MDB1900ZCQZ

Overview

The MDB1900ZCQZ is a zero-delay clock buffer manufactured by Microchip Technology, originally designed by Micrel. It features a fully integrated programmable PLL and distributes reference clocks for PCIe (Gen1/Gen2/Gen3), SAS, SATA, ESI, SMI, and Intel Quickpath Interconnect (QPI). The device accepts a differential HCSL input and provides nineteen differential HCSL-compatible output pairs. It operates on a single supply voltage of 2.375V to 3.465V and supports frequencies up to 133.33MHz in zero-delay mode or 250MHz in fanout mode. The component is housed in a 72-pin 10mm x 10mm QFN package with an exposed pad.

Feature Summary

• Integrated Zero-Delay Buffer: Supports 0ps input-to-output delay variation in PLL mode for 100MHz and 133.33MHz frequencies.
• Programmable PLL: Features selectable high/low bandwidth modes and bypass options to filter jitter and minimize peaking.
• SMBus Control: Includes nine selectable SMBus addresses for software control of output enable/disable and delay tuning.
• Spread Spectrum Tolerance: Compatible with spread spectrum modulation for EMI reduction.

Applications

• PCI Express timing for Intel Romley platforms
• SATA/SAS storage system timing
• Intel Quickpath Interconnect (QPI)
• ESI and SMI systems

Procurement Notes

Verify the manufacturer origin, as the MDB1900ZC was originally developed by Micrel before its acquisition by Microchip Technology. Confirm that the specific ordering suffix 'QZ' corresponds to the commercial temperature range (0°C to +70°C) and tape-and-reel shipping format. Ensure compatibility with existing PCB layouts regarding the 72-VFQFN package dimensions and thermal pad requirements.

Selection Notes

Select this component when a true zero-delay buffer is required for PCIe Gen1 through Gen3 or QPI applications. The internal feedback path eliminates the need for external PCB routing for the feedback loop, simplifying board design. Choose between the QY suffix for industrial temperature ranges (-40°C to +85°C) or the QZ suffix for commercial ranges based on environmental constraints. Ensure the design accommodates the 19 differential outputs and SMBus interface requirements.

Part Context

The MDB1900ZC is part of the DB1900Z specification family, designed to work in conjunction with synthesizers like the CK410B+, CK509B, or CK420BQ. It serves as a pin-compatible upgrade to previous generations while offering improved phase jitter performance. The device is compliant with RoHS and PFOS standards and utilizes a 100% matte tin lead finish.

Replacement Considerations

The MDB1900ZCQY is the industrial temperature variant of this component. For direct replacements, consider the 9ZXL1950D series from Renesas, which offers enhanced performance and is a derivative of the DB1900Z architecture.