SGLS390G July   2009  – November 2015 CDCM7005-SP

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements
    7. 7.7 Typical Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Automatic/Manual Reference Clock Switching
      2. 9.3.2 PLL Lock for Analog and Digital Detect
        1. 9.3.2.1 PLL Lock/Out-of-Lock Definition
        2. 9.3.2.2 Digital vs Analog Lock
      3. 9.3.3 Differential LVPECL Outputs and Single-Ended LVCMOS Outputs
      4. 9.3.4 Frequency Hold-Over Mode
      5. 9.3.5 Charge Pump Preset to VCC_CP / 2
      6. 9.3.6 Charge Pump Current Direction
    4. 9.4 Device Functional Modes
    5. 9.5 Programming
      1. 9.5.1 SPI Control Interface
      2. 9.5.2 Functional Description of the Logic
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Clock Generation for Interpolating DACs With the CDCM7005-SP
        1. 10.1.1.1 AC-Coupled Interface to ADC/DAC
      2. 10.1.2 Phase Noise Performance
        1. 10.1.2.1 In-Band Noise Performance
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
      3. 10.2.3 Application Curve
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Examples
  13. 13Device and Documentation Support
    1. 13.1 Community Resources
    2. 13.2 Trademarks
    3. 13.3 Electrostatic Discharge Caution
    4. 13.4 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

12 Layout

12.1 Layout Guidelines

High frequency input signals should be routed through shortest paths possible.

Continuous ground plane should be spread under the high signal routes to minimize the current loops.

Supply bypass caps should be placed as close to the device. Do not have vias between the bypass caps and the device.

Keep differential traces together to keep noise injection as a common-mode signal.

Route differential traces around obstacles together, do not separate. Keep traces together with exact same length to keep delays equal.

Top layer routing of clock signals has less propagation delay, immunity to noise could be enhanced by having ground planes on the same layer away by 2x trace width. The magnetic radiation is also enhanced by this ground layer. Ensure multiple vias are utilized and placed near signal traces on the ground plane.

12.2 Layout Examples

CDCM7005-SP Layout_ex_QFN.png Figure 29. Layout Example, Quad Flat Pack Package