EQCO400T8

Specialized Overview

The EQCO400T8 is a multi-rate adaptive cable equalizer designed to restore signals received over Cat 5 or Cat 6 Unshielded Twisted Pair (UTP) cables. It supports data rates from 100 Mbps to 500 Mbps, including IEEE 1394b S100, S200, and S400 modes. The device operates on a single 3.3V supply with active current consumption of 42 mA and mute mode consumption of 4.25 mA. It features an LVDS differential input pair terminated by 50 Ω resistors and a CML output driver matched for 110 Ω transmission lines. The component is housed in a 16-pin, 0.65 mm pitch QFN package.

Specialized Feature Summary

• Auto-adaptive equalization using a continuous feedback loop to compensate for cable attenuation across varying signal edge rates.
• Variable gain capability allowing operation independently of the transmit amplitude of the line driver.
• Carrier detect and auto-mute functionality that disables the output driver when no incoming signal is present to reduce power consumption.
• Integrated LED driver capable of sourcing up to 3 mA to directly indicate link status without requiring external series resistors.

Specialized Applications

• Long-haul IEEE 1394b-2002 connections over Category 5 or Category 6 Ethernet cable
• General 8B/10B coded signaling transmission over UTP media
• FireWire IEEE 1394b applications at S400, S200, and S100 data rates

Specialized Procurement Notes

Verify the specific ordering suffix against official documentation to confirm temperature range and packaging details. Ensure compatibility with recommended magnetics such as Coilcraft WBC1-TLB transformers and common-mode chokes for proper isolation and performance. Confirm that the application circuit adheres to the specified PCB layout guidelines regarding trace impedance and grounding.

Specialized Selection Notes

Select this component for applications requiring signal restoration over extended distances where standard PHY reach is insufficient. Ensure the input signals are NRZ encoded, DC-balanced, and have a maximum run length of 10 bits. Verify that the connected PHY supports the required data rates and that the system design accommodates the 3.3V supply voltage requirements.

Specialized Part Context

The EQCO400T8 belongs to Microchip's family of high-speed serial bus interface components. It is specifically engineered to extend the physical layer reach of IEEE 1394b compliant systems. The device integrates analog equalization functions typically found in discrete solutions into a compact surface-mount package, simplifying board design for long-distance serial communication links.

Specialized Replacement Considerations

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

Specialized FAQ

How does the CLI pin function?

The Cable Length Indicator (CLI) pin provides an analog voltage proportional to the amount of equalization applied. A higher voltage indicates longer cable lengths or greater compensation, though it cannot be used for precise measurement due to environmental and manufacturing variations.

What is the minimum differential input voltage for full reconstruction?

The minimum differential input voltage required for a fully reconstructed output is 40 mV.

Does the EQCO400T8 support auto-crossover?

No, the EQCO400T8 does not support auto-crossover. If required, this functionality must be implemented externally to the device.