MDB1900ZBQZ-TR

Overview

The MDB1900ZBQZ-TR is a zero-delay clock buffer manufactured by Microchip Technology, originally developed by Micrel. It features a fully integrated programmable PLL and distributes reference clocks for PCIe (Gen1/2/3), SATA, SAS, ESI, SMI, and Intel Quickpath Interconnect (QPI). The device accepts a single differential HCSL input and provides nineteen differential HCSL-compatible output pairs. It supports true zero-delay operation via an external feedback path and operates on a 3.3V or 2.5V supply within the commercial temperature range of 0°C to +70°C.

Feature Summary

• Supports zero-delay buffer mode for 100MHz and 133.33MHz frequencies with selectable PLL bandwidth.
• Features nineteen differential HCSL-compatible outputs controlled by eight dedicated OE# pins.
• Includes an SMBus interface for controlling output properties, enabling glitch-free assertion/de-assertion.
• Compatible with spread spectrum modulation for EMI reduction.

Applications

• PCI Express timing in Intel platforms, specifically the Romley platform
• SATA and SAS storage system timing
• ESI and SMI systems
• Intel Quickpath Interconnect

Procurement Notes

Verify component authenticity as the MDB1900ZB series was originally produced by Micrel before its acquisition by Microchip Technology. Confirm that the 'Z' suffix indicates the commercial temperature grade (0°C to +70°C) and the 'TR' suffix denotes tape and reel shipping. Ensure compliance with RoHS and PFOS standards required for the application environment.

Selection Notes

Select this part when a low-phase noise, zero-delay buffer is required for high-speed serial interfaces like PCIe Gen3 or QPI. The external feedback topology minimizes drift, making it suitable for critical applications. Ensure the design accommodates the 72-pin 10mm x 10mm QFN package and provides adequate thermal relief through the exposed pad.

Part Context

This component is part of the MDB1900Z family, designed to meet Intel's DB1900Z specification. The specific designation G20746-002 identifies it within Intel's ecosystem. It functions in conjunction with synthesizers such as the CK410B+, CK509B, or CK420BQ to provide reference clocks to multiple agents in complex system architectures.

Replacement Considerations

The MDB1900ZBQY is the industrial temperature variant (-40°C to +85°C) of this component. For pin-compatible upgrades with improved phase jitter performance, consider the 9ZXL1950D series from Microchip Technology.

FAQ

How is the zero-delay buffer mode achieved?

Zero-delay operation is achieved using an external feedback path connecting the FB_OUT pins to the FB_IN pins, which maintains low drift for critical applications.

What is the maximum frequency supported in fanout buffer mode?

The device supports fanout buffer mode for clock frequencies between 0 and 250MHz.

Can multiple devices share the same SMBus segment?

Yes, the device offers nine selectable SMBus addresses, allowing multiple devices to share the same SMBus segment.