SNAS512K September   2011  – October 2025 LMK00301

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison
  6. 5 Pin Configuration and Functions
  7. 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 Typical Characteristics
  8. 7 Parameter Measurement Information
    1. 7.1 Differential Voltage Measurement Terminology
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 VCC and VCCO Power Supplies
    4. 8.4 Device Functional Modes
      1. 8.4.1 Clock Inputs
      2. 8.4.2 Clock Outputs
        1. 8.4.2.1 Reference Output
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
        1. 9.2.1.1 Driving the Clock Inputs
        2. 9.2.1.2 Crystal Interface
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Termination and Use of Clock Drivers
          1. 9.2.2.1.1 Termination for DC Coupled Differential Operation
          2. 9.2.2.1.2 Termination for AC Coupled Differential Operation
          3. 9.2.2.1.3 Termination for Single-Ended Operation
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
      1. 9.3.1 Power Supply Sequencing
      2. 9.3.2 Current Consumption and Power Dissipation Calculations
        1. 9.3.2.1 Power Dissipation Example #1: Separate VCC and VCCO Supplies with Unused Outputs
        2. 9.3.2.2 Power Dissipation Example #2: Worst-Case Dissipation
      3. 9.3.3 Power Supply Bypassing
        1. 9.3.3.1 Power Supply Ripple Rejection
      4. 9.3.4 Thermal Management
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  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

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information
9.2.2.1.3 Termination for Single-Ended Operation

A balun can be used with either LVDS or LVPECL drivers to convert the balanced, differential signal into an unbalanced, single-ended signal.

Use an LVPECL driver as one or two separate 800mV p-p signals. When DC coupling one of the LMK00301 LVPECL driver of a CLKoutX/CLKoutX* pair, be sure to properly terminate the unused driver. When DC coupling on of the LMK00301 LVPECL drivers, the termination must be 50Ω to Vcco - 2V as shown in Figure 9-13. The Thevenin equivalent circuit is also a valid termination as shown in Figure 9-14 for Vcco = 3.3V.

LMK00301 Single-Ended LVPECL Operation, DC CouplingFigure 9-13 Single-Ended LVPECL Operation, DC Coupling
LMK00301 Single-Ended LVPECL Operation, DC Coupling, Thevenin EquivalentFigure 9-14 Single-Ended LVPECL Operation, DC Coupling, Thevenin Equivalent

When AC coupling an LVPECL driver use a 160Ω emitter resistor (or 91Ω for Vcco = 2.5V) to provide a DC path to ground and provide a 50Ω termination with the proper DC bias level for the receiver. The typical DC bias voltage for LVPECL receivers is 2V. If the companion driver is not used, the companion driver must be terminated with either a proper AC or DC termination. This latter example of AC coupling a single-ended LVPECL signal can be used to measure single-ended LVPECL performance using a spectrum analyzer or phase noise analyzer. When using most RF test equipment no DC bias point (0VDC) is required for safe and proper operation. The internal 50Ω termination the test equipment correctly terminates the LVPECL driver being measured as shown in Figure 9-15. When using only one LVPECL driver of a CLKoutX/CLKoutX* pair, be sure to properly terminated the unused driver.

LMK00301 Single-Ended LVPECL Operation, AC CouplingFigure 9-15 Single-Ended LVPECL Operation, AC Coupling