SPRZ423K October 2014 – May 2024 TMS320F28075 , TMS320F28075-Q1 , TMS320F28076
SDFM: Data Filter Output Does Not Saturate at Maximum Value With Sinc3 and OSR = 256
B, C
If the differential input of the Sigma-Delta Filter Module (SDFM) is greater than or equal to +FSR (full-scale differential voltage input range), then the output of the SDFM clips with a stream of ones. When this stream of ones is fed to a data filter that is configured as a sinc3 filter with an OSR = 256, the output of the filter does not saturate at the maximum value (16777215 in 32-bit mode or 32767 in 16-bit mode); but, instead roll over to the minimum value (–16777216 in 32-bit mode or –32768 in 16-bit mode).
Maintain the differential input of the SDFM in the specified linear input range as specified in the modulator data sheet.