AD8324ACPZ-REEL7

Overview

The AD8324ACPZ-REEL7 is a low-cost, single-channel line driver designed for coaxial cable applications. It operates from a single 3.3 V supply with a voltage range of 3.13 V to 3.47 V and draws up to 207 mA. The device provides a programmable gain range of 59 dB with 1 dB steps via an SPI interface. It maintains a differential output impedance of 75 Ω and supports an upper bandwidth of 100 MHz.

Feature Summary

• Digitally programmable gain control via SPI interface with 1 dB step resolution
• Maintains 75 Ω output impedance in both transmit-enable and transmit-disable states
• Integrated power-saving modes including sleep and transmit disable functions
• Supports DOCSIS 2.0 and EuroDOCSIS reverse path transmission standards

Applications

• DOCSIS 2.0 and EuroDOCSIS cable modems
• CATV set-top boxes
• CATV telephony modems
• Coaxial and twisted pair line drivers

Procurement Notes

Verify the specific package variant against project requirements, as the AD8324 family includes LFCSP and QSOP options with different temperature ranges. Confirm that the REEL7 suffix indicates tape-and-reel packaging suitable for automated assembly. Ensure compatibility with existing SPI logic levels and check for any regional distribution restrictions or lead time variations associated with this specific reel configuration.

Selection Notes

Select the AD8324ACPZ-REEL7 when designing upstream cable drivers requiring precise digital gain control and low distortion. The LFCSP package is suitable for applications needing operation between -40°C and +85°C. Consider the device's low quiescent current in sleep mode for battery-constrained systems. Ensure the design accommodates the required 1:1 output transformer for proper impedance matching and signal integrity.

Part Context

The AD8324 is part of Analog Devices' specialized amplifier portfolio, specifically engineered for cable modem and CATV infrastructure. It addresses the need for cost-effective, high-performance upstream amplification in DOCSIS environments. The component integrates digital control features typically found in more expensive discrete solutions, simplifying system architecture for manufacturers of cable modems and set-top boxes.

Replacement Considerations

Direct replacements within the AD8324 family include the AD8324ACP (QSOP) and AD8324ACPZ (LFCSP). Verify that the substitute matches the required operating temperature range and package dimensions. Ensure that any alternative device supports the same SPI programming protocol and maintains equivalent distortion performance at 61 dBmV output.

FAQ

How does the AD8324 maintain output impedance during power-down?

The device maintains a 75 Ω differential output impedance in both transmit-enable and transmit-disable conditions, eliminating the need for external back termination resistors.

What is the function of the SLEEP pin?

The SLEEP pin reduces the supply current to approximately 30 µA when driven low, providing a deep power-down state while maintaining the 75 Ω output impedance.

Can the AD8324 accept single-ended inputs?

Yes, the AD8324 accepts either differential or single-ended input signals, with a single-ended input impedance of 550 Ω.