The 82P33731 Synchronous Equipment Timing Source (SETS) for 10G Synchronous Ethernet (SyncE) provides tools to manage timing refer-
ences, clock generation and timing paths for SyncE based clocks, per ITU-T G.8264 and ITU-T G.8262. 82P33731 meets the requirements of ITU-T
G.8262 for synchronous Ethernet Equipment Clocks (EECs) and ITU-T G.813 for Synchronous Equipment Clocks (SEC). The device outputs low-jit-
ter clocks that can directly synchronize 100GBASE-R, 40GBASE-R, 10GBASE-R and 10GBASE-W and lower-rate Ethernet interfaces; as well as
CPRI/OBSAI, SONET/SDH and PDH interfaces.
The 82P33731 accepts six differential reference inputs and six single ended reference inputs that can operate at common GNSS, Ethernet,
SONET/SDH and PDH frequencies that range from 1 Pulse Per Second (PPS) to 650 MHz. The device also provides two Alternate Mark Inversion
(AMI) inputs for Composite Clock (CC) signals bearing 64 kHz, 8 kHz and 0.4 kHz synchronization information. The references are continually moni-
tored for loss of signal and for frequency offset per user programmed thresholds. All of the references are available to both Digital PLLs (DPLLs). The
active reference for each DPLL is determined by forced selection or by automatic selection based on user programmed priorities and locking allow-
ances and based on the reference monitors and LOS inputs.
The 82P33731 can accept a clock reference and an associated phase locked sync signal as a pair. DPLL1 can lock to the clock reference and
align the frame sync and multi-frame sync outputs with the paired sync input. The device allows any of the differential or single ended reference inputs
to be configured as sync inputs that can be associated with any of the other differential or single ended reference inputs. The input sync signals can
have a frequency of 1 PPS, 2 kHz, 4 kHz or 8 kHz. This feature enables DPLL1 to phase align its frame sync and multi-frame sync outputs with a sync
input without the need use a low bandwidth setting to lock directly to the sync input.
The DPLLs support three primary operating modes: Free-Run, Locked and Holdover. In Free-Run mode the DPLLs synthesize clocks based on
the system clock alone. In Locked mode the DPLLs filter reference clock jitter with the selected bandwidth. In Locked mode, the long-term output fre-
quency accuracy is the same as the long term frequency accuracy of the selected input reference. In Holdover mode, the DPLL uses frequency data
acquired while in Locked mode to generate accurate frequencies when input references are not available.
The 82P33731 requires a system clock for its reference monitors and other digital circuitry. The frequency accuracy of the system clock deter-
mines the frequency accuracy of the DPLLs in Free-Run mode. The frequency stability of the system clock determines the frequency stability of the
DPLLs in Free-Run mode and in Holdover mode; and it affects the wander generation of the DPLLs in Locked mode.
When used with a suitable system clock, DPLL1 meets the frequency accuracy, pull-in, hold-in, pullout, noise generation, noise tolerance, tran-
sient response, and holdover performance requirements of the following applications: ITU-T G.8262/G.813 EEC/SEC options 1 and 2, Telcordia GR-
FEATURES .............................................................................................................................................................................. 1
RECOMMENDATIONS FOR UNUSED INPUT AND OUTPUT PINS ............................................................................................................. 9
3.2.1 System clock .................................................................................................................................................................................... 13
3.2.2 Modes of operation .......................................................................................................................................................................... 13
3.2.3.2.1 Loss of Signal (LOS) Monitoring .................................................................................................................... 22
3.2.3.2.3 Frequency Monitoring .................................................................................................................................... 23
3.2.3.3.4 Input Clock Loss of Signal ............................................................................................................................. 25
3.2.4 DPLL Locking Process ..................................................................................................................................................................... 25
3.2.4.1 Fast Loss .......................................................................................................................................................................... 25
3.2.4.2 Fine Phase Loss ............................................................................................................................................................... 25
3.2.4.3 Hard Limit Exceeding .......................................................................................................................................................
3.2.4.4 Locking Status ..................................................................................................................................................................
APLL1 and APLL2 ............................................................................................................................................................................
Input and output Phase control ........................................................................................................................................................
3.2.8.1 DPLL1 and DPL2 Phase offset control .............................................................................................................................
3.2.8.2 Input Phase control ..........................................................................................................................................................
3.2.8.3 Output Phase control ........................................................................................................................................................
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4 POWER SUPPLY FILTERING TECHNIQUES ................................................................................................................. 32
ABSOLUTE MAXIMUM RATING ................................................................................................................................................................... 40
8.3.1 AMI Input / Output Port .................................................................................................................................................................... 41
8.3.2 CMOS Input / Output Port ................................................................................................................................................................ 42
8.3.3 LVPECL / LVDS Input / Output Port ................................................................................................................................................. 43
8.3.3.1 PECL Input Port ............................................................................................................................................................... 43
8.3.3.2
LVPECL Output Port .................................................................................................................................................... 44
8.3.3.2.1 LVPECL Termination for 3.3 V ...................................................................................................................... 44
8.3.3.2.2 LVPECL Termination for 2.5 V ...................................................................................................................... 45
8.3.4 LVDS Input / Output Port ................................................................................................................................................................. 46
8.3.4.1 LVDS Input Port ............................................................................................................................................................... 46
8.3.4.2 LVDS Output Port ............................................................................................................................................................. 47
8.3.6 Wiring the Differential Input for Single-Ended Levels ....................................................................................................................... 49
JUNCTION TEMPERATURE ......................................................................................................................................................................... 39
REVISION HISTORY .............................................................................................................................................................