SNAS847E November   2023  – October 2025 LMK3H0102

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 I2C Interface Specification
  7. 6 Parameter Measurement Information
    1. 6.1 Output Format Configurations
    2. 6.2 Differential Voltage Measurement Terminology
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Device Block-Level Description
      2. 7.3.2 Device Configuration Control
      3. 7.3.3 OTP Mode
      4. 7.3.4 I2C Mode
    4. 7.4 Device Functional Modes
      1. 7.4.1 Fail-Safe Inputs
      2. 7.4.2 Fractional Output Dividers
        1. 7.4.2.1 FOD Operation
        2. 7.4.2.2 Edge Combiner
        3. 7.4.2.3 Digital State Machine
        4. 7.4.2.4 Spread-Spectrum Clocking
        5. 7.4.2.5 Integer Boundary Spurs
      3. 7.4.3 Output Behavior
        1. 7.4.3.1 Output Format Selection
          1. 7.4.3.1.1 Output Format Types
            1. 7.4.3.1.1.1 LP-HCSL Termination
        2. 7.4.3.2 Output Slew Rate Control
        3. 7.4.3.3 REF_CTRL Operation
      4. 7.4.4 Output Enable
        1. 7.4.4.1 Output Enable Control
        2. 7.4.4.2 Output Enable Polarity
        3. 7.4.4.3 Individual Output Enable
        4. 7.4.4.4 Output Disable Behavior
      5. 7.4.5 Device Default Settings
    5. 7.5 Programming
      1. 7.5.1 I2C Serial Interface
      2. 7.5.2 One-Time Programming Sequence
  9. 8 Device Registers
    1. 8.1 Register Maps
      1. 8.1.1  R0 Register (Address = 0x0) [reset = 0x0861/0x0863]
      2. 8.1.2  R1 Register (Address = 0x1) [reset = 0x5599]
      3. 8.1.3  R2 Register (Address = 0x2) [reset = 0xC28F]
      4. 8.1.4  R3 Register (Address = 0x3) [reset = 0x1801]
      5. 8.1.5  R4 Register (Address = 0x4) [reset = 0x0000]
      6. 8.1.6  R5 Register (Address = 0x5) [reset = 0x0000]
      7. 8.1.7  R6 Register (Address = 0x6) [reset = 0x0AA0]
      8. 8.1.8  R7 Register (Address = 0x7) [reset = 0x6503]
      9. 8.1.9  R8 Register (Address = 0x8) [reset = 0xC28F]
      10. 8.1.10 R9 Register (Address = 0x9) [reset = 0x3166]
      11. 8.1.11 R10 Register (Address = 0xA) [reset = 0x0010]
      12. 8.1.12 R11 Register (Address = 0xB) [reset = 0x0000]
      13. 8.1.13 R12 Register (Address = 0xC) [reset = 0xE800]
      14. 8.1.14 R146 Register (Address = 0x92) [reset = 0x0000]
      15. 8.1.15 R147 Register (Address = 0x93) [reset = 0x0000]
      16. 8.1.16 R148 Register (Address = 0x94) [reset = 0x0000]
      17. 8.1.17 R238 Register (Address = 0xEE) [reset = 0x0000]
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Application Block Diagram Examples
      2. 9.2.2 Design Requirements
      3. 9.2.3 Detailed Design Procedure
      4. 9.2.4 Example: Changing Output Frequency
      5. 9.2.5 Crosstalk
      6. 9.2.6 Application Curves
    3. 9.3 Power Supply Recommendations
      1. 9.3.1 Power-Up Sequencing
      2. 9.3.2 Decoupling Power Supply Inputs
    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

7.1 Overview

The LMK3H0102 is a dual-channel clock generator primarily used for PCIe Gen 1 to Gen 7 clock generation, either with or without Spread Spectrum Clocking (SSC). The device has an integrated Bulk Acoustic Wave (BAW) resonator and does not require any external crystal or clock reference. The device has four selectable pages of memory, referred to as OTP pages. The collection of these pages in memory is referred to as the EFUSE.

The default output configuration is two 100MHz clocks, each with a 100Ω LP-HCSL output format, both disabled at start-up. The LMK3H0102 supports 100Ω LP-HCSL, 85Ω LP-HCSL, LVDS and 1.8V, 2.5V, or 3.3V LVCMOS output formats, as well as programmable output frequencies up to 200MHz for single-ended outputs and 400MHz for differential outputs. The LMK3H0102V33 is the part number for the default configuration with a 3.3V supply voltage. The LMK3H0102LMK3H0102V18 is the part number for the default configuration with a 1.8V supply voltage. Additional configuration part numbers are LMK3H0102Axxx, where xxx denotes the configuration number. LMK3H0102 Configuration Guide details the critical device settings and default register settings for each LMK3H0102Axxx OTP configuration.

The LMK3H0102 supports two functional modes determined by the REF_CTRL pin at power-up: One-Time Programming (OTP) mode or I2C mode.

  1. In OTP mode, one out of four OTP pages is selected by pins OTP_SEL0 and OTP_SEL1. The default output frequency across all OTP pages is 100MHz.
  2. In I2C mode, the LMK3H0102 is configured by modifying the active registers. If a configuration other than the default operation is desired, the registers must be written every time at start-up.
Refer to Pin Configuration and Functions for the detailed descriptions of the device pins.

The LMK3H0102 has flexible SSC configurations, including:

  1. SSC disabled on both outputs
  2. SSC enabled on both outputs
  3. SSC enabled on a single output
The SSC specifications and jitter performance are fully compliant to PCIe Gen 1 to Gen 7. Refer to Spread-Spectrum Clocking for SSC and jitter performance details.