PRODUCT OVERVIEW
The AD1803/AD1804 chipset allows the implementation of a low-cost full Modem DAA Line Interface and codec with minimal external components. The AD1803 can also be used as a stand-alone codec for voice/handset/telephony applications, or as a cellular telephone interface.
The AD1803 is an Intel AC’97 Rev 2.1-compliant modem codec (refer to Intel’s AC’97 specifications at www.intel.com) with selectable AC’97 or a DSP-style serial interface.
The AD1803 codec uses high-performance sigma-delta ADC and DACs with programmable gain/attenuation. It has a digital monitor output with selectable mix from ADC and DAC channels for call progress monitoring. The AD1803 supports ring validation and wake-up interrupt output signalling. The AD1803 has programmable filters dedicated to impedance synthesis and when used with the AD1804, it provides a complete digital line termination impedance synthesis control loop.
The AD1804 is a solid-state line-side analog phone interface device that replaces a conventional discrete DAA. The AD1804 eliminates the need for transformer, relays, opto-isolators and a 2-to-4-wire hybrid. The AD1804 uses high-performance sigma-delta ADC and DACs with programmable gain/attenuation. It has digitally selectable line termination impedances.

FEATURES
  Low Power Modem Codec AD1803 and Silicon DAA AD1804
  AD1803 Can Be Used as a Stand-Alone Modem/Voice/Telephony Codec Independent of the AD1804
  Intel AC’97 Rev 2.1-Compliant Modem CodecImplementation
  AC’97 or DSP Style Serial Interface
  Supports all Modem/Fax Standards Including V.90
  Software Programmable DAA and Compliant with U.S. and International PTT Standards
  FCC and CTR21 Approved
  Capacitively Coupled Clock and Data Interface Across Isolation Barrier
  Multiple Crystal/Clock Rates Supported
  Programmable Gain, Attenuation and Mute
  On-Chip Signal Filters
     Digital Interpolation and Decimation Filters
     Analog Output Low Pass
  Programmable Sample Rates
     From 6.4 kHz to 16 kHz
     With 1 Hz, 8/7 Hz and 10/7 Hz Resolution
  Digital Monitor Speaker Output
  Integrated Ring Detector and Support for Soft Caller-ID Decode
  24-Lead TSSOP Package
  0.6 mm CMOS Technology
  Operation from 3.3 V or 5 V Supply
  Advanced Power Management
     Supports Wake-Up on Ring from D3-Cold System State
  
APPLICATIONS
  Modems (PC and Embedded)
  Voice and Telephony
  Fax Machines, Answering Machines, Speakerphones
  PBX Systems
  Smart Appliances