GENERAL DESCRIPTION

The AD6633 is a multichannel, wide bandwidth digital upconverter (DUC) with crest factor reduction (CFR) technology, which is available in 4-channel or 6-channel versions. It processes 20-bit baseband input data and generates 18-bit, wideband, real, or complex output data at up to 125 MSPS. This rate is suitable for driving digital-to-analog converters (DACs) at the first intermediate frequency (IF) directly.

FEATURES

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 a single 18-bit

output port for interleaved I and Q

All-pass phase equalizer filters (meets IS-95 requirements)

Programmable RAM coefficient FIR filters (RCF) with

resampling

FIR interpolating filters, 2 per channel

Fifth-order interpolating CIC filter, 1 per channel

Full complex NCO, 32-bit tuning resolution (fine), worst spur

better than −105 dBc, 1 per channel

Complex FIR filter for frequency equalization or additional

filtering

Output automatic gain control

Full complex composite NCO, 6-bit tuning resolution

16-bit/8-bit MicroPort (Intel® or Motorola® mode)

Serial control port (SPI®- or SPORT-compatible)

3.3 V I/O and 1.8 V core supplies

JTAG boundary scan

User-configurable, built-in, self-test (BIST) capability

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