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 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 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 is used to load configuration and baseband data. A programmable FIFO depth interrupt simplifies the interface to the I and Q input FIFOs.

• Output Sample Rates Up to 52 MSPS (48 MSPS Industrial); Input Data Rates Up to 3.25 MSPS
• I/Q Vector, FM, and Shaped FM Modulation Formats
• 32-Bit Programmable Carrier NCO; 30-Bit Programmable Symbol Timing NCO
• Programmable I and Q, 256 Tap, Shaping FIR Filters with Interpolation by 4, 8 or 16
• Interpolation Filter Up Samples Shaping Filter Output to Output Sample Rate Under NCO Control
• Processing Capable of >90dB SFDR
• Cascade Input for Multiple Channel Transmissions
• 16-Bit µProcessor Interface for Configuration and User Data Input

• Single or Multiple Channel Digital Software Radio Transmitters (Wide-Band or Narrow-Band)
• Base Station Transceivers
• Operates with HSP50214 in Software Radio Solutions
• Compatible with the HI5741 D/A Converter
• HSP50215EVAL Evaluation Board Available Ordering Information