GENERAL DESCRIPTION
The AD6635 is a multimode, 8-channel, digital Receive Signal Processor (RSP) capable of processing up to four WCDMA channels. Each channel consists of four cascaded signal-processing elements: a frequency translator, two CIC decimating filters, and a programmable coefficient-decimating filter. Each input port has input level threshold detection circuitry for accommodating large dynamic ranges or situations where gain ranging converters are used. Quad 16-bit parallel output ports accommodate high data rate WBCDMA applications. On-chip interpolating half-band filters can also be used to further increase the output rate. In addition, each output port has a digital AGC for accommodating large dynamic ranges using smaller bit widths. The AGCs can maintain either signal level or clipping level, depending on their mode. Link port outputs are provided to enable glueless interfaces to Analog Devices’ TigerSHARC DSP core.

FEATURES
   Four 80 MSPS Wideband Inputs (14 Linear Bits Plus 3 RSSI)
   4 Real Input Ports/2 Complex Input Ports
   Processes 4 Wideband Channels (UMTS or cdma2000
      1x) or 8 GSM/EDGE, IS136 Channels
   8 Independent Digital Receivers in a Single Package
   Four 16-Bit Parallel Output Ports and Four 8-Bit Link Ports
   4 Programmable Digital AGC Loops with 96 dB Range
   Digital Resampling for Noninteger Decimation Rates
   Programmable Decimating FIR Filters
   4 Interpolating Half-Band Filters
   Flexible Control for Multicarrier and Phased Array
   Programmable Attenuator Control for Clip Prevention and
      External Gain Ranging via Level Indicator
   3.3 V I/O, 2.5 V CMOS Core
   User Configurable Built-in Self Test (BIST) Capability

APPLICATIONS
   Multicarrier, Multimode Digital Receivers
      GSM, IS136, EDGE, PHS, IS95, UMTS, cdma2000
   Micro and Pico Cell Systems, Software Radios
   Wireless Local Loop
   Smart Antenna Systems
   In-Building Wireless Telephony