SNAS800B July   2021  – February 2024 LMX1204

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 Timing Diagram
    8. 5.8 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
      1. 6.1.1 Range of Dividers and Multiplier
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Power On Reset
      2. 6.3.2 Temperature Sensor
      3. 6.3.3 Clock Outputs
        1. 6.3.3.1 Clock Output Buffers
        2. 6.3.3.2 Clock MUX
        3. 6.3.3.3 Clock Divider
        4. 6.3.3.4 Clock Multiplier and Filter Modes
          1. 6.3.3.4.1 General Information About the Clock Multiplier
          2. 6.3.3.4.2 State Machine Clock for the Clock Multiplier
            1. 6.3.3.4.2.1 State Machine Clock
          3. 6.3.3.4.3 Calibration for the Clock Multiplier
          4. 6.3.3.4.4 Using the x1 Clock Multiplier as a Filter
          5. 6.3.3.4.5 Lock Detect for the Clock Multiplier
      4. 6.3.4 Device Functional Modes Configurations
      5. 6.3.5 LOGICLK Output
        1. 6.3.5.1 LOGICLK Output Format
        2. 6.3.5.2 LOGICLK_DIV_PRE and LOGICLK_DIV Dividers
      6. 6.3.6 SYSREF
        1. 6.3.6.1 SYSREF Output Buffers
          1. 6.3.6.1.1 SYSREF Output Buffers for Main Clocks (SYSREFOUT)
          2. 6.3.6.1.2 SYSREF Output Buffer for LOGICLK
        2. 6.3.6.2 SYSREF Frequency and Delay Generation
        3. 6.3.6.3 SYSREFREQ pins and SYSREFREQ_SPI Field
          1. 6.3.6.3.1 SYSREFREQ Pins Common-Mode Voltage
          2. 6.3.6.3.2 SYSREFREQ Windowing Feature
            1. 6.3.6.3.2.1 General Procedure Flowchart for SYSREF Windowing Operation
            2. 6.3.6.3.2.2 SYSREFREQ Repeater Mode With Delay Gen (Retime)
      7. 6.3.7 SYNC Feature
    4. 6.4 Device Functional Modes
  8. 7 Register Map
    1. 7.1 LMX1204 Registers
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 SYSREFREQ Input Configuration
      2. 8.1.2 Reducing SYSREF Common Mode Voltages
      3. 8.1.3 Current Consumption
      4. 8.1.4 Treatment of Unused Pins
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curve
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device 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. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information
6.3.6.1.1 SYSREF Output Buffers for Main Clocks (SYSREFOUT)

The SYSREF outputs within the clock output channels have the same output buffer structure as the clock output buffer, with the addition of circuitry to adjust the common-mode voltage. The SYSREF outputs are CML outputs with a common-mode voltage that can be adjusted with the SYSREFOUTx_VCM field, and the output level that can be programmed with the SYSREFOUTx_PWR field. This feature is to allow DC coupling. Note that the CLKOUT outputs do not have adjustable common-mode voltage and must be AC coupled for optimal noise performance.

GUID-20220808-SS0I-X5R1-W27Z-BFP9CJJVJM0C-low.svg Figure 6-7 SYSREF Output Buffer

The common-mode voltage and output power are interrelated and can be simulated assuming a 100Ω differential load and no DC path to ground. The common mode voltage and output are interrelated as shown in Table 6-9. As there is a restriction required for long term reliability that VCM – VOD/2 ≥ 0.5 V combinations of VCM and VOD that do not satisfy this constraint are excluded from the table.

Table 6-9 Single-Ended Voltage (VOD) and Common Mode Voltage (VCM)
SYSREFOUTx_PWR SYSREFOUTx_VCM VOD VCM
0 0 0.31 0.91
1 0.31 1.06
2 0.31 1.23
3 0.32 1.41
4 0.32 1.58
5 0.33 1.75
6 0.33 1.94
7 0.34 2.11
1 0 0.34 0.59
1 0.35 0.76
2 0.35 0.96
3 0.35 1.19
4 0.36 1.39
5 0.36 1.59
6 0.36 1.82
7 0.36 2.03
2 0 0.39 0.46
1 0.42 0.52
2 0.44 0.69
3 0.46 0.96
4 0.46 1.2
5 0.47 1.43
6 0.48 1.7
7 0.49 1.94
3 2 0.48 0.53
3 0.51 0.74
4 0.53 1.02
5 0.54 1.27
6 0.55 1.59
7 0.56 1.87
4 3 0.56 0.59
4 0.59 0.83
5 0.61 1.13
6 0.62 1.47
7 0.64 1.79
5 3 0.58 0.54
4 0.64 0.69
5 0.67 0.98
6 0.69 1.37
7 0.71 1.72
6 5 0.73 0.84
6 0.75 1.26
7 0.78 1.64
7 5 0.78 0.73
6 0.82 1.15
7 0.84 1.57