SNAS880A December   2024  – October 2025 LMK3C0105

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
  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 Digital State Machine
        3. 7.4.2.3 Spread-Spectrum Clocking
        4. 7.4.2.4 Integer Boundary Spurs
      3. 7.4.3 Output Behavior
        1. 7.4.3.1 Output Format Selection
        2. 7.4.3.2 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 Separate 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 = 0x1804]
      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 = 0x0AA7]
      8. 8.1.8  R7 Register (Address = 0x7) [reset = 0x5D1F]
      9. 8.1.9  R8 Register (Address = 0x8) [reset = 0xC28F]
      10. 8.1.10 R9 Register (Address = 0x9) [reset = 0x3000/0x1000]
      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 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
    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

7.3.4 I2C Mode

In this mode, I2C is enabled and the SCA and SDL pins function as the I2C clock and I2C data pins, respectively. Table 7-2 shows the four default I2C addresses selectable by the I2C_ADDR pin. The 5 MSBs of the I2C address are set in the upper five bits of I2C_ADDR (R12[14:8]).

If I2C_ADDR_LSB_SEL (R12[15]) = 0, then the I2C_ADDR pin is ignored, and the I2C address is solely determined by I2C_ADDR.

Table 7-2 I2C Address Selection
REF_CTRL PIN(1)I2C_ADDR PINI2C ADDRESS(2)
HighX

N/A

(I2C disabled)

Low00x68 / 0xD0
Low10x69 / 0xD2
LowTied to SDA0x6A / 0xD4
LowTied to SCL0x6B / 0xD8
(1) This is the state of the REF_CTRL pin at power-up, not the live pin state.
(2) The 0xD0, 0xD2, 0xD4, and 0xD8 addresses are with the R/W bit included set to '0'.

When changing the registers of the device, first set PDN to '1', write to the device registers, then set PDN to '0'. Figure 7-4 shows this process.

LMK3C0105 LMK3C0105 Programming Sequence Figure 7-4 LMK3C0105 Programming Sequence