If they have Ideal values of second-order Butterworth, and if the op amp has Ideal properties, and if I feed an Ideal PWM signal modulated with 1 kHz and if the PWM cycle frequency is much larger than 1 kHz, I will expect the output of the second filter to be a 'pretty nice looking sinusoid' whose peak-to-peak value is 6 dB down from the peak-to-peak value of the fundamental (1 KHz) frequency component of digital PWM input signal. Chertezhi proektov kafe. Before I actually built them, I considered some non-ideal stuff: The component values shown in AN1523 don't actually implement a Sallen-Key lowpass approximation of a Butterworth filter. If C1 and C3 were exactly half of C2 and C4, then it the filter sections would be Butterworth, and if all component values were exactly as intended and if the op-amp were Ideal, the circuit would be the cascade of two second order Butterworth filters and the peak-to-peak output of the second one would be something like 0.5 times the peak-to-peak value of the (1 kHz modulated) digital PWM signal. (I am assuming that the PWM period is much greater than that audio modulation value.) Here's the bottom line for me (aside from possible non-exact passive component values): If you are feeding the op amp with a 5 Volt peak-to-peak (analog) sinusiod and the op amp supply voltage is 5 Volts and the op amp is explicitly specified to work in a single-supply configuration at this voltage and the op amp is explicitly specified as 'rail-to-rail,' then I should see a nice sinusoid out of the second filter section with peak-to-peak value of somewehere around 2.5 Volts. If you are not using a 'rail-to-rail' specified op amp, I would not be surprised to see something different (distorted output, output at at lower voltage; maybe even no output at all, depending on the op amp). Anyhow, here's my setup.