SYNCHRONOUS EQUIPMENT OCXO BASED STRATUM 3 CLOCK UNIT WITH A 2 ND FREE-RUN CLOCK OUTPUT – SY01-S3F SY01-S3F Date: April 20 , 2002 • INTRODUCTION The SY01-S3F 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 SY01-S3F is an excellent OCXO based synchronization solution for Stratum 3 applications with an additional +/-4.6PPM free-run TCXO. • FEATURES A Hardware/Software synchronization solution for timing, jitter and wander concerns in a single module. Complies with ITU-T Recommendations G.813 and ETSI-ETS 300 462-4 and Bellcore GR-1244-CORE for Stratum 3 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. Provides a secondary free-run output within +/-4.6PPM 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. Alarm and status signal. Host interface and JTAG port. Small dimensions of 1.80X1.80X 0.65 inch (open pkg) • APPLICATION The SY01-S3F performs clock regeneration as a Synchronous Equipment Clock (SEC), or STRATUM 3 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 SY01-S3F 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 SY01-S3F with a low cost GPS receiver and locking it to the GPS 1 pps output signal. RALTRON ELECTRONICS CORP. § 10651 N.W.19th St § Florida 33172 § U.S.A. Tel: 305 593-6033 § Fax: 305-594-3973 § e-mail: [email protected] § Internet: http:/www.raltron.com SYNCHRONOUS EQUIPMENT OCXO BASED STRATUM 3 CLOCK UNIT WITH A 2 ND FREE-RUN CLOCK OUTPUT – SY01-S3F SCI J-TAG Temp. Sensor DAC 1 DSP OCXO CPLD EX REF1 EX REF2 MUX PD1 FLASH RAM TCXO ÷÷ N CNT1 CNT2 CONTROL LOGIC ALARM OUT PLL UNLOCK OUT HOLDOVER REF 1 REF 2 PD2 OUTPUT FREQUENCY CONVERTERS OPT OUT FREE RUN Figure 1. - The functional block diagram of SY01-S3F • DESCRIPTION The SY01-S3F 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 an OCXO as on-board oscillator, shown in figure 1 as the shaded boxes. The OCXO is driven by a digital-to-analog converter (DAC1) and provides the accurate and stable signal under all conditions. 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 ±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 SY01-S3F 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 SY01-S3F 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 RALTRON ELECTRONICS CORP. § 10651 N.W.19th St § Florida 33172 § U.S.A. Tel: 305 593-6033 § Fax: 305-594-3973 § e-mail: [email protected] § Internet: http:/www.raltron.com SYNCHRONOUS EQUIPMENT OCXO BASED STRATUM 3 CLOCK UNIT WITH A 2 ND FREE-RUN CLOCK OUTPUT – SY01-S3F the clock is mounted. The SY01-S3F 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. 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 SY01-S3F 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 SY01-S3F 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 SY0001D module provides two output signals OUT and OPT OUT. The first output (OUT) is synchronized and is generated by the internal Stratum 3 OCXO oscillator and scaled by the output frequency converters. The second output (OPT OUT) is not synchronized and comes from free-running +/-20PPM overall stability TCXO (SMC level). The performance of the module significantly depends on the internal oscillators and special care was taken to define its specifications. The frequency of the oscillator is specified according to the network application where the SY0001D will be used. • The SY01 Operation mode By changing the control inputs the user can change the state of the SY01 according to the state diagram. The SY01 offers two ways to manage state machine: J1 jumper Open Closed State diagram control Manual Automatic The behavior of the Manual and Automatic controls are shown on the figures 2 