AD6439

a Discrete Multitone (DMT) Coprocessor for ADSL Chipsets AD6439 FEATURES Component in Analog Devices’ AD20msp918 ADSL Chipset Designed to ANSI T1.413 Issue 2/ETSI TR238/ITU G.992.1 and G.992.2 Higher Performance Improved Data Rates or Longer Reach Suitable for CO or Residence (ATU-R and ATU-C) Performs All DMT Functions and Operations Trellis Coding Echo Cancellation Symmetric Transforms (512 Point) Flexible Allocation of Tones Upstream/Downstream Supports Symmetric Services (SDSL) Increased Upstream (e.g., 1 Mbps) Supports ADSL Over ISDN (Shifted U/S) Strict Filters for Spectral Compatibility 128-Lead MQFP –40؇C to +85؇C, 3.3 V Operation, 1.1 W GENERAL DESCRIPTION The AD6439 Discrete Multitone (DMT) Coprocessor is part of Analog Devices ADSL solution, a series of flexible, standardsbased chipsets for creating high performance ADSL and SDSL modems that implement a superset of standard Category 2 functionality. A high performance alternative to the AD6436 DMT Coprocessor, the AD6439 meets the functionality requirements of ANSI T1.413 Category 2 (trellis coding, echo cancellation), but is considerably more versatile. It implements both transmit and receive paths (trellis coding/decoding, IFFT/FFT, filtering and echo cancellation). Symmetric transforms allow flexible allocation of upstream and downstream bandwidth, including symmetric data rates. Improved digital filters exceed the requirements of T1.413 and deliver strict spectral masks (e.g., for VDSL compatibility). FUNC...