DESCRIPTION

The LF43881 is a video-speed digital filter that contains eight filter cells (taps) cascaded internally and a shift-and-add output stage. An 8 x 8 multiplier, three decimation registers, and a 26-bit accumulator are contained in each filter cell. The output stage of the LF43881 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 two’s complement format for data and coefficients can be independently selected.

FEATURES

? 25 MHz Maximum Sampling Rate

? 320 MHz Multiply-Accumulate Rate

? 8 Filter Cells

? 8-bit Unsigned or Two’s Complement Data

? 8-bit Unsigned or Two’s Complement 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 HSP43881

? 84-pin PLCC, J-Lead