4-Channel, 80 MSPS WCDMA Receive Signal Processor (RSP) AD6635 FEATURES Programmable Attenuator Control for Clip Prevention and Four 80 MSPS Wideband Inputs (14 Linear Bits Plus 3 RSSI) External Gain Ranging via Level Indicator 4 Real Input Ports/2 Complex Input Ports 3.3 V I/O, 2.5 V CMOS Core Processes 4 Wideband Channels (UMTS or cdma2000 User Configurable Built-in Self Test (BIST) Capability 1x) or 8 GSM/EDGE, IS136 Channels APPLICATIONS 8 Independent Digital Receivers in a Single Package Multicarrier, Multimode Digital Receivers Four 16-Bit Parallel Output Ports and Four 8-Bit Link Ports GSM, IS136, EDGE, PHS, IS95, UMTS, cdma2000 4 Programmable Digital AGC Loops with 96 dB Range Micro and Pico Cell Systems, Software Radios Digital Resampling for Noninteger Decimation Rates Wireless Local Loop Programmable Decimating FIR Filters Smart Antenna Systems 4 Interpolating Half-Band Filters In-Building Wireless Telephony Flexible Control for Multicarrier and Phased Array FUNCTIONAL BLOCK DIAGRAM RAM TO A AND B rCIC2 PORT A CIC5 COEFFICIENT OUTPUT RESAMPLER FILTER PORTS RCF OUTPUTS LINK PORT INA 13:0 CHANNEL 0 CHANNELS 0, 1, 2, 3 OR EXPA 2:0 TO A AND B NCO I PARALLEL OUTPUT IENA N RAM PORTS PORT rCIC2 COEFFICIENT CIC5 P RESAMPLER FILTER CH A INTERPOLATING LIA-A U HALF-BAND FILTER, T CHANNEL 1 LIA-B INTERLEAVING & AGC CH A AND B NCO OUTPUT MUX M TO A AND B CIRCUITRY RAM A rCIC2 OUTPUT CIC5 COEFFICIENT T RESAMPLER PORTS FILTER R INB 13:0 CHANNEL 2 CH B INTERPOLATING I PORT B EXPB 2:0 HALF-BAND FILTER, NCO X INTERLEAVING & AGC LINK PORT IENB RAM rCIC2 OR CIC5 COEFFICIENT TO A AND B RESAMPLER PARALLEL FILTER OUTPUT RCF OUTPUTS LIB-A PORTS PORT CHANNEL 3 CHANNELS 0, 1, 2, 3 LIB-B NCO PORT C TO C AND D RAM rCIC2 OUTPUT CIC5 COEFFICIENT 8-BIT DSP RESAMPLER PORTS FILTER RCF OUTPUTS LINK PORT INC 13:0 CHANNELS 4, 5, 6, 7 CHANNEL 4 OR EXPC 2:0 NCO TO C AND D I OUTPUT 16-BIT RAM IENC N PORTS PARALLEL rCIC2 COEFFICIENT CIC5 P OUTPUT RESAMPLER FILTER CH C INTERPOLATING LIB-A U HALF-BAND FILTER, CHANNEL 5 T LIB-B CH C AND D INTERLEAVING & AGC NCO OUTPUT MUX M TO C AND D CIRCUITRY RAM A rCIC2 OUTPUT CIC5 COEFFICIENT PORTS T RESAMPLER FILTER PORT D R IND 13:0 CH D INTERPOLATING CHANNEL 6 I 8-BIT DSP HALF-BAND FILTER, EXPD 2:0 NCO LINK PORT X INTERLEAVING & AGC IEND OR RAM rCIC2 TO C AND D CIC5 COEFFICIENT RCF OUTPUTS RESAMPLER OUTPUT 16-BIT FILTER CHANNELS 4, 5, 6, 7 LID-A PORTS PARALLEL CHANNEL 7 OUTPUT LID-B NCO RSP BUILT-IN (BIST) MICROPORT OR SERIAL SYNCA CLK EXTERNAL CLK SELF-TEST CIRCUITRY PORT CONTROL SYNCB SYNC. SYNCC CIRCUIT SYNCD REV. 0 Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. may result from its use. No license is granted by implication or otherwise Tel: 781/329-4700 www.analog.com under any patent or patent rights of Analog Devices. Trademarks and Fax: 781/326-8703 2003 Analog Devices, Inc. All rights reserved. registered trademarks are the property of their respective companies.AD6635 GENERAL DESCRIPTION High dynamic range decimation filters offer a wide range of The AD6635 is a multimode, 8-channel, digital Receive Signal decimation rates. The RAM-based architecture allows easy Processor (RSP) capable of processing up to four WCDMA reconfiguration for multimode applications. channels. Each channel consists of four cascaded signal-process- The decimating filters remove unwanted signals and noise from ing elements: a frequency translator, two CIC decimating filters, the channel of interest. When the channel of interest occupies and a programmable coefficient-decimating filter. Each input less bandwidth than the input signal, this rejection of out-of-band port has input level threshold detection circuitry for accommo- noise is called processing gain. By using large decimation dating large dynamic ranges or situations where gain ranging factors, processing gain can improve the SNR of the ADC by converters are used. Quad 16-bit parallel output ports accom- 30 dB or more. In addition, the programmable RAM coefficient modate high data rate WBCDMA applications. On-chip filter allows antialiasing, matched filtering, and static equaliza- interpolating half-band filters can also be used to further tion functions to be combined in a single, cost-effective filter. increase the output rate. In addition, each output port has a Half-band interpolating filters at the output are used in various digital AGC for accommodating large dynamic ranges using applications, especially in WCDMA or cdma2000 applications, smaller bit widths. The AGCs can maintain either signal level or to increase the output rate from 2 to 4 the chip rate. The clipping level, depending on their mode. Link port outputs are AD6635 is equipped with four independent automatic gain provided to enable glueless interfaces to Analog Devices control (AGC) loops for direct interface to a RAKE receiver. TigerSHARC DSP core. The AD6635 is compatible with standard ADC converters, such The AD6635 is part of Analog Devices SoftCell Multicarrier as the AD664x, AD943x, AD923x, and the AD922x families of transceiver chipset designed for compatibility with Analog Devices data converters. The AD6635 is also compatible with the family of high sample rate IF sampling ADCs (AD9238/AD6645 AD6600 Diversity ADC, and hence can be designed into exist- 12-bit and 14-bit). The SoftCell receiver comprises a digital ing systems that use AD6600 ADCs. receiver capable of digitizing an entire spectrum of carriers and digitally selecting the carrier of interest for tuning and channel selection. This architecture eliminates redundant radios in wireless base station applications. 2 REV. 0