SYNCHRONOUS EQUIPMENT CLOCK
STRATUM 3E CLOCK UNIT – SY0004
Model SY0004
Date: March 21-00
PRELIMINARY
•
INTRODUCTION
The SY-0004 is an accurate time and frequency source that has been designed as a module level subsystem. The
module is designed to work within ATM, SONET, SDH, and wireless systems where synchronization is vital. The
SY-0004 is an excellent synchronization solution for timing, jitter and wander topics specified within ITU-T
Recommendations G.812, and Bellcore GR-1244-CORE. The SY-0004 is designed for Stratum 3E applications,
but also has certain features that can make it useful for other kinds of system clocks.
•
FEATURES
A synchronization solution for timing, jitter and wander concerns in a single module.
Complies with ITU-T Recommendations G.812 - Type III and Bellcore GR-1244-CORE for Stratum 3E
applications.
Supports four modes of operation: Locked to Reference 1, Locked to Reference 2, Holdover and Free-run.
Accepts reference inputs from two independent sources from 8 kHz to 77.76 MHz.
Provides two outputs up to 77.76 MHz and one up to 2.048MHz.
Loop filtering utilizing application specific software in the digital signal processor (DSP).
Continuously monitors and evaluate input reference signals.
Creates a history buffer for Holdover mode operation.
Manual or Automatic selection between timing modes.
Alarm and status signal.
Host interface and JTAG port.
Small dimensions of 3.9 x 2.4 x 0.9 inch.
•
APPLICATION
The SY-0004 performs clock regeneration as a Synchronous Equipment Clock (SEC), or STRATUM 3E in ATM,
SDH, PDH, and SONET networks. It is designed for manufacturers of network equipment, especially Access
Switches, Core Switches, Cross Connects, Digital Multiplexers-Exchangers, and SDH/SONET equipment. The unit
is also suitable for PCS, WLL, and Wireless Base Stations. Wherever a Timing unit with high performance
specifications is required, the SY0004 can be integrated into the network system and provide all necessary
frequencies and interfaces. The input stage can receive two different input reference signals at various rates from
4 kHz to 77.76 MHz. An optional application can be achieved by integrating the SY0004 with a low cost GPS
receiver and locking it to the GPS 1 pps output signal.
RALTRON ELECTRONICS CORP.
§
10651 N.W.19 St
§
Florida 33172
§
U.S.A.
Tel: 305 593-6033
§
Fax: 305-594-3973
§
e-mail: sales@raltron.com
§
Internet: http:/www.raltron.com
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SYNCHRONOUS EQUIPMENT CLOCK
STRATUM 3E CLOCK UNIT – SY0004
Alarms and Statuses
T.S
.
OCXO
Ex.Ref.1 1
Ex.Ref.2
MUX,
FPD,
Counters
&
Logic
OUT 3
DSP
(RAM,
FLASH)
DDS
Output
PLL
Synthesizer
OUT 2
OUT 1
Control Inputs
SPI
JTAG
Figure 1. - The functional block diagram of SY0004
•
DESCRIPTION
The SY0004 synchronization module is a Digital PLL (DPLL), which utilizes application specific software in the
digital signal processor (DSP). The DSP is complemented by fast hardware logic (CPLD) where all multiplexers,
counters, dividers, phase detectors, output frequency converters and other control logic circuits are completely
implemented. The module uses Direct Digital Synthesis (DDS) technique combine with high stability OCXO in
order to provide accurate and fast response in the DPLL and eliminate requirements for an OCXO with high pull.
The output of the DDS is connected to an output PLL synthesizer that generates two output signals. The third
output comes from DDS. The SY0004 provides several other features such as: switching between the references
inputs on the basis of monitoring and estimation of the input signals and internal state diagram; real time
calculation of the filtering algorithm for jitter and wander in according to the approved standards; alarm, status and
messaging functions; controlling the internal references in regard of frequency vs. temperature (utilizing
temperature measurement with T.S.), aging and calibration effects etc. The three wires serial communication
interface - SPI provides flow of messages between the module and host computer. The JTAG interface provides
an easy way for re-programming the unit with future versions of software without removing from the systems.
ü
The module operates in the following four timing modes:
Free-run
In this mode the unit is unlocked to either of the inputs. The accuracy of the output frequencies in this mode is
±4.6ppm. Free-run mode is typically used when a master clock source is required, not valid history of data for the
Holdover mode, or immediately following system power-up before network synchronization is achieved. In the
Free-run Mode, the SY0004 provides timing and synchronization signals that are based on the accuracy of on-
board oscillators only, and are not synchronized to the reference signals.
