AD5398, 120mA Current sinking DAC With Reduced Current Range
I'm working with the AD5398. I don't need the full 120mA range of the device. Is it possible to get the full 10bit resolution over a smaller current range, say 20mA? What would be the proper way to do this?
Regarding your question – You can certainly operate the AD5398 at a reduced current settling but unfortunately you will no longer be able to get 10 bits of resolution. It might be worth considering the AD5750 ? This ADI IC is a current/voltage output driver with 20mA and 24mA sink capability. Primarily targeting industrial applications, It operates from dual supplies ±12 V to ±24 V. This product does not integrate a DAC however but you could choose a 10/12-bit external DAC (like the AD5620 for example) and drive the AD5750 directly. You will need to set-up the device in +/-20mA Mode. (software selectable over the SPI interface)
The advantage of this IC is very low drift and low Total Unadjusted error as well as a small footprint.
http://www.analog.com/en/amplifiers-and-comparators/instrumentation-amplifiers/ad5750/products/product.html
http://www.analog.com/en/amplifiers-and-comparators/instrumentation-amplifiers/ad5750-1/products/product.html
http://www.analog.com/en/digital-to-analog-converters/da-converters/ad5620/products/product.html
-Liam