AD8328ARQZ-REEL

Overview

The AD8328 is a digitally controlled variable gain amplifier designed for coaxial line driving in DOCSIS and EuroDOCSIS reverse path systems. It operates from a single 5 V supply and accepts differential or single-ended inputs. The device provides a programmable voltage gain range of 59 dB with 1 dB steps, achieving an upper bandwidth of 107 MHz. Key performance metrics include −57.5 dBc SFDR at 21 MHz and −54 dBc at 65 MHz, with an output noise level of 1.2 nV/√Hz at minimum gain.

Feature Summary

• Supports DOCSIS and EuroDOCSIS standards for reverse path transmission
• Gain programmable in 1 dB steps over a 59 dB range via SPI interface
• Maintains 300 Ω differential output impedance for transformer matching
• Includes sleep mode reducing quiescent current to 20 μA

Applications

• DOCSIS and EuroDOCSIS cable modems
• CATV set-top boxes
• Coaxial and twisted pair line drivers

Procurement Notes

Verify the specific package type (LFCSP or QSOP) as the base part number covers multiple form factors. Confirm that the REEL suffix indicates tape-and-reel packaging if required by assembly equipment. Ensure the component meets the operating temperature range of −40°C to +85°C for the intended environment.

Selection Notes

Select this component for applications requiring precise digital gain control in upstream cable paths. The 59 dB range accommodates varying distances between the modem and head-end. Ensure the design supports the required 5 V supply and SPI communication lines. Consider the thermal dissipation capabilities of the chosen package for continuous operation at maximum gain.

Part Context

The AD8328 is part of Analog Devices' lineup of low-cost amplifiers optimized for coaxial line driving. It is specifically engineered to meet the stringent distortion and noise requirements of MCNS-DOCSIS and EuroDOCSIS standards. The device integrates an 8-bit serial interface for gain adjustment and features low-power modes to minimize energy consumption during idle periods.

Replacement Considerations

Publicly confirmed substitutes are not available in the provided documentation. When evaluating alternatives, ensure compatibility with the 5 V supply, SPI interface timing, and 59 dB gain range. Verify that replacement devices maintain similar SFDR and noise performance at 65 MHz to comply with DOCSIS specifications.