I have the DAC1220EVM and have it operarting quite nicely, however, the output amp rolls over when approaching max output. This is a property of the op-amp, as monitoring the DAC output directly, things go to nearly the rails. Can you suggest a more modern op-amp that will not roll over and be single supply?
Next, I wish to use 2 ea DAC1220's in the system I am designing and wondder about using a single crystal. It seems a shame to have two crystals.
Also, since the system has 2 devices each will have its own CS\. Can I CS\ both devices for simultaneous RESET?
Can I CS\ both devices for the simultaneous CAL procedure if I use a dead wait time? Can I poll only one device to determiine if they have both completed CAL?
Thank you,
Tom Burdick
Hi Tom,
We'll look over the newest single supply R2R output op amps and see what might be a better fit for you. You can supply two DAC1220s with a single TTL or CMOS clock source rather than using two crystals. You can also apply /CS to both parts at the same time if you are sending the same command - and if the two devices share a common clock source, they should finish their calibration cycle within 500ms.
Regards,
Tom