SNAS689A October   2017  – July 2019 LMK04228

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Simplified Schematic
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 SPI Interface Timing
    7. 7.7 Timing Diagram
  8. 8 Parameter Measurement Information
    1. 8.1 Charge Pump Current Specification Definitions
      1. 8.1.1 Charge Pump Output Current Magnitude Variation vs. Charge Pump Output Voltage
      2. 8.1.2 Charge Pump Sink Current vs. Charge Pump Output Source Current Mismatch
      3. 8.1.3 Charge Pump Output Current Magnitude Variation vs. Ambient Temperature
    2. 8.2 Differential Voltage Measurement Terminology
  9. 9 Detailed Description
    1. 9.1 Overview
      1. 9.1.1 Jitter Cleaning
      2. 9.1.2 JEDEC JESD204B Support
      3. 9.1.3 Three PLL1 Redundant Reference Inputs (CLKin0/CLKin0*, CLKin1/CLKin1*, and CLKin2/CLKin2*)
      4. 9.1.4 VCXO- and Crystal-Buffered Output
      5. 9.1.5 Frequency Holdover
      6. 9.1.6 PLL2 Integrated Loop Filter Poles
      7. 9.1.7 Internal VCOs
      8. 9.1.8 Clock Distribution
        1. 9.1.8.1 Device Clock Divider
        2. 9.1.8.2 SYSREF Clock Divider
        3. 9.1.8.3 Device Clock Delay
        4. 9.1.8.4 SYSREF Delay
        5. 9.1.8.5 Programmable Output Formats
        6. 9.1.8.6 Clock Output Synchronization
      9. 9.1.9 Status Pins
    2. 9.2 Functional Block Diagrams
    3. 9.3 Feature Description
      1. 9.3.1 SYNC/SYSREF
      2. 9.3.2 JEDEC JESD204B
        1. 9.3.2.1 How to Enable SYSREF
          1. 9.3.2.1.1 Setup of SYSREF Example
          2. 9.3.2.1.2 SYSREF_CLR
        2. 9.3.2.2 SYSREF Modes
          1. 9.3.2.2.1 SYSREF Pulser
          2. 9.3.2.2.2 Continuous SYSREF
          3. 9.3.2.2.3 SYSREF Request
      3. 9.3.3 Digital Delay
        1. 9.3.3.1 Fixed Digital Delay
          1. 9.3.3.1.1 Fixed Digital Delay Example
      4. 9.3.4 SYSREF to Device Clock Alignment
      5. 9.3.5 Input Clock Switching
        1. 9.3.5.1 Input Clock Switching - Manual Mode
        2. 9.3.5.2 Input Clock Switching - Pin Select Mode
          1. 9.3.5.2.1 Configuring Pin Select Mode
        3. 9.3.5.3 Input Clock Switching - Automatic Mode
          1. 9.3.5.3.1 Starting Active Clock
      6. 9.3.6 Digital Lock Detect
        1. 9.3.6.1 Calculating Digital Lock Detect Frequency Accuracy
      7. 9.3.7 Holdover
        1. 9.3.7.1 Enable Holdover
          1. 9.3.7.1.1 Fixed (Manual) CPout1 Holdover Mode
          2. 9.3.7.1.2 Tracked CPout1 Holdover Mode
        2. 9.3.7.2 During Holdover
        3. 9.3.7.3 Exiting Holdover
        4. 9.3.7.4 Holdover Frequency Accuracy and DAC Performance
        5. 9.3.7.5 Holdover Mode - Automatic Exit of Holdover
    4. 9.4 Programming
      1. 9.4.1 Recommended Programming Sequence
        1. 9.4.1.1 SPI LOCK
        2. 9.4.1.2 SYSREF_CLR
    5. 9.5 Register Maps
      1. 9.5.1 Register Map for Device Programming
