8-Input, 14-Output, Dual DPLL Timing IC with Sub-ps Output Jitter and 1588 Clock
Flexible, High-Performance Timing IC is Ideal for Diverse Frequency Conversion and Frequency Synthesis Applications
The DS31408 is a flexible, high-performance timing IC for diverse frequency conversion and frequency synthesis applications.
On each of its eight input clocks and 14 output clocks, the device can accept or generate nearly any frequency between 2kHz and 750MHz. The device offers two independent DPLLs to serve two independent clock-generation paths.
The input clocks are divided down, fractionally scaled as needed, and continuously monitored for activity and frequency accuracy. The best input clock is selected, manually or automatically, as the reference clock for each of the two flexible, high-performance digital PLLs. Each DPLL lock to the selected reference and provides programmable bandwidth, very high resolution holdover capability and truly hitless switching between input clocks.
The digital PLLs are followed by a clock synthesis subsystem that has seven fully programmable digital frequency synthesis blocks, three high-speed low-jitter APLLs, and 14 output clocks, each with its own 32-bit divider and phase adjustment. The APLLs provide fractional scaling and output jitter less than 1ps RMS. For telecom systems, the DS31408 has all required features and functions to serve as a central timing function or as a line card timing IC.
In addition the IEEE 158 has an embedded IEEE® 1588 clock that can be steered by system software to follow a time master elsewhere in the system or elsewhere in the network.
This clock has all necessary features to be the central time clock in a 1588 ordinary clock, boundary clock, or transparent clock.