1 Features
• LP-HCSL clock buffer and clock MUX that support:
– PCIe Gen 1 to Gen 6
– CC (Common Clock) and IR (Independent
Reference) PCIe architectures
– Input clock with or without SSC
• DB2000QL compliant:
– All devices meet DB2000QL specifications
– LMKDB1120 is pin-compatible to DB2000QL
• Extremely low additive jitter:
– 31fs maximum 12kHz to 20MHz RMS additive
jitter at 156.25MHz
– 13fs maximum additive jitter for PCIe Gen 4
– 5fs maximum additive jitter for PCIe Gen 5
– 3fs maximum additive jitter for PCIe Gen 6
• Fail-safe input
• Flexible power-up sequence
• Automatic output disable
• Individual output enable
• SBI (Side Band Interface) for high-speed output
enable or disable
• LOS (Loss of Signal) input detection
• 85Ω or 100Ω output impedance
• 1.8V / 3.3V ± 10% power supply
• –40°C to 105°C ambient temperature

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

3 Description
The LMKDB devices are a family of extremely-lowjitter
LP-HCSL buffers and MUX that support PCIe
Gen 1 to Gen 6 and are DB2000QL compliant. The
devices provide flexible power-up sequence, fail-safe
inputs, individual output enable and disable pins, loss
of input signal (LOS) detection and automatic output
disable features, as well as excellent power supply
noise rejection performance.
Both 1.8V and 3.3V supply voltages are supported.
For LMKDB1120, 1.8V power supply saves 250mW
power compared to 3.3V.