MAXIM DS31406

ABRIDGED DATA SHEET
19-5711; Rev 0; 12/10
DS31406
2-Input, 14-Output, Single DPLL Timing IC
with Sub-ps Output Jitter
General Description
The DS31406 is a flexible, high-performance timing IC
for diverse frequency conversion and frequency
synthesis applications. On each of its two input clocks
and fourteen output clocks, the device can accept or
generate nearly any frequency between 2kHz and
750MHz.
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 which 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.
Features
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PART
DS31406GN+
TEMP RANGE
PIN-PACKAGE
-40C to +85C
256 CSBGA
+Denotes a lead(Pb)-free/RoHS-compliant package.
SPI is a trademark of Motorola, Inc.
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
Seven Digital Frequency Synthesizers
 Produce Any 2kHz Multiple Up to 77.76MHz
 Per-DFS Clock Phase Adjust
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Three Output APLLs
 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
 Simultaneously Produce Three Low-Jitter Rates from
the Same Reference (e.g., 622.08MHz for SONET,
255/237*622.08MHz for OTU2, and 156.25MHz for
10GE)
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14 Output Clocks in Seven Groups
 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
 Two Sync Pulse Outputs: 8kHz and 2kHz
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
Ordering Information
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
Two 2/4/8kHz Frame Sync Inputs
High-Performance DPLL
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For telecom systems, the DS31406 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 DS31406 meets the requirements of
Stratum 2, 3E, 3, 4E, and 4, G.812 Types I–IV, G.813,
and G.8262.
Applications
Two Input Clocks
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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
 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.
ABRIDGED DATA SHEET
DS31406
Application Example
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ABRIDGED DATA SHEET
DS31406
Block Diagram
DS31406
SYNC1
SYNC2
FSYNC
MFSYNC
MFSYNC
PLL Bypass
DFS Muxes
Divider Muxes
DFS 1
Divider 1
APLL1
lowest jitter path
APLL2
lowest jitter path
APLL3
lowest jitter path
DFS 2
Divider 3
DFS 4
Divider 4
DFS 5
Divider 5
DFS 6
Divider 6
DFS 7
Divider 7
OC1
OC1POS/NEG
OC2
OC2POS/NEG
OC3
OC3POS/NEG
OC4
OC4POS/NEG
OC5
OC5POS/NEG
OC6
OC6POS/NEG
OC7
OC7POS/NEG
Master Clock
APLL
Microprocessor Port
(SPI Serial)
and HW Control and Status Pins
CPHA
CPOL
JTAG
CS
SCLK
SDI
SDO
JTRST
JTMS
JTCLK
JTDI
JTDO
Clock
Selector
GPIO[4:1]
status
DFS 3
Filtering, Holdover,
Hitless Switching, PBO,
Frequency Conversion,
Manual Phase Adjust
INTREQ
SRFAIL
LOCK
IC2 POS/NEG
DPLL
Frequency Scaler, 8
Activity Monitor,
Freq. Monitor,
Optional Inversion
(per input clock)
RST
TEST
SRCSW
IC1 POS/NEG
Divider 2
OSCFREQ[2:0]
Input Clock
Block
Dif Muxes
MCLKOSC
Local Oscillator
TCXO or OCXO
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ABRIDGED DATA SHEET
DS31406
Detailed Features
Input Clock Features
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Two input clocks, differential or CMOS/TTL signal format
Input clocks can be any frequency from 2kHz up to 750MHz
Supported telecom frequencies include PDH, SDH, Synchronous Ethernet, OTU-1, OTU-2, OTU-3
Per-input fractional scaling (i.e. multiplying by ND where N is a 16-bit integer and D is a 32-bit integer and
N < D) to undo 64B/66B and FEC scaling (e.g., 64/66, 238/255, 237/255, 236/255)
Special mode allows locking to 1Hz input clocks
All inputs constantly monitored by programmable activity monitors and frequency monitors
Fast activity monitor can disqualify the selected reference after a few missing clock cycles
Frequency measurement and frequency monitor thresholds with 0.2ppm resolution
Three optional 2/4/8kHz frame-sync inputs
DPLL Features
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Very high-resolution DPLL architecture
Sophisticated state machine automatically transitions between free-run, locked, and holdover states
Revertive or nonrevertive reference selection algorithm
Programmable bandwidth from 0.5mHz to 400Hz
Separately configurable acquisition bandwidth and locked bandwidth
Programmable damping factor: 1.2, 2.5, 5, 10, or 20
Multiple phase detectors: phase/frequency and multicycle
Phase/frequency locking (360 capture) or nearest edge phase locking (180 capture)
Multicycle phase detection and locking (up to 8191UI) improves jitter tolerance and lock time
Phase build-out in response to reference switching for true hitless switching
Less than 1 ns output clock phase transient during phase build-out
Output phase adjustment up to 200ns in 6ps steps with respect to selected input reference
High-resolution frequency and phase measurement
Holdover frequency averaging over 1 second, 5.8 minute and 93.2 minute intervals
Fast detection of input clock failure and transition to holdover mode
Low-jitter frame sync (8kHz) and multiframe sync (2kHz) aligned with output clocks
Digital Frequency Synthesizer Features
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Seven independently programmable DFS engines
Each DFS can synthesize any 2kHz multiple up to 77.76MHz
Per-DFS phase adjust (1/256UI steps)
Approximately 40ps RMS output jitter
Output APLL Features
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Simultaneously produce three high-frequency, low-jitter, rates from the same reference clock, e.g.,
622.08MHz for SONET, 255/237*622.08MHz for OTU2, and156.25MHz for 10GE
Standard telecom output frequencies include 622.08MHz, 155.52MHz and 19.44MHz for SONET/SDH and
156.25MHz, 125MHz, and 25MHz for Synchronous Ethernet
Very high-resolution fractional scaling (i.e., noninteger multiplication)
Less than 1ps RMS output jitter
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ABRIDGED DATA SHEET
DS31406
Output Clock Features
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14 output clock signals in seven groups
Output clock groups OC1, OC2, OC3 have a very high-speed differential output (current-mode logic,
≤ 750MHz) and a separate CMOS/TTL output (≤ 125MHz)
Output clock groups OC4–OC7 have a high-speed differential output (LVDS/LVPECL, ≤ 312.5MHz) and a
separate CMOS/TTL ouptut (≤ 125MHz)
Each output can be any frequency from < 1Hz to max frequency stated above
Supported telecom frequencies include PDH, SDH, Synchronous Ethernet, OTN, microprocessor clock
frequencies, and much more
Internal clock muxing allows each output group to slave to its associated DFS block, any of the APLLs, or
any input clock (after being divided and scaled)
Outputs sourced directly from APLLs have less than 1ps RMS output jitter
Outputs sourced directly from DFS blocks have approximately 40ps RMS output jitter
Optional 32-bit frequency divider per output
8kHz frame sync and 2kHz multiframe sync outputs have programmable polarity and pulse width and can
be disciplined by a 2kHz or 8kHz frame sync input
Per-output delay adjustment
Per-output enable/disable
All outputs disabled during reset
General Features
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SPI serial microprocessor interface
Four general-purpose I/O pins
Register set can be write protected
Operates from a 12.8MHz, 25.6MHz, 10.24MHz, 20.48MHz, 10MHz, 20MHz, 19.44MHz, or 38.88MHz
local oscillator
On-chip watchdog circuit for the local oscillator
Internal compensation for local oscillator frequency error
Note to readers: This document is an abridged version of the full data sheet. To request the full data sheet, go to
www.maxim-ic.com/DS31406 and click on Request Full Data Sheet.
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