Overview: HSP43220
Data Sheet February 1999 File Number
2486.7 Decimating Digital Filter
The HSP43220 Decimating Digital Filter is a linear phase low pass decimation filter which is optimized for filtering narrow band signals in a broad spectrum of a signal processing applications. The HSP43220 offers a single chip solution to signal processing applications which have historically required several boards of ICs. This reduction in ponent count results in faster development times as well as reduction of hardware costs. The HSP43220 is implemented as a two stage filter structure. As seen in the block diagram, the first stage is a high order decimation filter (HDF) which utilizes an efficient sample rate reduction technique to obtain decimation up to 1024 through a coarse low-pass filtering process. The HDF provides up to 96dB aliasing rejection in the signal pass band. The second stage consists of a finite impulse response (FIR) decimation filter structured as a transversal FIR filter with up to 512 symmetric taps which can implement filters with sharp transition regions. The FIR can perform further decimation by up to 16 if required while preserving the 96dB aliasing attenuation obtained by the HDF. The bined total decimation capability is 16,384. The HSP43220 accepts 16-bit parallel data in 2’s plement format at sampling rates up to 33 MSPS. It provides a 16-bit microprocessor patible interface to simplify the task of programming and three-state outputs to allow the connection of several ICs to a mon bus. The HSP43220 also provides the capability to bypass either the HDF or the FIR for additional flexibility.
