ABRIDGED DATA SHEET
19-5751; Rev 0; 1/11
DS31407
3-Input, 4-Output, Single DPLL Timing IC
with Sub-ps Output Jitter
General Description
Features
Three Input Clocks
The DS31407 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
Automatic or Manual Clock Selection
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.
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 Clock Phase Adjust
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
For telecom systems, the DS31407 has all required
features and functions to serve as a central timing
function or as a line card timing IC. With a suitable
oscillator the DS31407 meets the requirements of
Stratum 2, 3E, 3, 4E, and 4, G.812 Types I–IV, G.813,
and G.8262.
Four Output Clocks in Two Groups
Nearly Any Frequency from < 1Hz to 750MHz
Each Group Slaves to a DFS Clock, an APLL
Clock, or Any Input Clock (Divided and Scaled)
Each Has a Differential Output (1 CML, 1 LVDS/
LVPECL) and Separate CMOS/TTL Output
32-Bit Frequency Divider Per Output
Applications
Frequency Conversion Applications in a Wide Variety of
Equipment Types
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
Two Sync Pulse Outputs: 8kHz and 2kHz
General Features
Suitable Line Card IC or Timing Card IC for
Stratum 2/3E/3/4E/4, SMC, SEC/EEC, or SSU
Accepts and Produces Nearly Any Frequency Up
to 750MHz Including 1Hz, 2kHz, 8kHz, NxDS1,
NxE1, DS2/J2, DS3, E3, 2.5M, 25M, 125M,
156.25M, and Nx19.44M Up to 622.08M
Internal Compensation for Local Oscillator
Frequency Error
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
DS31407GN+
256 CSBGA
-40C to +85C
SPI™ Processor Interface
1.8V Operation with 3.3V I/O (5V Tolerant)
+Denotes a lead(Pb)-free/RoHS-compliant package.
SPI is a trademark of Motorola, Inc.
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.