and 3 with an explanation for each transition. In the Automatic control the SY01 can be automatically switched to the reference (if available) regardless of status of the control inputs. In Manual control the unit waits for control inputs to be changed. In both modes the unit will go to the REFERENCE EVALUATION if the previously lost reference is required. • Control Two controls are available for the user to control the operation of the SY01. The two external inputs CNT1 and CNT2 provide this feature. Below, the truth table shows behavior of the SY01 module according to the control inputs states. RALTRON ELECTRONICS CORP. § 10651 N.W.19th St § Florida 33172 § U.S.A. Tel: 305 593-6033 § Fax: 305-594-3973 § e-mail: [email protected] § Internet: http:/www.raltron.com SYNCHRONOUS EQUIPMENT OCXO BASED STRATUM 3 CLOCK UNIT WITH A 2 ND FREE-RUN CLOCK OUTPUT – SY01-S3F CNT2 0 0 1 1 • CNT1 0 1 0 1 MODE OF OPERATION Free-run Locked to REF1 Locked to REF2 Holdover SPECIFICATIONS General Specifications Mechanical Input Signals Power Supply Warm Up Current Supply Steady State 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 Output Signal Signal Quality Performance 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 0.65” (H) 5VDC 900mA max 400mA max. -20°C to 70°C -40° to 85°C 5% to 95% non-condensing OCXO 2 8kHz to 77.76MHz HCMOS/TTL Compatible Other ranges available on request User selectable Bellcore: GR-1244-core 3.2.1.R3-1 2 8kHz to 77.76MHz 8kHz to 77.76MHz LVCMOS/HCMOS Jitter Tolerance Phase Transient Tolerance Wander Generation Wander Tolerance Jitter Generation and Transfer Wander Transfer Frequency Output Performance Hermetically Sealed Metal box Metal Box Module on PCB Regulated User define (Startum 3 Level) User define (Free run SMC clock) Depend of the frequency output Bellcore: GR-1244-core 4.2 ITU-T: G.813 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 Free run accuracy ±4.6ppm Holdover frequency stability ±3.7x10-7 for 24hours Initial Offset ±50x10-9 Bellcore: GR-1244-core 5.2 ITU-T: G.812 Temperature ±0.28x10-6 ±1.0x10-6 Over operating temperature range Drift ±40x10-9 DPLL bandwidth Lock Time Lock accuracy 0.1Hz <30sec ±1x10-11 Bellcore: GR-1244-core 5.2 ITU-T: G.812 Or adjustable GR-1244-core 3.7 RALTRON ELECTRONICS CORP. § 10651 N.W.19th St § Florida 33172 § U.S.A. Tel: 305 593-6033 § Fax: 305-594-3973 § e-mail: [email protected] § Internet: http:/www.raltron.com SYNCHRONOUS EQUIPMENT OCXO BASED STRATUM 3 CLOCK UNIT WITH A 2 ND FREE-RUN CLOCK OUTPUT – SY01-S3F • PIN ASSIGNMENT On the picture below it is shown the pin-out for the SY01-S3F. 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 18 1 HOLDOVER EX REF1 17 2 REF 1 GND 16 3 REF2 EX REF 2 15 4 FREERUN GND 14 5 OPT OUT 13 6 GND 12 7 OUT 11 8 GND 10 9 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 Name HOLDOVER REF 1 REF 2 FREERUN 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 ALARM OUT condition 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 OUT range see 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! RALTRON ELECTRONICS CORP. § 10651 N.W.19th St § Florida 33172 § U.S.A. Tel: 305 593-6033 § Fax: 305-594-3973 § e-mail: [email protected] § Internet: http:/www.raltron.com SYNCHRONOUS EQUIPMENT OCXO BASED STRATUM 3 CLOCK UNIT WITH A 2 ND FREE-RUN CLOCK OUTPUT – SY01-S3F • MECHANICAL DIMENSIONS Hermetically Sealed option PCB option • Order Information Please contact Factory for assignined P/N RALTRON ELECTRONICS CORP. § 10651 N.W.19th St § Florida 33172 § U.S.A. Tel: 305 593-6033 § Fax: 305-594-3973 § e-mail: [email protected] § Internet: http:/www.raltron.com