Hello All,
I'm studying K10 Docs and I found no information as to the temp. stability of the internal 1,2V reference.
Does anyone know the PPM of the voltagere reference?
How good is the ADC in K10 ? So far I've been using Sigma Delta MCP3425 and it worked very well.
Generally ADCs built it microcontrollers (especially AVR) are crap so i wonder how it looks with K10?
Thanks and regards
Tomasz
Thank you guys,
MCP3425 has int. ref of 2.048V ± 0.05% , Integral Nonlinearity 10ppm FSR, Gain Error Drift of 15 ppm/°C.
The accuracy of the ref voltage is not that important to me as I calibrate the end system anyway.
My concern is the -20 to +80 temperature stability of the internal rev voltage which is not stated in the datasheet.
I wonder if I should stay with the proven MCP3425 or go for the internal ADC.
I'm measuring with 12bits 0-200mV signals at 5 samples/sec.
Regards
Tomasz
It's not clear how the MCP3425 defines 0.05% and 15ppm/C -- looks to me like over temp the total conversion error runs from +0.15% to -0.3% (figure 2-6), which is much worse than the MAX6070B.
Hi, Tomek
After factory trimmed, the range of VREF is 1.1584V to 1.2376V.
Hope my reply can help you.
Best Regards
Paul
To use your vernacular, 'crap', at +/-3.3%
I feed VrefH with a $1 REF3030AIDBZ, at 0.2% 65ppm/C. The MAX6070B is nice too...
Hi, Earl
After trimmed, you can get 0.5mV accuracy. You can find VREF_TRIM register in our reference manual.
Hope my reply can help you.
Best Regards
Paul
OK, but then 80mV drift across the temperature span. Isn't that on the order of 500ppm/C? And what about long-term-drift?