HSP50215

The HSP50215 Digital UpConverter (DUC) is a QASK/FM modulator/FDM upconverter designed for high dynamic range applications such as cellular basestations. The DUC combines shaping and interpolation filters, a complex modulator, and Timing and Carrier NCO's into a single package. Each DUC can create a single FDM channel. Multiple DUC's can be cascaded digitally for multi-channel applications.

The HSP50215 supports both vector and FM modulation. In vector modulation mode, the DUC accepts 16-bit I and Q samples to generate virtually any quadrature AM or PM modulation format. The DUC also has two FM modulation modes. In the FM with pulse shaping mode, the 16-bit frequency samples are pulse shaped/bandlimited prior to FM modulation. No bandlimiting filter follows the FM modulator.This FM mode is useful for GMSK type modulation formats. In the FM with bandlimiting filter mode, the 16-bit frequency samples directly drive the FM modulator. The FM modulator output is filtered to limit the spectral occupancy. This FM mode is useful for analog FM or FSK modulation formats.

The HSP50215 DUC includes an NCO driven interpolation filter, which allows the input and output sample rate to have a noninteger or variable relationship. This re-sampling feature simplifies cascading modulators with sample rates that do not have harmonic or integer frequency relationships.

The HSP50215 DUC offers digital output spectral purity that exceeds 85dB at the maximum output sample rate of 52 MSPS, for input sample rates as high as 300 KSPS.

A 16-bit microprocessor compatible interface of HSP50215 is used to load configuration and baseband data. A programmable FIFO depth interrupt simplifies the interface to the I and Q input FIFOs.