AD8128ACPZ-R2

Overview

The AD8128ACPZ-R2 is a high-speed differential receiver and equalizer designed to compensate for transmission losses in unshielded twisted pair (UTP) Category-5 cables. It achieves an equalized bandwidth of 120 MHz for cable lengths up to 100 meters, with ±1 dB flatness extending to 70 MHz. The device operates on a ±5 V supply with a quiescent current of 24 mA per supply rail. Key electrical specifications include a slew rate of 2700 V/μs, an integrated output noise of 1.5 mV rms over a 1 GHz bandwidth, and a typical DC offset voltage error of 7 mV.

Feature Summary

• Compensates for frequency-dependent attenuation in CAT-5/CAT-5e cables using summed zero-pole pairs to approximate inverse cable response.
• Features two voltage-controlled pins for independent adjustment of broadband gain and high-frequency peaking to match specific cable lengths.
• Includes a DC offset adjust pin allowing output shifting by ±2.5 V for compatibility with DC-coupled systems.
• Supports cascading two devices in series to extend equalization capability up to 200 meters.

Applications

• Keyboard-video-mouse (KVM) switch receivers
• RGB video transmission over unshielded twisted pair (UTP) cables
• Professional video projection and distribution systems
• Security video surveillance receivers

Procurement Notes

Verify the ordering suffix corresponds to the required tape-and-reel packaging format, as Analog Devices offers multiple reel options for this component. Confirm RoHS compliance status, indicated by the 'Z' suffix in the part number. Ensure the procurement source provides valid traceability documentation for the LFCSP package variant. Check for any specific handling requirements related to moisture sensitivity levels before assembly.

Selection Notes

Select the AD8128 when designing systems requiring equalization for CAT-5 cables up to 100 meters with low noise performance. Use this component for DC-coupled applications due to its adjustable output offset. Consider cascading units if the application requires signal integrity over distances exceeding 100 meters. Ensure the design accommodates the ±5 V supply requirement and the thermal dissipation needs of the 8-lead LFCSP package.

Part Context

The AD8128 belongs to Analog Devices' line of analog equalizers specifically tuned for Category-5 cabling. It serves as a single-channel solution within a family that includes triple-channel variants like the AD8123 and AD8124. This component is often paired with drivers or dedicated receivers to form complete RGB-over-UTP transmission links, particularly in KVM infrastructure where cost-effective, long-distance video signal restoration is critical.

Replacement Considerations

Publicly confirmed substitutes within the same manufacturer's portfolio include the AD8123 and AD8124, which offer triple-channel configurations. These alternatives provide similar equalization characteristics but integrate three receivers into a single package, potentially simplifying board layout for multi-channel applications while maintaining compatibility with CAT-5 cable compensation requirements.