The LMK5B33216 meets the challenging requirements for advanced high-speed communication networks by leveraging the BAW technology. The LMK5B33216 integrates a VCBO into APLL3 (the BAW APLL) to achieve ultra-low phase noise and jitter. The VCBO is a high-Q BAW resonator that is co-packaged with the LMK5B33216 silicon IC. Output clocks generated from the BAW APLL achieve excellent output RMS jitter and phase noise performance for the telecom industries.

The VCBO operates at 2500MHz (± 100ppm) and can be divided down to output 312.5MHz clocks with 42fs typical and 60fs maximum RMS jitter (12kHz to 20MHz) regardless of the DPLL reference clock frequency and jitter characteristics. The remaining APLLs are LC-VCOs and can be used for additional frequency domains outside the Ethernet domain or when the output frequency cannot be sourced from the BAW APLL.

Figure 4-3 shows the composition of the BAW resonator technology. The structure includes a thin layer of piezoelectric film between two metal films and other layers that confine the mechanical energy. The BAW utilizes this piezoelectric transduction to generate a vibration, therefore, outputting a clock frequency. For more information on the BAW, refer to our list of BAW Application Notes.

Figure 4-3 Basic Structure of a Bulk Acoustic Wave Resonator

The BAW technology in the LMK5B33216 greatly reduces the phase noise and RMS jitter of the synchronized output clock, thereby meeting and exceeding the challenging system requirements for 400Gbps and 800Gbps systems by a comfortable margin.