Fronthaul Switches
5G networks are becoming more flexible and more interoperable with the disaggregation of the base band unit (BBU). The Ethernet-based fronthaul, using the eCPRI protocol, now connects the separated functional units with time synchronization that is 10x more stringent than in past generations.
SiTime MEMS timing products provide a complete solution – one that is more robust and accurate, capable of meeting the timing challenges of 5G RAN. Our Elite Platform® Super-TCXOs and Emerald™ OCXOs provide the stability engine in fronthaul switches, and our Cascade™ network synchronizer manages the IEEE 1588 loop and eCPRI/SyncE interface.
SiTime MEMS Timing Benefits
Complete MEMS clock treePrecision MEMS TCXO Stratum 3E MEMS OCXO MEMS clock IC/PLL |
More robust in real world conditions4x better dF/dT for accurate IEEE 1588 Resistant to airflow, heat, vibration Smart clock monitoring and hit switching for redundancy |
Integrated MEMS, easy to useNo external quartz No quartz reliability issues No cover or shielding needed |
Fronthaul Switch Block Diagram
MEMS Timing Solutions for Ethernet-based Fronthaul or IP RAN Switch
| Devices | Function | Key Features |
|---|---|---|
|
Super-TCXO
SiT535x 1 to 220 MHz
|
Reference clock for jitter cleaner and IEEE 1588 | ±100 ppb, ±1 ppb/°C 105°C |
|
OCXO
SiT57xx 1 to 60 MHz
|
Reference clock for jitter cleaner and IEEE 1588 | ±5 ppb, ±0.04 ppb/°C |
|
Network Synchronizer
SiT9514x 8 kHz to 2.1 GHz
|
Ethernet, processor | 4-in, 11-out, 4-PLL |
|
Differential XO
SiT9501 25 to 644.53125 MHz
SiT9375 25 to 644.53125 MHz
|
Ethernet, FPGA | 0.1 to 0.2 ps jitter, 105°C |
MEMS Timing Outperforms Quartz
Better Stability |
Better Frequency Slope |
|---|---|
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Better Vibration Resistance |
Better Aging |
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Better Allan Deviation |
Better PSNR (Power Supply Noise Rejection) |
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Watch Video: SiTime MEMS Timing Solutions for Open RAN
Application Notes and Papers
- Synchronization System Performance Benefits of Precision MEMS TCXOs under Environmental Stress Conditions
- Adaptive Drift Compensation for Holdover Oscillators
- AN10063 TCXO and OCXO Stability and System Impact Beyond Rated Temperature
- AN10064 Improved System Performance with Digital Frequency Tuning in Precision Super-TCXOs
- AN20003 SiT9514x Power Supply Noise Rejection
- AN20011 SiT9514x Dynamic Control of Outputs
- AN10052 IEEE 1088 Precision Time Protocol (PTP) in ITU-T Standards
- See full list of related applications notes
Videos
