Discussion in 'Electronics & Electrics' started by nux, Mar 31, 2006.
Pre-tin the pads, use plenty of flux and buy some blutack and tweezers
The XR2206 can do ramp/sawtooth too iirc. I had looked into a few DDS based designs but was a bit too complex for what I wanted at the time.
If more than a few people want this, then maybe we could get a dozen or so boards made up properly.
The frequency output of a DDS will be very accurate so need to measure there. The set point frequency can mealy be displayed on the LCD. Output amplitute and offset voltage would be nice to have on the LCD too, but these will need to measured by the microcontroller I believed.
This looks like its going to be an interesting thing to look at.
I'm slowly piecing together a bit of a "lab" for me to use with decent DMM, CRO, etc.
Reading over some stuff, I don’t think the DDS I linked or any others of its type will be overly suitable, most don’t go much below 1mhz and we should have something that goes down to DC just about. Id like some sinewave oscillator or the likes that has excellent performance (>120db snr too much?) that covers the range we want.
Thinking about how to generate other waveforms from the sinewave I got this so far -
How about getting triangle and sawtooth from a sinewave? Doesn't sound easy to me
Can't you just pull all the different waveforms off an XR2206?
Dont think I'll get that with 0.5% thd, 0.005% would be nicer
How about this one AD5930 or this one AD5932 or AD9833. All do Sine, Triangle and Square. The last one does 0.1Hz to 12.5MHz. Pulse with variable duty cycle can be obtained with an comparator using triangle output. That just leaves Ramp to figure out.
Ive created a new thread here for discussion on designing a function generator, as this thread is getting a bit long.