SYNCHRONOUS EQUIPMENT CLOCK
STRATUM 4 CLOCK UNIT – SY0006
Model SY0006
Date: August 1, 2000
PRELIMINARY
•
INTRODUCTION
The SY0006 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
SY0006 is an excellent synchronization solution for timing, jitter and wander topics specified within ITU-T
Recommendations G.812, ETSI -ETS 300 462-4, and Bellcore GR-1244-CORE. The SY0006 is designed for
Stratum 4 applications.
•
FEATURES
A synchronization solution for timing, jitter and wander concerns in a single module.
Complies with ITU-T Recommendations G.812 and ETSI-ETS 300 462-4 and Bellcore GR-1244-CORE for
Stratum 4 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.
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 2.0 x 2.0 x 0.75 inch.
•
APPLICATION
The SY0006 performs clock regeneration as a Synchronous Equipment Clock (SEC), or STRATUM 4 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 SY0006 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 SY0006 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 4 CLOCK UNIT – SY0006
SCI
J-TAG
DSP
CPLD
EX REF1
EX REF2
DAC
1
VCXO
MUX
PD1
FLASH
RAM
÷
N
CNT1
CNT2
CONTROL
LOGIC
ALARM OUT
PLL UNLOCK
HOLDOVER
REF 1
REF 2
FREE RUN
OUT
OUTPUT
FREQUENCY
CONVERTERS
OPT OUT
Figure 1. - The functional block diagram of SY0006
•
DESCRIPTION
The SY0006 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 functional block diagram with maximum configuration is shown in figure 1. Depending on the
application, the user can specify an appropriate configuration to fit their system requirements. The basic
configuration utilizes one DPLL with a VCXO as on-board oscillator, shown in figure 1 as the shaded boxes. The
VCXO is driven by a digital-to-analog converter (DAC1) and provides the accurate and stable signal with less
power consumption. The output frequency converters scale the output frequency from the oscillator. For other
configurations, please contact Raltron.
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
±32ppm. 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 SY0006 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 SY0006 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
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 4 CLOCK UNIT – SY0006
environment effects where the clock is mounted. The SY0006 uses a VCXO 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.
Locked to Ref.2
In this mode the output of the module is phase locked to input reference 2.
The REF1 or REF2 Modes are typically used when a slave clock source is synchronized to the network. In these
modes, the SY0006 provides timing signals, which are synchronized, to one of two references inputs (REF1 or
REF2). The input reference signals may have a variety of nominal frequencies, which is typically specified by the
end user. When the modes are selected the unit goes through a reference evaluation, and then a frequency
acquisition, and finally to phase locking.
•
Input References
The SY0006 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 SY0006 module provides two output signals OUT and OPT OUT. The outputs are generated by the internal
oscillator and scaled by the output frequency converters. The performance of the module significantly depends on
the internal oscillator and special care was taken to define its specification. A Voltage Controlled Crystal Oscillator
(VCXO) is used as the internal oscillator. The frequency of the oscillator is specified according to the network
application where the SY0006 will be used. The frequency converters divide signal from the oscillator to the
specified frequencies.
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 4 CLOCK UNIT – SY0006
•
Specifications
Mechanical
Power Supply
Current Supply
Operating Temperature
Storage Temperature
Humidity
Internal Oscillators
Number of Inputs
Input reference frequency
Signal Level
Time Reference characteristics
Number of Outputs
Output 1
Output 2
Signal Level
Jitter Tolerance
Phase Transient Tolerance
Wander Generation
Frequency Output
Performance
Free run accuracy
Holdover frequency stability
Initial Offset
Temperature
Drift
DPLL bandwidth
Lock Time
Lock accuracy
±32ppm
N.A.
N.A.
N.A.
N.A
3Hz
<10sec
-11
±1x10
Bellcore: GR-1244-core 5.2
ITU-T: G.812
GR-1244-core 3.7
Bellcore: GR-1244-core 5.2
ITU-T: G.812
2” (D) x 2” (W) x 0.75” (H)
1.85” (D) x 1.85” (W) x 0.7” (H)
1.8” (D) x 1.8” (W) x 0.55” (H)
5VDC
300mA max.
-20°C to 70°C
-40° to 85°C
5% to 95% non-condensing
VCXO
2
8kHz to 77.76MHz
HCMOS/TTL Compatible
2
8kHz to 77.76MHz
8kHz to 77.76MHz
HCMOS
Hermetically Sealed Metal box
Metal Box
Module on PCB
Regulated
Other ranges available on request
General Specifications
Input Signals
User selectable
Bellcore: GR-1244-core 3.2.1.R3-1
User define
User define
Depend of the frequency output
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
GR-1244-core 5.1
ITU-T: G.812
Output Signal
Signal Quality
Performance
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 4 CLOCK UNIT – SY0006
•
Pin Assignment
On the picture below it is shown the pin-out for the SY0006. 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 REF1
GND
EX REF 2
GND
OPT OUT
GND
OUT
GND
18
17
16
15
14
13
12
11
10
1
2
3
4
5
6
7
8
9
HOLDOVER
REF 1
REF2
FREERUN
GND
ALARM OUT
CNT 1
CNT 2
PLL UNLOCK
Figure 4 – Bottom view
Pin #
1
2
3
4
6
7
8
9
5,10,12,14,16
18
11
13
17
15
Description
Holdover Signal -> the output is high when the unit is in holdover mode
Reference 1 Signal -> the output is high when the unit is using the reference 1
Reference 2 Signal -> the output is high when the unit is using the reference 2
Free-run Signal -> the output is high when the unit is in the free run mode
Alarm signal -> the output is high when there is an alarm in the module, alarm condition
ALARM OUT
is during free-run mode, holdover mode,
CNT 1
Control Input 1 -> the external input for selecting mode of the unit – see table.
CNT 2
Control Input 2 -> the external input for selecting mode of the unit – see table.
PLL Unlocked Signal -> the output is high when the unit is not locked to any of the
PLL UNLOCK
references
GND
Ground
+5V
Positive Voltage Supply
Synchronized Output -> the output of the synchronized signal, for frequency range see
OUT
table below.
Optional Output -> the secondary output of the synchronized signal, for frequency
OPT OUT
range see table below.
EX REF 1
External Reference 1 Input -> the input signal from reference 1
EX REF 2
External Reference 2 Input -> the input signal from reference 2
For other pin-out configurations contact the factory!
Name
HOLDOVER
REF 1
REF 2
FREERUN
♦
Ordering Information
SY0006
- [Input Reference Frequencies] - [Output 1] - [Output2] - [Packaging]
19.44
-> 19.44MHz
38.88
-> 38.88MHz
77.76
-> 77.76MHz
32.768
-> 32.768MHz
51.84
-> 51.84MHz
For other frequencies contact the factory!
Example: SY0006-8-19.44-8
1) F
1
/n -> is frequency of the output 1 divided by any integer number;
8
1.544
2.048
-> 8kHz
-> 1.544MHz
-> 2.048MHz
8
2.048
1
F
1
/n
-> 8kHz
-> 2.048MHz
H
M
-
Hermetically Sealed
Metal Box
Module at PCB (def)
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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