SYNCHRONOUS EQUIPMENT
SONET MINIMUM CLOCK - SY0003
SY0003
Date: November 15, 2000
•
INTRODUCTION
The SY0003 is an accurate time and frequency source that has been designed as a module level subsystem for
easy incorporation into SONET/SDH systems or network elements. The SY0003 is an advanced synchronization
solution for timing, jitter and wander issues in accordance with specification for SONET Minimum Clock (SMC)
given by BellCore GR-253-CORE and BellCore GR-1244-CORE.
•
FEATURES
A synchronization solution for timing, jitter and wander concerns in a single module.
Complies with Bellcore GR-1244-CORE and GR-253-CORE for SMC 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 0.55 inch.
•
APPLICATIONS
The SY0003 performs clock regeneration as a Synchronous Equipment Clock (SEC), and is particularly designed
for SONET equipment and network elements. However, SY0003 can be used in any other telecommunication
equipment where synchronization is necessary if the performance allowed.
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
SONET MINIMUM CLOCK - SY0003
ALARMS
OUT 2
XO
T.S
.
Ref. 1
Ref. 2
Cnt. 0
Cnt. 1
MUX,
FPD,
Counters
&
Logic
DSP
DAC
(RAM,
FLASH)
VCXO
OUT 1
MAN./AUTO
RS 232
JTAG
Figure 1. - The functional block diagram of SY0003
•
DESCRIPTION
The SY0003 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. 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. The second output is provided by free running crystal oscillator.
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
±20ppm. 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 SY0003 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 SY0003 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
environment effects where the clock is mounted. The SY0003 uses an 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.
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
SONET MINIMUM CLOCK - SY0003
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 SY0003 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 SY0003 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 SY0003 module provides two output signals OUT and OPT OUT. The first outputs are generated by the
internal oscillator and scaled by the output frequency converters if necessary. The second output is coming from
free running crystal oscillator. The performance of the module significantly depends on the internal oscillator and
special care was taken to define its specification. A high quality Crystal Oscillator (VCXO) is used as the internal
oscillator. The frequency of the oscillator is specified according to the network application where the SY0003 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
th
SYNCHRONOUS EQUIPMENT
SONET MINIMUM CLOCK - SY0003
•
PIN DESCRIPTION
+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
Bottom View
Pin #
1
2
3
4
6
7
8
9
5,10,12,14,16
18
11
13
17
15
Name
HOLDOVER
REF 1
REF 2
FREERUN
ALARM OUT
CNT 1
CNT 2
PLL UNLOCK
GND
+5V
OUT
OPT OUT
EX REF1
EX REF 2
Description
Holdover Signal -> the unit is in holdover mode
Reference 1 Signal -> the unit is enslaved to the reference 1
Reference 2 Signal -> the unit is enslaved to the reference 2
Freerun Signal -> the unit is in the free run mode
Alarm signal
Control Input 1 -> the external input for selecting mode of the unit
Control Input 2 -> the external input for selecting mode of the unit
PLL Unlocked Signal -> the unit is unlocked
Ground
Positive Voltage Supply
Synchronized Output -> the primary output
Optional Second Output -> the secondary output, optional, user selectable
External Reference 1 Input -> the input from reference 1
External Reference 2 Input -> the input from reference 2
•
ORDERING INFORMATION
SY0003
- [Input Reference Frequencies] - [Output 1] - [Output 2] –[Output 2 type]
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
F
S
Free run
Synchronized
- For other frequencies contact the factory!
-
Example: SY0003-8-19.44-19.44-F
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
SONET MINIMUM CLOCK - SY0003
•
SPECIFICATION
General Specifications
Mechanical
Power
Environment
2” (D) x 2” (W) x 0.55” (H)
5VDC, 2W
Operating Temperature
Storage Temperature
Humidity
EMC
Voltage Controlled Crystal Oscillator
(VCXO) and Clock Oscillator
2
8kHz
HCMOS/TTL Compatible
Bellcore: GR-1244-core
2
19.44MHz
HCMOS
19.44MHz
HCMOS
<0.03UIp-p
Bellcore: GR-253-core rev. 1
Bellcore: GR-253-core rev. 1
Bellcore: GR-253-core rev. 1
Bellcore: GR-1244-core
<0.1Hz
±20ppm
±4.6ppm
<±0.05ppm
<±4.1ppm
±20ppm
1 min
Metal box, 18p dual-in-line
-20°C to 70°C
-40° to 85°C
5% to 95% non-condensing
FCC Part 15, Class B, CE Marked, UL
Internal Oscillators
Input Signals
Number of Inputs
Input reference frequency
Signal Level
Time Reference characteristics
Number of Outputs
Output 1
Output 1 Signal Level
Output 2
Output 2 Signal Level
Jitter generation
Jitter tolerance
Wander generation
Wander tolerance
Wander transfer
Filtering (Wander transfer)
Free run accuracy
Holdover stability
Initial offset
Temperature
Pull-in/Hold-in range
Holdover history
Selectable from range 4kHz to 77.76MHz
Output Signals
Selectable from range 8kHz to 38.88MHz
Free-running clock
Signal Quality
Performance
Frequency Output
Performance
•
OUTLINE DRAWING
.010
(.25)
.175
(4.45)
2.00 SQ.
(50.08 SQ.)
1.60
(40.64)
18
1
.55
(13.97)
1
SY0003
RALTRON
YYWW
.040
(1.02)
.200
(5.08)
0.147
(3.73)
.200 TYP.
(5.08 TYP.)
10
9
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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