Fixed-frequency oscillator for 155.52 MHz reference clocks
The Texas Instruments LMK61E0-155M52SIAT is a fixed-frequency clock oscillator delivering a 155.52 MHz output — the standard reference rate for SONET/SDH, 10 Gigabit Ethernet, and optical transport network (OTN) line cards. It operates from a 3.135 V to 3.465 V supply rail and draws 162 mA typical.
Supply and temperature envelope for system timing
The 3.135 V to 3.465 V supply range covers both 3.3 V nominal rails with margin for ripple and dropout — a common requirement when the oscillator shares a rail with FPGAs or ASICs that pull the supply down during logic transitions. With a 162 mA supply current at 155.52 MHz, the oscillator's power dissipation is roughly 0.53 W at 3.3 V.
The base product number is LMK61, which covers the family of fixed-frequency oscillators in the 6-QFM footprint.