      2. 9.5.2 Device Register Descriptions
        1. 9.5.2.1 System Functions
          1. 9.5.2.1.1 RESET, SPI_3WIRE_DIS
          2. 9.5.2.1.2 POWERDOWN
          3. 9.5.2.1.3 ID_DEVICE_TYPE
          4. 9.5.2.1.4 ID_PROD[15:8], ID_PROD
          5. 9.5.2.1.5 ID_MASKREV
          6. 9.5.2.1.6 ID_VNDR[15:8], ID_VNDR
        2. 9.5.2.2 (0x100 - 0x138) Device Clock and SYSREF Clock Output Controls
          1. 9.5.2.2.1 CLKoutX_Y_ODL, CLKoutX_Y_IDL, DCLKoutX_DIV
          2. 9.5.2.2.2 DCLKoutX_DDLY_CNTH, DCLKoutX_DDLY_CNTL
          3. 9.5.2.2.3 DCLKoutX_ADLY, DCLKoutX_ADLY_MUX, DCLKout_MUX
          4. 9.5.2.2.4 DCLKoutX_HS, SDCLKoutY_MUX, SDCLKoutY_DDLY, SDCLKoutY_HS
          5. 9.5.2.2.5 SDCLKoutY_ADLY_EN, SDCLKoutY_ADLY
          6. 9.5.2.2.6 DCLKoutX_DDLY_PD, DCLKout_ADLY_PD, DCLKoutX_Y_PD, SDCLKoutY_DIS_MODE, SDCLKoutY_PD
          7. 9.5.2.2.7 SDCLKoutY_POL, SDCLKoutY_FMT, DCLKoutX_POL, DCLKoutX_FMT
        3. 9.5.2.3 SYSREF, SYNC, and Device Config
          1. 9.5.2.3.1 VCO_MUX, OSCout_FMT
          2. 9.5.2.3.2 SYSREF_CLKin0_MUX, SYSREF_MUX
          3. 9.5.2.3.3 SYSREF_DIV[12:8], SYSREF_DIV[7:0]
          4. 9.5.2.3.4 SYSREF_DDLY[12:8], SYSREF_DDLY[7:0]
          5. 9.5.2.3.5 SYSREF_PULSE_CNT
          6. 9.5.2.3.6 PLL1_PD, VCO_LDO_PD, VCO_PD, OSCin_PD, SYSREF_GBL_PD, SYSREF_PD, SYSREF_DDLY_PD, SYSREF_PLSR_PD
          7. 9.5.2.3.7 SYSREF_CLR, SYNC_1SHOT_EN, SYNC_POL, SYNC_EN, SYNC_PLL2_DLD, SYNC_PLL1_DLD, SYNC_MODE
          8. 9.5.2.3.8 SYNC_DISSYSREF, SYNC_DISX
          9. 9.5.2.3.9 Fixed Register
        4. 9.5.2.4 (0x146 - 0x149) CLKin Control
          1. 9.5.2.4.1 CLKin2_EN, CLKin1_EN, CLKin0_EN, CLKin2_TYPE, CLKin1_TYPE, CLKin0_TYPE
          2. 9.5.2.4.2 CLKin_SEL_POL, CLKin_SEL_MODE, CLKin1_OUT_MUX, CLKin0_OUT_MUX
          3. 9.5.2.4.3 CLKin_SEL0_MUX, CLKin_SEL0_TYPE
          4. 9.5.2.4.4 SDIO_RDBK_TYPE, CLKin_SEL1_MUX, CLKin_SEL1_TYPE
        5. 9.5.2.5 RESET_MUX, RESET_TYPE
        6. 9.5.2.6 (0x14B - 0x152) Holdover
          1. 9.5.2.6.1 LOS_TIMEOUT, LOS_EN, TRACK_EN, HOLDOVER_FORCE, MAN_DAC_EN, MAN_DAC[9:8]
          2. 9.5.2.6.2 MAN_DAC[9:8], MAN_DAC[7:0]
          3. 9.5.2.6.3 DAC_TRIP_LOW
          4. 9.5.2.6.4 DAC_CLK_MULT, DAC_TRIP_HIGH
          5. 9.5.2.6.5 DAC_CLK_CNTR
          6. 9.5.2.6.6 CLKin_OVERRIDE, HOLDOVER_PLL1_DET, HOLDOVER_LOS_DET, HOLDOVER_VTUNE_DET, HOLDOVER_HITLESS_SWITCH, HOLDOVER_EN
          7. 9.5.2.6.7 HOLDOVER_DLD_CNT[13:8], HOLDOVER_DLD_CNT[7:0]
        7. 9.5.2.7 (0x153 - 0x15F) PLL1 Configuration
          1. 9.5.2.7.1 CLKin0_R[9:8], CLKin0_R[7:0]
          2. 9.5.2.7.2 CLKin1_R[9:8], CLKin1_R[7:0]
          3. 9.5.2.7.3 CLKin2_R[9:8], CLKin2_R[7:0]
          4. 9.5.2.7.4 PLL1_N
          5. 9.5.2.7.5 PLL1_WND_SIZE, PLL1_CP_TRI, PLL1_CP_POL, PLL1_CP_GAIN
          6. 9.5.2.7.6 PLL1_DLD_CNT[13:8], PLL1_DLD_CNT[7:0]
