CLC5903 CLC5903 Dual Digital Tuner/AGC Literature Number: SNWS005D N Na t i on a l S e m i c o n du c t o r CLC5903
Dual Digital Tuner / AGC
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0 General Overview Features The CLC5903 Dual Digital Tuner / AGC IC is a two channel
digital downconverter (DDC) with integrated automatic gain
control (AGC). The CLC5903 is a key component in the
Enhanced Diversity Receiver Chipset (EDRCS) which
includes one CLC5903 Dual Digital Tuner / AGC, two
CLC5957 12-bit analog-to-digital converters (ADCs), and two
CLC5526 digitally controlled variable gain amplifiers
(DVGAs). This system allows direct IF sampling of signals up
to 300MHz for enhanced receiver performance and reduced
system costs. В„ 78MSPS Operation В„ Low Power, 145mW/channel, 52 MHz, Dec=192 В„ Two Independent Channels with 14-bit inputs В„ Serial Daisy-chain Mode for quad receivers В„ Greater than 100 dB image rejection В„ Greater than 100 dB spurious free dynamic range В„ 0.02 Hz tuning resolution В„ User Programmable AGC with enhanced Power Detector The CLC5903 is an enhanced replacement for the CLC5902
in the Diversity Receiver Chipset (DRCS). The main
improvements relative to the CLC5902 are a 50% increase in
maximum sample rate from 52MHz to 78MHz, a 62%
reduction in power consumption from 760mW to 290mW,
and the added flexibility to independently program filter
coefficients in the two channels. A block diagram for a
DRCS-based narrowband communications system is shown
in Figure 1. В„ Channel Filters include a Fourth Order CIC followed by
21-tap and 63-tap Symmetric FIRs В„ FIR filters process 21-bit Data with 16-bit Programmable
Coefficients В„ Two independent FIR coefficient memories which can be …
