Hi, all,
I've been working on an automatically-tweaked noise canceller design with my trusty code and layout Sherpas-in-training (my son and my younger daughter).
I need about 10 slow but high resolution DAC outputs for the tweaks, and I was thinking about using PWMs run from the LPC1769 processor for at least some of them.
I can close the loop on them with an on-board delta-sigma ADC (AD7708 or maybe AD7718) for an occasional sanity check.
I'd need some level shifting and stuff to make the required voltage ranges in any case, so the complexity isn't that different from using an actual DAC, and it would be a lot cheaper.
They're going into low level signal circuitry, is the only real issue, so things like the noise on the logic supply will need dealing with, e.g. by running it through a 74HCT04 powered from a clean 5V rail.
Suggestions? Pitfalls to beware of?
Cheers
Phil Hobbs