AD6440

a FEATURES Complete Analog Front End for ADSL Modems Part of ADI ADSL Chipset (AD20msp930) Designed to ANSI T1.413/ETSI TR238/ITU G.adsl Performance e.g., 6.1 Mbps Downstream Over 12K Ft. Suitable for CO or CPE (ATU-C and ATU-R) Includes Transmit and Receive Signal Paths: DAC: 20 MSPS 14-Bit Current Output ADC: 10 MSPS 12-Bit PGA: –6 dB–30 dB of Gain with 1 dB Steps Programmable Filters 8-Bit Auxiliary DAC for Timing Recovery Interface to 3.3 V or 5 V Digital Logic Low Power Consumption (525 mW) 80-Lead MQFP –40؇C to +85؇C Operation Analog Front End for ADSL AD6440 GENERAL DESCRIPTION The AD6440 is a complete analog front end IC (AD6440) for ADSL systems. Although part of the Analog Devices DMT chipset, it is suitable for use with digital implementations from other suppliers. As part of the AD20msp930 chipset, it complements the AD6449; together with the line driver and an external filter, they make a complete ADSL datapump, designed to comply with ANSI and ETSI standards for DMT-based ADSL. The AD6440 includes both transmit and receive paths. These include the DAC (up to 20 MSPS, allowing for oversampling of the downstream transmit signal), ADC (up to 10 MSPS), low noise PGA and filters. The filters are software configurable for both the CO and RT modes. There is an 8-bit auxiliary DAC (e.g., for timing recovery). The AD6440 has been designed to be versatile, and most blocks can be used or externally bypassed. TX[13:0] 14 CPORT 4 VCXO RX[11:0] 12 FUNCTIONAL BLOCK DIA...