PRODUCT DESCRIPTION
The AD6623 is a 4-channel Transmit Signal Processor (TSP) that creates high bandwidth data for Transmit Digital-to-Analog Converters (TxDACs) from baseband data provided by a Digital Signal Processor (DSP). Modern TxDACs have achieved sufficiently high sampling rates, analog bandwidth, and dynamic range to create the first Intermediate Frequency (IF) directly.

FEATURES
   Pin Compatible to the AD6622
   18-Bit Parallel Digital IF Output
      Real or Interleaved Complex
   18-Bit Bidirectional Parallel Digital IF Input/Output
      Allows Cascade of Chips for Additional Channels
      Clipped or Wrapped Over Range
      Two’s Complement or Offset Binary Output
   Four Independent Digital Transmitters in Single Package
   RAM Coefficient Filter (RCF)
      Programmable IF and Modulation for Each Channel
      Programmable Interpolating RAM Coefficient Filter
      π/4-DQPSK Differential Phase Encoder
      3π/8-PSK Linear Encoder
      8-PSK Linear Encoder
      Programmable GMSK Look-Up Table
      Programmable QPSK Look-Up Table
      All-Pass Phase Equalizer
      Programmable Fine Scaler
      Programmable Power Ramp Unit
   High Speed CIC Interpolating Filter
   Digital Resampling for Noninteger Interpolation Rates
   NCO Frequency Translation
      Carrier Output from DC to 52 MHz
      Spurious Performance Better than –100 dBc
   Separate 3-Wire Serial Data Input for Each Channel
      Bidirectional Serial Clocks and Frames
   Microprocessor Control
   2.5 V CMOS Core, 3.3 V Outputs, 5 V Inputs
   JTAG Boundary Scan

APPLICATIONS
   Cellular/PCS Base Stations
   Micro/Pico Cell Base Stations
   Wireless Local Loop Base Stations
   Multicarrier, Multimode Digital Transmit
      GSM, EDGE, IS136, PHS, IS95, TDS CDMA, UMTS,
      CDMA2000
   Phased Array Beam Forming Antennas
   Software Defined Radio
      Tuning Resolution Better than 0.025 Hz
      Real or Complex Outputs