SNAS522K September   2011  – December 2023 LMK03806

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements
    7. 5.7 Typical Characteristics
  7. 6 Parameter Measurement Information
    1. 6.1 Differential Voltage Measurement Terminology
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagrams
    3. 7.3 Features Description
      1. 7.3.1 Serial MICROWIRE Timing Diagram and Terminology
      2. 7.3.2 Crystal Support With Buffered Outputs
      3. 7.3.3 Integrated Loop Filter Poles
      4. 7.3.4 Integrated VCO
      5. 7.3.5 Clock Distribution
        1. 7.3.5.1 CLKout DIvider
        2. 7.3.5.2 Programmable Output Type
        3. 7.3.5.3 Clock Output Synchronization
      6. 7.3.6 Default Start-Up Clocks
    4. 7.4 Device Functional Modes
    5. 7.5 Programming
      1. 7.5.1 General Information
        1. 7.5.1.1 Special Programming Case for R0 to R5 for CLKoutX_Y_DIV > 25
        2. 7.5.1.2 Recommended Initial Programming Sequence
        3. 7.5.1.3 READBACK
          1. 7.5.1.3.1 Readback Example
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Crystal Interface
      2. 8.1.2 Driving OSCin Pins With a Single-Ended Source
      3. 8.1.3 Driving OSCin Pins With a Differential Source
      4. 8.1.4 Frequency Planning With the LMK03806
      5. 8.1.5 Configuring the PLL
        1. 8.1.5.1 Example PLL Configuration
      6. 8.1.6 Digital Lock Detect
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Device Selection
          1. 8.2.2.1.1 Clock Architect
          2. 8.2.2.1.2 Clock Design Tool
          3. 8.2.2.1.3 Calculation Using LCM
        2. 8.2.2.2 Device Configuration
        3. 8.2.2.3 PLL Loop Filter Design
          1. 8.2.2.3.1 Example Loop Filter Design
        4. 8.2.2.4 Other Device Specific Configuration
          1. 8.2.2.4.1 Digital Lock Detect
        5. 8.2.2.5 Device Programming
      3. 8.2.3 Application Curves
    3. 8.3 System Examples
      1. 8.3.1 System Level Diagram
    4. 8.4 Best Design Practices
      1. 8.4.1 LVCMOS Complementary vs. Non-Complementary Operation
      2. 8.4.2 LVPECL Outputs
      3. 8.4.3 Sharing MICROWIRE (SPI) Lines
      4. 8.4.4 SYNC Pin
      5. 8.4.5 CLKout Vcc Pins
    5. 8.5 Power Supply Recommendations
      1. 8.5.1 Current Consumption and Power Dissipation Calculations
    6. 8.6 Layout
      1. 8.6.1 Layout Guidelines
      2. 8.6.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Development Support
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  11. 10Register Maps
    1. 10.1  Default Device Register Settings After Power On Reset
    2. 10.2  Register R0 TO R5
      1. 10.2.1 CLKoutX_Y_PD, Powerdown CLKoutX_Y Output Path
      2. 10.2.2 RESET
      3. 10.2.3 POWERDOWN
      4. 10.2.4 CLKoutX_Y_DIV, Clock Output Divide
    3. 10.3  Registers R6 TO R8
      1. 10.3.1 CLKoutX_TYPE
    4. 10.4  REGISTER R9
    5. 10.5  REGISTER R10
      1. 10.5.1 OSCout1_TYPE, LVPECL Output Amplitude Control
      2. 10.5.2 OSCout0_TYPE
      3. 10.5.3 EN_OSCoutX, OSCout Output Enable
      4. 10.5.4 OSCoutX_MUX, Clock Output Mux
      5. 10.5.5 OSCout_DIV, Oscillator Output Divide
    6. 10.6  REGISTER R11
      1. 10.6.1 NO_SYNC_CLKoutX_Y
      2. 10.6.2 SYNC_POL_INV
      3. 10.6.3 SYNC_TYPE
      4. 10.6.4 EN_PLL_XTAL
    7. 10.7  REGISTER R12
      1. 10.7.1 LD_MUX
      2. 10.7.2 LD_TYPE
      3. 10.7.3 SYNC_PLL_DLD
    8. 10.8  REGISTER R13
      1. 10.8.1 READBACK_TYPE
      2. 10.8.2 GPout0
    9. 10.9  REGISTER 14
      1. 10.9.1 GPout1
    10. 10.10 REGISTER 16
    11. 10.11 REGISTER 24
      1. 10.11.1 PLL_C4_LF, PLL Integrated Loop Filter Component
      2. 10.11.2 PLL_C3_LF, PLL Integrated Loop Filter Component
      3. 10.11.3 PLL_R4_LF, PLL Integrated Loop Filter Component
      4. 10.11.4 PLL_R3_LF, PLL Integrated Loop Filter Component
    12. 10.12 REGISTER 26
      1. 10.12.1 EN_PLL_REF_2X, PLL Reference Frequency Doubler
      2. 10.12.2 PLL_CP_GAIN, PLL Charge Pump Current
      3. 10.12.3 PLL_DLD_CNT
    13. 10.13 REGISTER 28
      1. 10.13.1 PLL_R, PLL R Divider
    14. 10.14 REGISTER 29
      1. 10.14.1 OSCin_FREQ, PLL Oscillator Input Frequency Register
      2. 10.14.2 PLL_N_CAL, PLL N Calibration Divider
    15. 10.15 REGISTER 30
      1. 10.15.1 PLL_P, PLL N Prescaler Divider
      2. 10.15.2 PLL_N, PLL N Divider
    16. 10.16 REGISTER 31
      1. 10.16.1 READBACK_ADDR
      2. 10.16.2 uWire_LOCK
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

