ZL30117 Data Sheet
10
Zarlink Semiconductor Inc.
1.0 Functional Description
The ZL30117 SONET/SDH Line Card Synchronizer is a highly integrated device that provides timing and
synchronization for network interface cards. The DPLL is capable of locking to one of three input references and
provides a wide variety of synchronized output clocks and frame pulses.
1.1 DPLL Features
The Digital Phase-Locked Loop synchronizes to one of the qualified references and provides automatic or
manual hitless reference switching and a holdover function when no qualified references are available. It
provides a highly configurable set of features which are configurable through the serial interface. A summary of
these features are shown in Table 1.
Feature DPLL
Modes of Operation Free-run, Normal (locked), Holdover
Loop Bandwidth User selectable: 14 Hz, 28 Hz, or wideband
1
(890 Hz / 56 Hz / 14 Hz)
1. In the wideband mode, the loop bandwidth depends on the frequency of the reference input. For reference frequencies equal to or
greater than 64 kHz, the loop bandwidth = 890 Hz. For reference frequencies equal to or greater than 8 kHz and less than 64 kHz, the
loop bandwidth = 56 Hz. For reference frequencies equal to 2 kHz, the loop bandwidth is equal to 14 Hz.
Phase Slope Limiting User selectable: 885 ns/s, 7.5 μs/s, 61 μs/s, or unlimited
Pull-in Range Fixed: 130 ppm
Reference Inputs Ref0, Ref1, Ref2
Sync Inputs Sync0, Sync1, Sync2
Input Reference Frequencies 2 kHz, N * 8 kHz up to 77.76 MHz
Supported Sync Input
Frequencies
166.67 Hz, 400 Hz, 1 kHz, 2 kHz, 8 kHz, 64 kHz.
Input Reference
Selection/Switching
Automatic (based on programmable priority and revertiveness), or manual
selection
Hitless Reference Switching Can be enabled or disabled
Output Clocks diff_p/n, sdh_clk, p_clk
Output Frame Pulses sdh_fp, p_fp synchronized to active sync reference.
Supported Output Clock
Frequencies
As listed in Table 4
Supported Output Frame
Pulse Frequencies
As listed in Table 4
External Pins Status
Indicators
Lock, Holdover
Table 1 - DPLL Features
