SNAS787A November   2019  – February 2020 CDCDB2000

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      CDCDB2000 System Diagram
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. Table 1. Absolute Maximum Ratings
    2. Table 2. ESD Ratings
    3. Table 3. Recommended Operating Conditions
    4. Table 4. Thermal Information
    5. Table 5. Electrical Characteristics
    6. Table 6. Timing Requirements
    7. 6.1      Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Output Enable Control
      2. 7.3.2 SMBus
        1. 7.3.2.1 SMBus Address Assignment
      3. 7.3.3 Side-Band Interface
    4. 7.4 Device Functional Modes
      1. 7.4.1 CKPWRGD_PD# Function
      2. 7.4.2 OE[12:5]# and SMBus Output Enables
    5. 7.5 Programming
      1. 7.5.1 SMBus
      2. 7.5.2 SBI
    6. 7.6 Register Maps
      1. 7.6.1 CDCDB2000 Registers
        1. 7.6.1.1  OECR1 Register (Address = 0h) [reset = 78h]
          1. Table 11. OECR1 Register Field Descriptions
        2. 7.6.1.2  OECR2 Register (Address = 1h) [reset = FFh]
          1. Table 12. OECR2 Register Field Descriptions
        3. 7.6.1.3  OECR3 Register (Address = 2h) [reset = FFh]
          1. Table 13. OECR3 Register Field Descriptions
        4. 7.6.1.4  OERDBK Register (Address = 3h) [reset = 0h]
          1. Table 14. OERDBK Register Field Descriptions
        5. 7.6.1.5  SBRDBK Register (Address = 4h) [reset = 1h]
          1. Table 15. SBRDBK Register Field Descriptions
        6. 7.6.1.6  VDRREVID Register (Address = 5h) [reset = X]
          1. Table 16. VDRREVID Register Field Descriptions
        7. 7.6.1.7  DEVID Register (Address = 6h) [reset = X]
          1. Table 17. DEVID Register Field Descriptions
        8. 7.6.1.8  BTRDCNT Register (Address = 7h) [reset = 8h]
          1. Table 18. BTRDCNT Register Field Descriptions
        9. 7.6.1.9  SBIMSK1 Register (Address = 8h) [reset = 0h]
          1. Table 19. SBIMSK1 Register Field Descriptions
        10. 7.6.1.10 SBIMSK2 Register (Address = 9h) [reset = 0h]
          1. Table 20. SBIMSK2 Register Field Descriptions
        11. 7.6.1.11 SBIMSK3 Register (Address = Ah) [reset = 0h]
          1. Table 21. SBIMSK3 Register Field Descriptions
  8. 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 Output Enable Control Method
        2. 8.2.2.2 SMBus Address
      3. 8.2.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Examples
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 TICS Pro
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

9 Power Supply Recommendations

High-performance clock buffers are sensitive to noise on the power supply, which can dramatically increase the additive jitter of the buffer. Thus, it is essential to reduce noise from the system power supply, especially when the jitter and phase noise is critical to applications.

Filter capacitors are used to eliminate the low-frequency noise from the power supply, where the bypass capacitors provide the very low impedance path for high-frequency noise and guards the power supply system against induced fluctuations. These bypass capacitors also provide instantaneous current surges as required by the device and should have low equivalent series resistance (ESR). To properly use the bypass capacitors, they must be placed very close to the power-supply terminals and laid out with short loops to minimize inductance. TI recommends to insert a ferrite bead between the board power supply and the chip power supply that isolates the high-frequency switching noises generated by the clock buffer. These beads prevent the switching noise from leaking into the board supply. It is imperative to choose an appropriate ferrite bead with very low DC resistance to provide adequate isolation between the board supply and the chip supply, as well as to maintain a voltage at the supply terminals that is greater than the minimum voltage required for proper operation.

shows the recommended power supply filtering and decoupling method.

CDCDB2000 PS_filter_SNAS787.gifFigure 11. Power Supply Decoupling