Hello ! my friend, now i can run the ads1298 sucessfully.
But when measuring the noise of each channel, i found it a little bit noisy of channel 1-6.
the noise ampltude of ch1 to ch6 is about 190 uV. and the peak-to-peak range is less than 10uV .
When it comes to the ch7 and ch8 ,the noise amptitude is about 30uV, peak-to-peak range is also less than 10uV .
So fat I havn't found the reason .Could some one give me some advise ?（the data is even negative，it means that the INXN is a little bit higher than INXP ）
MY test condition: 25℃, sampling rate:500SPS , High Resolution mode and PGA = 1,TQFP package ;
Here are some charts which drown by EXCEL:
A student waiting for your help from GuangZhou ,CHINA.
Welcome to the Precision Data Converters Forum! Is this a board of your own design or are you using the ADS1298 hardware from ADS1298ECGFE-PDK? It looks to me like you might actually be measuring the offset of the ADS1298 in your first graph above. The offset error can be as hign as 500uV, so your ~192uV would be in line with the data sheet specifications for the ADS1298. The Vpp of your second graph, at 500SPS, PGA = 1 in High Res mode looks good.
Thank you TOM!
it's a board of my own design.
I think i misunderstanded the concept of input refered noise before your apply;
Would you mean that ( CHnSET BIT[ 2:0 ] = 001 for offset or noise measurement ) :
OFFSET ERROR = the absolute voltage amplitude
INPUT REFERED NOISE = the VPP value ?
Thanks you very very much!
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with respect to these materials. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.