8.1.4 Frequency Planning With the LMK03806

Calculating the value of the output dividers is simple due to the architecture of the LMK03806. That is, the clock output dividers allow for even and odd output divide values from 2 to 1045. The procedure for determining the PLL and clock output divider values for a set of clock output frequencies is straightforward.

  1. Calculate the least common multiple (LCM) of the clock output frequencies.
  2. Determine which VCO frequency will support the target clock output frequencies given the LCM.
  3. Determine the clock output divide values based on VCO frequency.
  4. Determine the PLL divider values – VCO_DIV, PLL_P, PLL_N, and PLL_R – to allow the VCO frequency to lock to the OSCin frequency. For best in-band PLL noise, try to maximize the PLL phase detector frequency by using the smallest PLL divider values and enabling the PLL doubler.

For example, given the following target output frequencies: 156.25 MHz, 125 MHz, 100 MHz, and 25 MHz with a OSCin frequency of 20 MHz:

  1. Determine the LCM of the three frequencies. LCM(156.25, 125, 100, 25) = 2500 MHz. The LCM frequency is the lowest frequency for which all of the target output frequencies are integer divisors of the LCM. Note: if there is one frequency which causes the LCM to be very large, greater than 2.6 GHz for example, determine if there is a single frequency requirement which causes this. It may be possible to select the crystal frequency to satisfy this frequency requirement through OSCout or CLKout6/7/8/9 driven by OSCin. In this way it is possible to get non-integer related frequencies at the outputs.
  2. Multiply the LCM frequency by an integer value that causes the product (LCM × X) to fall into the valid VCO frequency range from 2370 to 2600 MHz. In this case, the LCM frequency of 2500 MHz is already within the VCO frequency.
  3. Continuing the example by using a VCO frequency of 2500 MHz, the CLKout dividers can be calculated by simply dividing the VCO frequency by the output frequency. To output 156.25 MHz, 125 MHz, 100 MHz, and 25 MHz, the output dividers will be 16, 20, 25, and 100, respectively.
    1. 2500 MHz / 156.25 MHz = 16
    2. 2500 MHz / 125 MHz = 20
    3. 2500 MHz / 100 MHz = 25
    4. 2500 MHz / 25 MHz = 100
  4. The PLL must be locked to its input reference. Refer to Configuring the PLL for more information on this topic. By programming the clock output dividers and the PLL dividers, the VCO can be locked to 2500 MHz and the clock outputs dividers can each divide-down the VCO frequency to the achieve the target output frequencies.

Refer to Application Note AN-1865, Frequency Synthesis and Planning for PLL Architectures (SNAA061) for more information on this topic and LCM calculations.