ABRIDGED DATA SHEET
19-5712; Rev 2; 7/11
DS31415
3-Input, 4-Output, Single DPLL Timing IC
with Sub-ps Output Jitter and 1588 Clock
General Description
Features
♦
Three Input Clocks
The DS31415 is a flexible, high-performance timing IC
for diverse frequency conversion and frequency
synthesis applications. On each of its three input clocks
and four output clocks, the device can accept or
generate nearly any frequency between 2kHz and
750MHz.
♦
♦
♦
Differential or CMOS/TTL Format
Any Frequency from 2kHz to 750MHz
Fractional Scaling for 64B/66B and FEC Scaling
(e.g., 64/66, 237/255, 238/255) or Any Other
Downscaling Requirement
♦
♦
Continuous Input Clock Quality Monitoring
Three 2/4/8kHz Frame Sync Inputs
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 the
rest of the device. A flexible, high-performance digital
PLL locks to the selected reference and provides
programmable bandwidth, very high resolution holdover
capability, and truly hitless switching between input
clocks. The digital PLL is followed by a clock synthesis
subsystem that has two fully programmable digital
frequency synthesis blocks, a high-speed low-jitter
APLL, and four output clocks, each with its own 32-bit
divider and phase adjustment. The APLL provides
fractional scaling and output jitter less than 1ps RMS.
For telecom systems, the DS31415 has all required
features and functions to serve as a central timing
function or as a line card timing IC.
♦
High-Performance DPLL
♦
♦
♦
♦
Hitless Reference Switching on Loss of Input
Automatic or Manual Phase Build-Out
Holdover on Loss of All Inputs
Programmable Bandwidth, 0.5mHz to 400Hz
♦
♦
Two Digital Frequency Synthesizers
♦
♦
Produce Any 2kHz Multiple Up to 77.76MHz
Per-DFS Phase Adjustment
High-Performance Output APLL
♦
♦
Output Frequencies to 750MHz
High Resolution Fractional Scaling for FEC and
64B/66B (e.g., 255/237, 255/238, 66/64) or Any
Other Scaling Requirement
♦
Less than 1ps RMS Output Jitter
♦
♦
♦
Four Output Clocks in Two Groups
In addition the DS31415 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.
♦
Nearly Any Frequency from < 1Hz to 750MHz
Each Group Slaves to a DFS Clock, Any APLL
Clock, or Any Input Clock (Divided and Scaled)
Each Has a Differential Output (3 CML, 4 LVDS/
LVPECL) and Separate CMOS/TTL Output
32-Bit Frequency Divider Per Output
♦
♦
♦
Applications
Frequency Conversion and IEEE1588 Time/Frequency
Applications in a Wide Variety of Equipment Types
Two Sync Pulse Outputs: 8kHz and 2kHz
IEEE 1588 Clock Features
♦
♦
♦
♦
Steerable by Software with 2-8ns Time
Resolution and 2-32ns Frequency Resolution
4ns Input Timestamp Accuracy and Output
Edge Placement Accuracy
Telecom Line Cards or Timing Cards with Any Mix of
SONET/SDH, Synchronous Ethernet and/or OTN
Ports in WAN Equipment Including MSPPs, Ethernet
Switches, Routers, DSLAMs, and Base Stations
Programmable Clock and Time-Alignment I/O to
Synchronize All 1588 Devices in Large Systems
Supports 1588 OC, BC, and TC Architectures
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
General Features
DS31415GN+
256 CSBGA
-40°C to +85°C
♦
Suitable Line Card IC or Timing Card IC for
+Denotes a lead(Pb)-free/RoHS-compliant package.
SPI is a trademark of Motorola, Inc.
Stratum 2/3E/3/4E/4, SMC, SEC/EEC, or SSU
Accepts and Produces Nearly Any Frequency
from 1Hz Up to 750MHz
♦
♦
♦
♦
Internal Compensation for Local Oscillator Frequency Error
SPI™ Processor Interface
1.8V Operation with 3.3V I/O (5V Tolerant)
Maxim Integrated Products
1
Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of
any device may be simultaneously available through various sales channels. For information about device errata, go to:
www.maxim-ic.com/errata. For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or
visit Maxim’s website at www.maxim-ic.com.