SNAS573D January   2012  – September 2021 LMK01801

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison
    1. 5.1 Functional Configurations
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 Recommended Operating Conditions
    3. 7.3 Thermal Information
    4. 7.4 Electrical Characteristics
    5. 7.5 Serial MICROWIRE Timing Diagram
    6. 7.6 Typical Characteristics
  8. 8 Parameter Measurement Information
    1. 8.1 Differential Voltage Measurement Terminology
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1  High-Speed Clock Inputs (CLKin0/CLKin0* and CLKin1/CLKin1*)
      2. 9.3.2  Clock Distribution
      3. 9.3.3  Small Divider (1 to 8)
      4. 9.3.4  Large Divider (1 to 1045)
      5. 9.3.5  CLKout Analog Delay
      6. 9.3.6  CLKout0 to CLKout11 Digital Delay
      7. 9.3.7  CLKout12 and CLKout13 Digital Delay
      8. 9.3.8  Programmable Outputs
      9. 9.3.9  Clock Output Synchronization
      10. 9.3.10 Default Clock Outputs
    4. 9.4 Device Functional Modes
      1. 9.4.1 Programmable Mode
      2. 9.4.2 Pin Control Mode
      3. 9.4.3 Inputs / Outputs
        1. 9.4.3.1 CLKin0 and CLKin1
      4. 9.4.4 Input and Output Dividers
      5. 9.4.5 Fixed Digital Delay
        1. 9.4.5.1 Fixed Digital Delay - Example
      6. 9.4.6 Clock Output Synchronization (SYNC)
        1. 9.4.6.1 Dynamically Programming Digital Delay
          1. 9.4.6.1.1 Relative Dynamic Digital Delay
          2. 9.4.6.1.2 Relative Dynamic Digital Delay - Example
    5. 9.5 Programming
      1. 9.5.1 Recommended Programming Sequence
        1. 9.5.1.1 Overview
    6. 9.6 Register Map
      1. 9.6.1 Default Device Register Settings After Power On/Reset
      2. 9.6.2 Register R0
        1. 9.6.2.1 RESET
        2. 9.6.2.2 POWERDOWN
        3. 9.6.2.3 CLKoutX_Y_PD
          1. 9.6.2.3.1 CLKinX_BUF_TYPE
          2. 9.6.2.3.2 CLKinX_DIV
          3. 9.6.2.3.3 CLKinX_MUX
      3. 9.6.3 Register R1 and R2
        1. 9.6.3.1 CLKoutX_TYPE
      4. 9.6.4 Register R3
        1. 9.6.4.1 CLKout12_13_ADLY
        2. 9.6.4.2 CLKout12_13_HS, Digital Delay Half Shift
        3. 9.6.4.3 SYNC1_QUAL
        4. 9.6.4.4 SYNCX_POL_INV
        5. 9.6.4.5 NO_SYNC_CLKoutX_Y
        6. 9.6.4.6 CLKoutX_Y_OFFSET_PD
        7. 9.6.4.7 SYNCX_FAST
        8. 9.6.4.8 SYNCX_AUTO
      5. 9.6.5 Register R4
        1. 9.6.5.1 CLKout12_13_DDLY, Clock Channel Digital Delay
      6. 9.6.6 Register R5
        1. 9.6.6.1 CLKout12_ADLY_SEL[13], CLKout13_ADLY_SEL[14], Select Analog Delay
        2. 9.6.6.2 CLKoutX_Y_DIV Clock Output Divide
      7. 9.6.7 Register 15
        1. 9.6.7.1 uWireLock
  10. 10Application and Implementation
    1. 10.1 Typical Application
      1. 10.1.1 Detailed Design Procedure
        1. 10.1.1.1 Driving CLKin Inputs
          1. 10.1.1.1.1 Driving CLKin Pins With a Differential Source
          2. 10.1.1.1.2 Driving CLKin Pins With a Single-Ended Source
        2. 10.1.1.2 Termination and Use of Clock Output (Drivers)
          1. 10.1.1.2.1 Termination for DC-Coupled Differential Operation
          2. 10.1.1.2.2 Termination for AC-Coupled Differential Operation
          3. 10.1.1.2.3 Termination for Single-Ended Operation
  11. 11Power Supply Recommendations
    1. 11.1 Current Consumption
  12. 12Layout
    1. 12.1 Layout Guidelines
      1. 12.1.1 Pin Connection Recommendations
        1. 12.1.1.1 Vcc Pins and Decoupling
        2. 12.1.1.2 Unused clock outputs
        3. 12.1.1.3 Unused clock inputs
        4. 12.1.1.4 Unused GPIO (CLKoutTYPE_X)
        5. 12.1.1.5 Bias
        6. 12.1.1.6 In MICROWIRE Mode
    2. 12.2 Thermal Management
  13. 13Device and Documentation Support
    1. 13.1 Documentation Support
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Support Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information
10.1.1.2.2 Termination for AC-Coupled Differential Operation

AC coupling allows for shifting the DC bias level (common-mode voltage) when driving different receiver standards. AC coupling prevents the driver from providing a DC bias voltage at the receiver, therefore it is important to ensure the receiver is biased to its ideal DC level.

When driving non-biased LVDS receivers with an LVDS driver, the signal may be AC coupled by adding DC blocking capacitors, however the proper DC bias point needs to be established at the receiver. One way to do this is with the termination circuitry in Figure 10-9.

GUID-608991F7-BAEB-4A86-B9B4-F21F948A17B9-low.gifFigure 10-9 Differential LVDS Operation, AC Coupling, External Biasing at the Receiver

Some LVDS receivers may have internal biasing on the inputs. In this case, the circuit shown in is modified by replacing the 50-Ω terminations to Vbias with a single 100-Ω resistor across the input pins of the receiver, as shown in Figure 10-10. When using AC coupling with LVDS outputs, there may be a start-up delay observed in the clock output due to capacitor charging. The previous figures employ a 0.1-μF capacitor. This value may need to be adjusted to meet the start-up requirements for a particular application.

GUID-9DBAD384-0387-4A35-96CA-F31C6A7673C5-low.gifFigure 10-10 LVDS Termination for a Self-Biased Receiver

LVPECL drivers require a DC path to ground. When AC coupling an LVPECL signal use 120-Ω to 240-Ω emitter resistors close to the LVPECL driver to provide a DC path to ground as shown in Figure 10-11. For proper receiver operation, the signal should be biased to the DC bias level (common-mode voltage) specified by the receiver. The typical DC bias voltage for LVPECL receivers is 2 V.

A typical application is shown in Figure 10-11, where Rem = 120 Ω to 240 Ω. Refer to the receiver input recommendations to determine if the proper value of CA’s, if needed.

GUID-60B3074F-124B-4CD3-B66B-1099AE3424FD-low.gifFigure 10-11 Differential LVPECL Operation, AC Coupling, External Biasing at the Receiver, Rem = 120 Ω to 240 Ω