SCAS849I June   2007  – August 2024 CDCE913 , CDCEL913

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 EEPROM Specification
    7. 5.7 Timing Requirements: CLK_IN
    8. 5.8 Timing Requirements: SDA/SCL #GUID-DE171716-D3A0-4375-A25C-58C636304087/SCAS849414
    9. 5.9 Typical Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Control Terminal Configuration
      2. 7.3.2 Default Device Configuration
      3. 7.3.3 SDA/SCL Serial Interface
      4. 7.3.4 Data Protocol
    4. 7.4 Device Functional Modes
      1. 7.4.1 SDA/SCL Hardware Interface
    5. 7.5 Programming
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Spread-Spectrum Clock (SSC)
        2. 8.2.2.2 PLL Frequency Planning
        3. 8.2.2.3 Crystal Oscillator Start-up
        4. 8.2.2.4 Frequency Adjustment with Crystal Oscillator Pulling
        5. 8.2.2.5 Unused Inputs/Outputs
        6. 8.2.2.6 Switching Between XO and VCXO Mode
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Register Maps
    1. 9.1 SDA/SCL Configuration Registers
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

8.2.2.3 Crystal Oscillator Start-up

When the CDCE913 or CDCEL913 is used as a crystal buffer, crystal oscillator start-up dominates the start-up time compared to the internal PLL lock time. The following diagram shows the oscillator start-up sequence for a 27-MHz crystal input with an 8-pF load. The start-up time for the crystal is in the order of approximately 250 µs compared to approximately 10 µs of lock time. In general, lock time is an order of magnitude less compared to the crystal start-up time.

CDCE913 CDCEL913 Crystal Oscillator Start-Up vs PLL Lock TimeFigure 8-5 Crystal Oscillator Start-Up vs PLL Lock Time