SNAS784B March   2019  – August 2019 LMK00804B-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  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. Power Supply Characteristics
    6. Table 6. LVCMOS / LVTTL DC Electrical Characteristics
    7. Table 7. Differential Input DC Electrical Characteristics
    8. Table 8. Switching Characteristics
    9. Table 9. Pin Characteristics
    10. 6.1      Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Clock Enable Timing
    4. 8.4 Device Functional Modes
  9. 9 Applications and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Output Clock Interface Circuit
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curve
          1. 9.2.1.3.1 System-Level Phase Noise and Additive Jitter Measurement
      2. 9.2.2 Input Detail
      3. 9.2.3 Input Clock Interface Circuits
    3. 9.3 Do's and Don'ts
      1. 9.3.1 Power Dissipation Calculations
      2. 9.3.2 Thermal Management
      3. 9.3.3 Recommendations for Unused Input and Output Pins
      4. 9.3.4 Input Slew Rate Considerations
  10. 10Power Supply Recommendations
    1. 10.1 Power Supply Considerations
      1. 10.1.1 Power-Supply Filtering
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Ground Planes
      2. 11.1.2 Power Supply Pins
      3. 11.1.3 Differential Input Termination
      4. 11.1.4 LVCMOS Input Termination
      5. 11.1.5 Output Termination
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

10.1.1 Power-Supply Filtering

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 jitter or phase noise is critical to applications.

The use of bypass capacitors eliminates the low-frequency noise from power supply, because they can provide a very low-impedance path for high-frequency noise and guard the power-supply system against induced fluctuations. The bypass capacitors also provide instantaneous current surges as required by the device, and should have low ESR. To use the bypass capacitors properly, place them close to the power supply terminals and lay out traces with short loops to minimize inductance. TI recommends that the engineer add as many high-frequency (for example, 0.1-µF) bypass capacitors as there are supply terminals in the package. TI recommends that the engineer insert a ferrite bead between the board power supply and the chip power supply to isolate the high-frequency switching noises generated by the clock driver. This would prevent leakage into the board supply. It is important to choose an appropriate ferrite bead with low DC resistance, because the bead must provide adequate isolation between the board supply and the chip supply. It is also important to maintain a voltage at the supply terminals that is greater than the minimum voltage required for proper operation.

LMK00804B-Q1 0016.gifFigure 15. Power-Supply Decoupling