LMK1D1212RHAR

Clock Buffers, Drivers Overview

The LMK1D1212RHAR is a low additive jitter LVDS buffer from Texas Instruments, packaged in a 40-pin VQFN (6-mm × 6-mm). It distributes one of two selectable clock inputs to 12 pairs of differential LVDS outputs. The device supports input frequencies up to 2 GHz and operates on a supply voltage ranging from 1.71 V to 3.465 V. Key electrical specifications include a maximum propagation delay of 575 ps, an output skew of 20 ps, and a maximum random additive jitter of 60 fs RMS at 156.25 MHz within a 12-kHz to 20-MHz integration range. It functions within an industrial temperature range of –40°C to 105°C.

Clock Buffers, Drivers Feature Summary

• 2:12 differential buffer with universal input compatibility for LVDS, LVPECL, LVCMOS, HCSL, LP-HCSL, and CML signals.
• Low additive jitter performance (< 60 fs RMS) and very low phase noise floor (-164 dBc/Hz typical).
• Configurable output amplitude via AMP_SEL pin, providing standard 350-mV or boosted 500-mV LVDS swing.
• Integrated fail-safe input and hysteresis to prevent random oscillation when no input signal is present.

Clock Buffers, Drivers Applications

• Telecommunications and networking systems
• Medical imaging equipment
• Test and measurement instruments
• Wireless infrastructure components

Clock Buffers, Drivers Procurement Notes

Verify the RHA suffix confirms the 40-pin VQFN package with a 6.00 mm × 6.00 mm body size. Confirm the 'I' designation indicates the industrial temperature grade spanning –40°C to 105°C. Ensure the datasheet revision matches current design requirements, as pin assignments for IN0_P and IN0_N were updated in Revision A compared to earlier versions.

Clock Buffers, Drivers Selection Notes

Select the LMK1D1212RHAR when 12 differential LVDS outputs are required from a single clock source. Use this component if the application demands high-frequency operation up to 2 GHz with minimal skew. Consider the boosted mode feature if the downstream receivers require higher voltage swings than standard LVDS provides. Verify that the power supply environment supports the 1.8-V, 2.5-V, or 3.3-V operating ranges.

Clock Buffers, Drivers Part Context

This part belongs to the LMK1D121x family, which also includes the LMK1D1216 offering 16 outputs in a larger 48-pin package. Unlike the LMK1D1208 variants that offer individual output enable control, the LMK1D1212 utilizes global output enable control via pin configuration. It serves as a fan-out buffer designed specifically for driving 50-Ω transmission lines with high signal integrity.

Clock Buffers, Drivers Replacement Considerations

The LMK1D1212RGZR is a pin-compatible alternative within the same family but housed in a 48-pin VQFN package containing 16 outputs instead of 12. Direct substitution requires verifying board space constraints and ensuring the unused pins are managed correctly. Other family members like the LMK1D1208 differ significantly in output count and enable control mechanisms.