I am in the process of designing/building a home-brewed midi controller for an analog synth (analog except for the midi controller, that is). I have an ATmega168 chip reading midi messages, and now I need to generate a Control Voltage (CV) that is related to the note's pitch.
I need at a minimum 12-bits of precision for the digital to analog (voltage) conversion. Speed is not critical, as this will be at best approx 64 beats (pitch changes) per second or less.
The problem I keep running into is that once I select a part, I find out that it is either unavailable or that it is now obsolete. There are numerous parts that exceed my requirements (with say 24-bits etc.), but come at a high price. Or they are not available as a DIP package. Also DSPs are out for this project.
I must insist on a DIP package format, as I am un-equipped for any surface mount stuff. My eyes can barely focus on the DIP pins as it is.
So what I am looking for is a recommendation:
for a 12 to 20 bit DAC chip.
It must not obsolete or hard to find, and hopefully is reasonable. ;-) I suppose anything less than $20 US would be "reasonable" enough (