Multi-channel (Digital) Transmit Signal Processor (TSP) with VersaCREST™ Crest Reduction Engine

The AD6633 is a multi-channel, wide-bandwidth (Digital) Transmit Signal Processor (TSP) with VersaCREST™ crest reduction engine. It processes digital baseband input data and generates wideband, real or complex output data. It drives Intermediate Frequency (IF) sampling Digital to Analog Converters (DACs) at sample rates up to 125 Mega Samples Per Second (MSPS). Up to six wideband modulated carriers per package can be achieved from a single output port. Devices may be connected together for additional channels by using multiple packages. Interpolation, anti-imaging filtering, all pass equalization, and NCO tuning functions are combined in a single, cost-effective device which includes the VersaCREST™ crest factor reduction engine.

Each VersaCREST™ wideband channel contains a peak-to-average compensation block that reduces Power Amplifier (PA) requirements. By minimizing infrequent peaks in Code-Division Multiple-Access (CDMA) signals, a PA with one-half to one-quarter the previously necessary power capacity can be used. This is done within standard signal quality requirements, and significantly lowers system cost.

VersaCREST is a trademark of Analog Devices Inc.

APPLICATIONS

* Cellular/PCS basestations

* Micro/pico cell basestations

* Multicarrier cdma2000®, WCDMA, TD-SCDMA basestations

* Broadband wireless access head ends (LMDS, MMDS)

* Software defined radios

* High speed signal processing applications

* 4 or 6 wideband digital upconverter channels

* VersaCREST™ crest reduction engine reduces demands on external power amplifiers

* One 20-bit complex input port (I/Q interleaved), shared among 4 or 6 processing channels

* Two 18-bit output ports for parallel I and Q, or interleaved I and Q on a single port

* All-pass phase equalizer filters (meets cdma2000 requirements)

* Programmable RAM coefficient FIR filters (RCF) with resampling