Active production — a clean BOM line for a 312.5 MHz reference clock
The LMK61A2-312M50SIAR is an active-production XO (Standard) from Texas Instruments' LMK61XX series, delivering a fixed 312.5 MHz LVDS output from a silicon resonator — no quartz crystal, no mechanical aging drift, and a faster startup than a crystal oscillator.
LVDS output and the 100-ohm termination rule
The LVDS output delivers a differential pair that expects a 100-ohm termination resistor at the receiver — without it the common-mode range shifts and the signal integrity degrades. The 196 mA max supply current includes the output driver bias; when the Enable/Disable pin pulls the output to high-Z, the supply drops to 136 mA max. The 3.3 V supply rail is the only power input — no separate core or I/O voltage. The silicon resonator base means the part starts up in microseconds rather than milliseconds, which matters for applications where the clock must be stable before the downstream PLL locks.
Footprint and board integration — standard 5x7 mm oscillator package
Surface-mount mounting with tape-and-reel packaging suits automated pick-and-place assembly. No external load capacitors or crystal matching network are needed — the silicon resonator and output driver are self-contained in the module.