データシートサーチシステム |
|
SM3-025.92M データシート(PDF) 2 Page - Connor-Winfield Corporation |
|
SM3-025.92M データシート(HTML) 2 Page - Connor-Winfield Corporation |
2 / 36 page Data Sheet #: TM052 Page 2 of 36 Rev: 03 Date: 11/07/08 © Copyright 2008 The Connor-Winfield Corp. All Rights Reserved Specifications subject to change without notice General Description The SM3 timing module provides a clock output that meets or exceeds Stratum 3 specifications given in GR-1244-CORE (Issue 2), GR-253-CORE (Issue 3), ITU-T G.812 (Type 3) and ITU-T G813 (Option 2). The SM3 features four reference inputs that will auto-detect the following reference frequencies: 8 kHz, 1.544 MHz, 2.048 MHz, 12.96 MHz, 19.44 MHz, 25.92 MHz, 38.88 MHz, 51.84 MHz and 77.76 MHz. The SM3 timing module can be configured during production to produce an output up to 77.76 MHz. This output is derived from an onboard VCXO and must be specified when ordering. The BITS output selectable for either 1.544 or 2.048 MHz. The master/ slave output is 8KHz. The user communicates with the SM3 module through a SPI port. The user controls the SM3 operation by writing to the appropriate registers . The user can also enable or disable SPI operation through a SPI_Enable pin. The SM3 offers a wide range of options for the system designer. The bandwidth is SPI Por t-selectable from 0.025 Hz to 1.6 Hz. 0.098 Hz is the recommended operational bandwidth for SONET Minimum Clock and most Stratum 3 applications. The 8 kHz out- put has an adjustable pulse width. The pull-in range is also adjustable to establish the desired reference frequency rejection lim- its. A Free Run frequency calibration value can be written to the module to provide a high degree of accuracy in the free run mode. The reference frequency for any given reference input is automatically detected. A wealth of status information is available through the SPI Port registers. The user also has a choice between autonomous or full manual control operation. In manual mode, the user controls the module operating modes Free Run, Hold Over or locked to a specific reference in nor- mal mode. If the chosen reference is unavailable or disqualified the module automatically enters Hold Over. In autonomous control mode, operational mode selection occurs automatically based on reference priority and qualification status. When the active reference becomes disqualified, the module will switch to another qualified reference. If none is available, it will switch to Holdover. In the revertive mode the module will seek to acquire the highest priority qualified reference. In the non- revertive mode the module will not return to the previous reference even after it is re-qualified unless there are no other qualified references. Switching between references is hitless. Likewise, the output frequency slew rate is minimized during any change of operating mode, including entry into and return from Free Run or Hold Over to protect traffic from transient-induced bit errors. Reference Status information and the operating mode information is accessed through status registers. The module will set the Interrupt pin (SPI_INT) low to indicate a status change. An Alarm pin is used to indicate failure of the active reference status. Free Run operation guarantees an output within 4.6ppm of nominal frequency and Holdover operation guarantees the output frequency will not change by more than 0.37ppm during the first 24 hours. Frequency accuracy is based on a TCXO for its small size, low power consumption and outstanding performance over all environmental conditions. The module operates on 3.3V ± 5% with a typical power draw of less than 500 milliwatts. The module operates over the 0° to 70°C commercial temperature range. Functional Block Diagram Figure 1 Reference Input Monitor Control Mode Reference Selection DPLL APLL Reference Priority, Revertivity and Mask Table Bus Interface EEPROM DAC OCXO VCXO TRST TCK TDO TDI TMS M/S REF REF 1 - 4 RESET MASTER SELECT T1/E1 SPI_ENBL SPI_CLK SPI_IN SPI_OUT SPI_INT 4 OUTPUT1 M/S_OUT BITS_CLK LOS LOL HOLD_GOOD |
同様の部品番号 - SM3-025.92M |
|
同様の説明 - SM3-025.92M |
|
|
リンク URL |
プライバシーポリシー |
ALLDATASHEET.JP |
ALLDATASHEETはお客様のビジネスに役立ちますか? [ DONATE ] |
Alldatasheetは | 広告 | お問い合わせ | プライバシーポリシー | リンク交換 | メーカーリスト All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |