SNIU028D February 2016 – September 2020 UCD3138 , UCD3138064 , UCD3138064A , UCD3138128 , UCD3138A , UCD3138A64
Here is a block diagram of the first part of the filter, with bit width information:
All values shown in the filter are signed numbers, with the most significant bit going to the sign bit. All are treated as being normalized to 1.
The main input to the filter is a 9 bit signed value from an Error ADC. It is shown on the upper left as Xn. It goes to the input for filter calculations, and it also goes to a digital comparator. The Filter provides for nonlinear calculations, with up to 7 different coefficient sets selected by the Xn value. This can be used to change the compensation of the filter with different input error ranges. For a complete discussion of this feature, see Section 4.4.6.