LMKDB1104Z85REXR

Overview

The LMKDB1104Z85REXR is a single-input, four-output LP-HCSL clock buffer from Texas Instruments. It provides fail-safe inputs and supports PCIe Gen 1 through Gen 7 architectures. The device features extremely low additive jitter, with maximum values of 3fs for PCIe Gen 6 and 2.1fs for PCIe Gen 7 at 156.25MHz. It operates on 1.8V or 3.3V power supplies within an ambient temperature range of -40°C to 105°C. The component includes individual output enable controls, automatic output disable, and Loss of Signal (LOS) detection.

Feature Summary

• LP-HCSL clock buffer supporting PCIe Gen 1 to Gen 7
• Extremely low additive jitter: 3fs max (Gen 6), 2.1fs max (Gen 7)
• Fail-safe inputs and automatic output disable
• Individual output enable pins and LOS detection

Applications

• High Performance Computing
• Server Motherboard
• NIC/SmartNIC
• Hardware Accelerator

Procurement Notes

Verify the specific REXR suffix indicates the VQFN-28 package variant. Confirm that the Z85 designation corresponds to the 85Ω output impedance configuration as listed in the device comparison table. Ensure compatibility with the required 1.8V or 3.3V supply rails and check for DB2000QL compliance requirements in the target design.

Selection Notes

Select this model for designs requiring a single input source distributed to four outputs with strict jitter constraints for high-speed PCIe interfaces. Choose between 85Ω (Z85) or 100Ω (Z100) variants based on the PCB trace impedance requirements. Consider the REY or RSL packages if different pin counts or form factors are needed for the application.

Part Context

This component belongs to the LMKDB family of ultra-low jitter clock buffers and muxes. It is designed to meet the stringent timing requirements of modern PCIe standards. The device ensures signal integrity through fail-safe mechanisms and flexible power-up sequences, making it suitable for critical infrastructure applications.

Replacement Considerations

LMKDB1104FS85 offers fail-safe inputs and outputs. LMKDB1104Z100 provides 100Ω output impedance. For higher channel counts, consider LMKDB1108Z85 or LMKDB1112Z85.