AD9873JS

Overview

The AD9873JS is a mixed-signal frontend (MxFE) integrated circuit designed for cable modem and set-top box applications. It integrates a 232 MHz quadrature digital transmitter featuring a 12-bit DAC, direct digital synthesis, and programmable clock multipliers. The receiver section comprises four analog-to-digital converters: dual 8-bit ADCs at 16.5 MSPS for IQ demodulation, a 10-bit ADC at 33 MSPS for IF signals, and a 12-bit video ADC with an auxiliary multiplexer. Operating on a single 3.3 V supply, the device supports MCNS-DOCSIS and DVB standards within a 100-lead MQFP package.

Feature Summary

• Integrates a 232 MHz quadrature digital upconverter with a 12-bit TxDAC+ and Direct Digital Synthesis
• Includes four receiver ADCs: dual 8-bit (16.5 MSPS), one 10-bit (33 MSPS), and one 12-bit (33 MSPS)
• Features a programmable PLL clock multiplier and sigma-delta outputs for external component control
• Provides direct interface pins for AD8321/AD8323 programmable gain amplifier cable drivers

Applications

• Cable and Satellite Systems
• Digital Communications
• Data and Video Modems
• Set-Top Boxes
• Broadband Wireless Communication

Procurement Notes

Verify the specific ordering suffix against the manufacturer's current documentation to confirm pin compatibility and temperature range. The AD9873JS designation corresponds to the commercial operating temperature range of 0°C to 70°C housed in a Metric Quad Flatpack (MQFP). Ensure that any replacement components match the original 100-lead MQFP footprint and electrical specifications.

Selection Notes

Select this component when designing systems requiring a low-cost, single-chip solution for both upstream transmission and downstream reception in broadband networks. The device is suitable for environments where power dissipation and board space are constrained. Verify that the system clock requirements align with the internal PLL capabilities and that the available ADC resolutions meet the dynamic performance needs of the target modulation schemes.

Part Context

The AD9873JS belongs to the Analog Devices AD9873 family of mixed-signal frontends. This series was developed to address the integration challenges in digital set-top boxes and cable modems by consolidating multiple discrete signal processing functions into a single silicon die. The JS variant specifically denotes the commercial grade version packaged in the MQFP format, distinguishing it from other potential industrial or evaluation variants.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.