JAJSHH9H May   2008  – May 2019 DS90LV028AQ-Q1


  1. 特長
  2. アプリケーション
  3. 概要
    1.     Device Images
      1.      機能図
  4. 改訂履歴
  5. Pin Configuration and Functions
    1.     Pin Descriptions
  6. Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Switching Characteristics
    7. 6.7 Typical Performance Curves
  7. Parameter Measurement Information
  8. Detailed Description
    1. 8.1 Functional Block Diagram
    2. 8.2 Device Functional Modes
  9. Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Detailed Design Procedure
        1. Power Decoupling Recommendations
        2. Termination
        3. Input Failsafe Biasing
        4. Probing LVDS Transmission Lines
        5. Cables and Connectors, General Comments
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Differential Traces
      2. 10.1.2 PC Board Considerations
  11. 11デバイスおよびドキュメントのサポート
    1. 11.1 デバイス・サポート
    2. 11.2 コミュニティ・リソース
    3. 11.3 商標
    4. 11.4 静電気放電に関する注意事項
    5. 11.5 Glossary
  12. 12メカニカル、パッケージ、および注文情報



Differential Traces

Use controlled impedance traces which match the differential impedance of your transmission medium (ie. cable) and termination resistor. Run the differential pair trace lines as close together as possible as soon as they leave the IC (stubs should be < 10mm long). This will help eliminate reflections and ensure noise is coupled as common-mode. In fact, we have seen that differential signals which are 1mm apart radiate far less noise than traces 3mm apart since magnetic field cancellation is much better with the closer traces. In addition, noise induced on the differential lines is much more likely to appear as common-mode which is rejected by the receiver.

Match electrical lengths between traces to reduce skew. Skew between the signals of a pair means a phase difference between signals which destroys the magnetic field cancellation benefits of differential signals and EMI will result! (Note that the velocity of propagation, v = c/E r where c (the speed of light) = 0.2997 mm/ps or 0.0118 in/ps). Do not rely solely on the autoroute function for differential traces. Carefully review dimensions to match differential impedance and provide isolation for the differential lines. Minimize the number of vias and other discontinuities on the line.

Avoid 90° turns (these cause impedance discontinuities). Use arcs or 45° bevels.

Within a pair of traces, the distance between the two traces should be minimized to maintain common-mode rejection of the receivers. On the printed circuit board, this distance should remain constant to avoid discontinuities in differential impedance. Minor violations at connection points are allowable.