AD8321AR-REEL

Overview

The AD8321 is a digitally controlled variable gain amplifier optimized for coaxial line driving applications. It operates from a single +9 V supply and features an SPI-compatible interface for gain control over a 53.4 dB range with 0.75 dB/LSB resolution. The device maintains a constant 75 Ω output impedance during power-up and power-down conditions, eliminating the need for external transformers. It supports differential or single-ended inputs and delivers low distortion performance.

Feature Summary

• Digitally programmable gain via SPI-compatible serial interface
• Maintains constant 75 Ω output impedance in all operational states
• Integrated reverse amplifier for low-power standby mode
• Optimized for driving low-distortion signals into 75 Ω loads

Applications

• Gain programmable line drivers for cable modems
• HFC high-speed data modem upstream paths
• Interactive CATV set-top boxes
• CATV plant test equipment
• General purpose IF variable gain blocks

Procurement Notes

Verify component authenticity through authorized Analog Devices distributors or direct manufacturer channels. Confirm package integrity and pin alignment against the 20-lead SOIC specification. Review the latest datasheet revision for any updates to electrical characteristics or ordering information prior to final design integration.

Selection Notes

Select this component for designs requiring precise digital gain control in RF signal chains. Ensure the application utilizes a stable 9 V single supply for optimal performance. Verify that the load impedance matches the specified 75 Ω requirement to maintain accurate gain settings and output impedance characteristics.

Part Context

This part belongs to the AD8321 family of variable gain amplifiers manufactured by Analog Devices. It is specifically engineered for cable television and broadband communication infrastructure. The device integrates attenuator, buffer, and power amplifier stages on a single die to provide a compact solution for line driving tasks.

Replacement Considerations

Public documentation identifies the AD8320 as the predecessor model. Designers replacing legacy components should verify compatibility with input biasing and interface timing requirements. No other direct substitutes are confirmed in the provided source material.