Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Resolution of an audio generator

Status
Not open for further replies.

atferrari

Well-Known Member
Most Helpful Member
I am about to extend the output range of an audio generator I had designed some time ago. (CD4015 shift register with 6 weighted outputs driven by a clock frequency 12 times the desired output).

The PIC micro in charge, uses the CCP1 module, toggling one pin to materialize that clock. Found that with a 10 MHz xtal with (*4 PLL on) I can cover the 10Hz - 20 KHz range.

After running the basic calculations I started to feel deceived because at the upper range, resolution becomes quite poor (as per my expectations at least).

I've calculated what resolution I get for some output frequencies:

10 Hz >0.1 Hz
100 Hz >0.1 Hz
2000 Hz <3 Hz
5000 Hz <20 Hz
10000 Hz <40 Hz
15000 Hz <150 Hz
20000 Hz <300 Hz

Usually I tend to think of initial fancy specs (in this case it was 1Hz resolution over the whole range!!) but life brought me to reality quite quickly.

My question: thinking of using this generator in general applications, am I asking for too much? Should I settle for the above?

Just in case you feel the temptation to suggest changes in the design, please note that the only changes I am going to do is a Xtal, the associated caps and the code.

Comments appreciated.
 
My question: thinking of using this generator in general applications, am I asking for too much? Should I settle for the above?

To answer your question with another, the obvious one to ask seems to be, how good resolution do you actually need? Seems like that should drive your decision.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top