Holdover
In this mode the module has lost its reference inputs and is utilizing stored timing data, called history, to control the
output frequency. Holdover Mode is typically used while network synchronization is temporarily disrupted. In
Holdover Mode, the SY0004 provides timing, based on data from the history buffer, while unlocked to an external
reference signal. The history data is determined while the device is locked to an external reference signal. The
stability of the output signal in holdover mode depends primarily on the stability of on-board oscillator and should
be better then 10ppb in the first 24 hours. The SY0004 uses an OCXO as an on-board oscillator but other types of
oscillators are available.
Locked to Ref.1
In this mode the output of the module is phase locked to input reference 1.
RALTRON ELECTRONICS CORP.
§
10651 N.W.19 St
§
Florida 33172
§
U.S.A.
Tel: 305 593-6033
§
Fax: 305-594-3973
§
e-mail: sales@raltron.com
§
Internet: http:/www.raltron.com
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SYNCHRONOUS EQUIPMENT CLOCK
STRATUM 3E CLOCK UNIT – SY0004
Locked to Ref.2
In this mode the output of the module is phase locked to input reference 2.
•
Input References
The SY00004 module accepts two input references EX REF1 and EX REF2. End users can specify the
frequencies within a range of 8 kHz to 77.76 MHz. The input reference signals are HCMOS/TTL levels with timing
characteristic in according to Bellcore GR-1244-core 3.2.1.R3-1 or equivalent standards. Please note that the end
user must specify the two input frequencies at the time of order.
•
Output Signals
The SY0004 module provides three output signals OUT1, OUT2 and OUT3. The first two outputs are generated by
the output PLL synthesizer and scaled by the output frequency converters and the third one is generated by DDS.
The performance of the module significantly depends on the internal oscillator and special care was taken to
define its specification. A high stability Oven Controlled Crystal Oscillator (OCXO) is used as the internal oscillator
in order to provides stable internal reference in all operating conditions.
•
Specifications
General Specifications
Mechanical
Power
Environment
3.9” (D) x 2.4” (W) x 0.9” (H)
5VDC, 3W after warm up time
Operating Temperature
Storage Temperature
Humidity
Ovenized Crystal Oscillator (OCXO)
2
8kHz to 77.76MHz
HCMOS/TTL Compatible
Bellcore: GR-1244-core 3.2.1.R3-1
3
8kHz to 77.76MHz
8kHz to 77.76MHz
8kHz,1.544MHz or2.048MHz
Metal box, 24p dual-in-line
-20°C to 60°C
-40° to 85°C
5% to 95% non-condensing
High Stability SC-cut OCXO
User selectable
Input Signals
Output Signal
Signal Quality
Performance
Internal Oscillator
Number of Inputs
Input reference frequency
Signal Level
Time Reference characteristics
Number of Outputs
Output 1
Output 2
Output 3
Jitter Tolerance
Phase Transient Tolerance
Wander Generation
Wander Tolerance
Jitter Generation and Transfer
Wander Transfer
Frequency Output
Performance
Free run accuracy
Holdover frequency stability
Initial Offset
Temperature
Drift
Phase Build-Out
DPLL bandwidth
Lock Time
Lock accuracy
±4.6ppm
±1x10
for 24hours
-8
±1x10
±8x10
±1x10
-9
-9
-9
HCMOS, frequency user define
HCMOS, frequency user define
HCMOS, frequency user define
Bellcore: GR-1244-core 4.2
ITU-T: G.812
Bellcore: GR-1244-core 4.4
Bellcore: GR-1244-core 5.3
ITU-T: G.812
Bellcore: GR-1244-core 4.3
ITU-T: G.812
Bellcore: GR-1244-core 5.5
ITU-T: G.812
Bellcore: GR-1244-core 5.4
ITU-T: G.812
GR-1244-core 5.1
ITU-T: G.812
Bellcore: GR-1244-core 5.2
ITU-T: G.812
Bellcore: GR-1244-core 5.2
ITU-T: G.812
Bellcore: GR-1244-core 5.2
ITU-T: G.812
Bellcore: GR-1244-core 5.2
ITU-T: G.812
Bellcore: GR-1244-core 5.7
ITU-T: G.812
GR-1244-core 3.7
0.001Hz
<700sec
-11
±1x10
RALTRON ELECTRONICS CORP.
