TI E2E Community
Precision Data Converters
Precision Data Converters Forum
FIR filter in ADS1178 D-S ADC
For a research project we need to accurately simulate in software the ADS1178 D-S ADC modulator and FIR decimation filter. The ADS1178 data sheet indicates that the FIR filter is a multi-stage filter with total decimation factor of 64 and the document provides frequency and step response plots.
I have designed a digital FIR decimation filter trying to replicate the frequency response plots but encountered some issues that are most likely due to the fact that I do not have information on the filter topology, number of stages, order and decimation factor of each stage, processing between the stages, etc.
My questions are:
1. Does this information exist in any document published by TI? If it exists, can you provide a link?
2. I understand that some of this information cannot probably be shared, but Is it possible to get any additional infomation about the FIR filter as described above, even top level?
I appreciate your help.
Details of the ADS1178/1278 digital filter outside of what the data sheet states are part of the "secret sauce" of the part and cannot necessarily be shared. As you mentioned it is a FIR filter which uses over 70 "taps" or conversion results to reside at its final result.The benefit of this topology is the steep roll off at the Nyquist frequency while the downside is the heavy latency.
I understand your restrictions and appreciate your quick answer, thank you.
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.