LMKDB1108Z100RKPR

Overview

The LMKDB1108Z100RKPR is an ultra-low jitter LP-HCSL clock buffer supporting PCIe Gen 1 through Gen 7 architectures. It provides one differential input and eight differential outputs with a fixed 100Ω output impedance. The device operates on 1.8V or 3.3V supplies within the -40°C to +105°C temperature range. Key electrical specifications include a maximum additive jitter of 31fs RMS (12kHz to 20MHz at 156.25MHz) and fail-safe input functionality. It is housed in a 40-pin VQFN package.

Feature Summary

• Ultra-low additive jitter: 31fs max RMS (12kHz-20MHz), 13fs for PCIe Gen 4, 5fs for Gen 5, 3fs for Gen 6, and 2.1fs for Gen 7
• Supports PCIe Common Clock (CC) and Independent Reference (IR) architectures with or without Spread Spectrum Clocking (SSC)
• Fail-safe input mechanism ensures stable operation during invalid clock signals
• Flexible power-up sequence with automatic output disable and individual output enable control

Applications

• High Performance Computing systems
• Server Motherboards
• Network Interface Cards (NIC/SmartNIC)
• Hardware Accelerators

Procurement Notes

Verify the specific suffix RKPR corresponds to the 40-pin VQFN (RKP) package and tape-and-reel delivery format. Confirm that the Z100 designation matches the required 100Ω output impedance for the target design. Ensure compatibility with the system's 1.8V or 3.3V power supply rails and SMBus interface requirements.

Selection Notes

Select this component when designing for PCIe Gen 1 to Gen 7 interfaces requiring low jitter buffering. Choose the Z100 variant specifically for 100Ω output impedance applications; use Z85 for 85Ω loads. Consider the FS variants if fail-safe outputs are also required alongside the standard fail-safe inputs. Ensure the design accommodates the 40-pin VQFN footprint and thermal pad grounding.

Part Context

This part belongs to the LMKDB11xx family of ultra-low jitter LP-HCSL buffers compliant with Intel DB2000QL specifications. While the LMKDB1120 is pin-compatible with DB2000QL, the LMKDB1108 offers a reduced channel count (8 outputs) in a smaller 40-pin VQFN package compared to the 80-pin TLGA of the 20-output variant.

Replacement Considerations

LMKDB1108Z85RKPR: Identical function but with 85Ω output impedance instead of 100Ω. LMKDB1108FSZ100RKPR: Includes fail-safe outputs in addition to the standard fail-safe inputs.