§
10651 N.W.19 St
§
Florida 33172
§
U.S.A.
Tel: 305 593-6033
§
Fax: 305-594-3973
§
e-mail: sales@raltron.com
§
Internet: http:/www.raltron.com
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SYNCHRONOUS EQUIPMENT CLOCK
STRATUM 3E CLOCK UNIT – SY0004
•
Pin Assignment
On the picture below it is shown the pin-out for the SY0004.The design is done in such a way that is can support
basically any other pin-out without changes in the hardware. For other pin-out requirement please contact the
Raltron.
+5V
EX. REF.1
GND
EX. REF.2
GND
OUT 2
OUT 3
GND
N/C
OUT 1
GND
PLL UN
24
23
22
21
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
9
10
11
12
HOLDOVER
REF 1
REF 2
FREERUN
GND
N/C
CLK
DX
DR
ALARM OUT
CNT 1
CNT 2
Figure 4 – Bottom view
Pin #
1
2
3
4
6, 16
7
8
9
10
11
12
13
5,14,16,17,20,22
24
15
18
19
23
21
Name
HOLDOVER
REF 1
REF 2
FREERUN
N/C
CLK
DX
DR
ALARM OUT
CNT 1
CNT 2
PLL UN
GND
+5V
OUT 1
OUT 2
OUT 3
EX REF1
EX REF 2
Description
Holdover Signal -> the unit is in holdover mode, Signal Output
Reference 1 Signal -> the unit is enslaved to the reference 1, Signal Output
Reference 2 Signal -> the unit is enslaved to the reference 2, Signal Output
Freerun Signal -> the unit is in the free run mode, Signal Output
Not connected
Serial Clock -> host interface, clock pin, Input
Data Transmit -> host interface, transmit pin, Output
Data Receive -> host interface receive pin, Input
Alarm signal, Signal Output
Control Input 1 -> the external input for selecting mode of the unit, Input
Control Input 2 -> the external input for selecting mode of the unit, Input
PLL Unlocked Signal -> the PLL is not locked, Signal Output
Ground
Positive Voltage Supply
Synchronized Output 1-> the primary output from PLL synthesizer, Output
Synchronized Output 2-> the secondary output from PLL synthesizer, Output
Synchronized Output 3-> the secondary output from DDS, Output
External Reference 1 Input -> the input from reference 1, Input
External Reference 2 Input -> the input from reference 2, Input
For other pin-out configurations contact the factory!
RALTRON ELECTRONICS CORP.
§
10651 N.W.19 St
§
Florida 33172
§
U.S.A.
Tel: 305 593-6033
§
Fax: 305-594-3973
§
e-mail: sales@raltron.com
§
Internet: http:/www.raltron.com
th
SYNCHRONOUS EQUIPMENT CLOCK
STRATUM 3E CLOCK UNIT – SY0004
♦
Ordering Information
SY0004
- [Input Reference Frequencies] - [Output 1] - [Output 2] –[Output 3]
8
1.544
2.048
-> 8kHz
-> 1.544MHz
-> 2.048MHz
19.44
38.88
77.76
51.84
-> 19.44MHz
-> 38.88MHz
-> 77.76MHz
-> 51.84MHz
8
19.44
38.88
77.76
51.84
-> 8kHz
->19.44MHz
->38.88MHz
->77.76MHz
-> 51.84MHz
8
1.544
2.048
-> 8kHz
-> 1.544MHz
-> 2.048MHz
For other frequencies contact the factory!
Example: SY0004-8-19.44-19.44-8
•
Mechanical dimensions
Figure 5 – The mechanical dimensions.
Figure 5 shows the mechanical dimension of the SY0004 module. The module can be supplied in three different
types of packaging:
ü
Hermetically sealed metal box
ü
Metal box
ü
Module without packaging
The dimensions shown on the picture are valid for first and second type of packaging, the actual dimensions for
the third type are 2.2 x 3.75 x 0.75” keeping the pin-out dimensions the same for all of three. The label on the
module shows part number, factory name, week and year of production.
RALTRON ELECTRONICS CORP.
§
10651 N.W.19 St
§
Florida 33172
§
U.S.A.
Tel: 305 593-6033
§
Fax: 305-594-3973
§
e-mail: sales@raltron.com
§
Internet: http:/www.raltron.com
th
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