
Analog Devices Inc. AD9545 Clock Synchronizers & Translators
Analog Devices Inc. AD9545 IEEE1588 Version 2 1pps Synchronizers and Adaptive Clock Translators support existing and emerging ITU standards for the phase, frequency, and time of day over service provider packet networks. The AD9545 devices offer high-precision, multi-output clock generator functions, and with two on-chip jitter cleaning digital PLL cores.Analog Devices AD9545's 10 clock outputs can be synchronized to any one of up to four input references. The device's digital phase-locked loops (PLLs) minimize the timing jitter associated with the external references. The digitally controlled loop and holdover circuitry continuously generate a low jitter output signal, even when all reference inputs fail.
Features
- Dual DPLL synchronizes 1Hz to 500MHz physical layer clocks providing frequency translation with jitter cleaning of noisy references
- Complies with ITU-T G.8262 and Telcordia GR-253
- Supports Telcordia GR-1244, ITU-T G.812, G.813, G.823, G.824, G.825, and G.8273.2
- Continuous frequency monitoring and reference validation for frequency deviation as low as 50ppb
- Both DPLLs feature a 24-bit fractional divider with 24-bit programmable modulus
- Programmable digital loop filter bandwidth: 10-4 to 1850Hz
- Two independent, programmable auxiliary NCOs (1Hz to 65,535Hz, resolution < 1.4 × 10−12Hz), suitable for IEEE-1588 Version 2 servo feedback in PTP applications
- Automatic and manual holdover and reference switchover, providing zero delay, hitless, or phase buildout operation
- Programmable priority-based reference switching with manual, automatic revertive, and automatic non-revertive modes supported
- 5 pairs of clock output pins with each pair useable as differential LVDS/HCSL/CML or as two single-ended outputs (1Hz to 500MHz)
- 2 differential or four single-ended input references Cross point mux interconnects reference inputs to PLLs
- Supports embedded (modulated) input/output clock signals
- Fast DPLL locking modes
- Supports a 25MHz to 52MHz crystal resonator, TCXO, or OCXO for system clock and provides for system clock frequency stability compensation
- External EEPROM support for autonomous initialization
- Single 1.8V power supply operation with internal regulation
- Built-in temperature monitor/alarm and temperature compensation for enhanced zero delay performance
Applications
- GPS, PTP (IEEE-1588), and SyncE jitter cleanup and synchronization
- Optical transport networks (OTN), SDH, and macro and small cell base stations
- OTN mapping/demapping with jitter cleaning
- Small base station clocking, including baseband and radio
- Stratum 2, Stratum 3e, and Stratum 3 holdover, jitter cleanup, and phase transient control
- JESD204B support for analog-to-digital converter (ADC) and digital-to-analog converter (DAC) clocking
- Cable infrastructures
- Carrier Ethernet
Functional Block Diagram

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Published: 2017-10-31
| Updated: 2022-10-27