DESCRIPTION
The LF43891 is a video-speed digital filter that contains eight filter cells (taps) cascaded internally and a shift-and-add output stage. A 9 x 9 multiplier, three decimation registers, and a 26-bit accumulator are contained in each filter cell. The output stage of the LF43891 contains a 26-bit accumulator which can add the contents of any filter stage to the output stage accumulator shifted right by 8 bits. 8-bit unsigned or 9-bit two’s complement format for data and coefficients can be independently selected.

FEATURES
❑ 30 MHz Maximum Sampling Rate
❑ 320 MHz Multiply-Accumulate Rate
❑ 8 Filter Cells
❑ 8-bit Unsigned or 9-bit Two’s Complement Data/Coefficients
❑ 26-bit Data Outputs
❑ Shift-and-Add Output Stage for Combining Filter Outputs
❑ Expandable Data Size, Coefficient Size, and Filter Length
❑ User-Selectable 2:1, 3:1, or 4:1 Decimation
❑ Replaces Harris HSP43891
❑ 84-pin PLCC, J-Lead