          7. 9.5.2.7.7 PLL1_LD_MUX, PLL1_LD_TYPE
        8. 9.5.2.8 (0x160 - 0x16E) PLL2 Configuration
          1. 9.5.2.8.1 PLL2_R[4:0]
          2. 9.5.2.8.2 PLL2_P, OSCin_FREQ, PLL2_XTAL_EN, PLL2_REF_2X_EN
          3. 9.5.2.8.3 PLL2_FCAL_DIS
          4. 9.5.2.8.4 PLL2_N
          5. 9.5.2.8.5 PLL2_WND_SIZE, PLL2_CP_GAIN, PLL2_CP_POL, PLL2_CP_TRI
          6. 9.5.2.8.6 SYSREF_REQ_EN, PLL2_DLD_CNT
          7. 9.5.2.8.7 PLL2_LF_R4, PLL2_LF_R3
          8. 9.5.2.8.8 PLL2_LF_C4, PLL2_LF_C3
          9. 9.5.2.8.9 PLL2_LD_MUX, PLL2_LD_TYPE
        9. 9.5.2.9 (0x16F - 0x1FFF) Misc Registers
          1. 9.5.2.9.1  Fixed Register
          2. 9.5.2.9.2  Fixed Register
          3. 9.5.2.9.3  PLL2_PRE_PD, PLL2_PD
          4. 9.5.2.9.4  OPT_REG_1
          5. 9.5.2.9.5  OPT_REG_2
          6. 9.5.2.9.6  RB_PLL1_LD_LOST, RB_PLL1_LD, CLR_PLL1_LD_LOST
          7. 9.5.2.9.7  RB_PLL2_LD_LOST, RB_PLL2_LD, CLR_PLL2_LD_LOST
          8. 9.5.2.9.8  RB_DAC_VALUE(MSB), RB_CLKinX_SEL, RB_CLKinX_LOS
          9. 9.5.2.9.9  RB_DAC_VALUE
          10. 9.5.2.9.10 RB_HOLDOVER
          11. 9.5.2.9.11 SPI_LOCK
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Digital Lock Detect Frequency Accuracy
        1. 10.1.1.1 Minimum Lock Time Calculation Example
      2. 10.1.2 Driving CLKin AND OSCin Inputs
        1. 10.1.2.1 Driving CLKin PINS With a Differential Source
        2. 10.1.2.2 Driving CLKin Pins With a Single-Ended Source
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Device Programming
    3. 10.3 Do's and Don'ts
      1. 10.3.1 Pin Connection Recommendations
  11. 11Power Supply Recommendations
    1. 11.1 Current Consumption / Power Dissipation Calculations
  12. 12Layout
    1. 12.1 Layout Guidelines
      1. 12.1.1 Thermal Management
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 TICS Pro
    2. 13.2 Community Resources
    3. 13.3 Trademarks
    4. 13.4 Electrostatic Discharge Caution
    5. 13.5 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

10.2.2.1 Device Programming

TICS Pro register programming tool exposes the registers for the LMK04228 (and many other TI products) using block diagrams to demonstrate the purpose and location of register settings. By connecting a USB2ANY programmer to the SPI inputs of the device, TICS Pro can update register configurations in real time for rapidly validating desired configurations.

Frequency planning for assignment of outputs:

  • To minimize crosstalk perform frequency planning / CLKout assignments to keep common frequencies on outputs close together.
  • It is best to place common device clock output frequencies on outputs sharing the same VCC group, for example, these outputs share Vcc4_CG2. Refer to Pin Configuration and Functions to see the VCC groupings the clock outputs.

In this example, the 245.76-MHz ADC output needs the best performance. DCLKout2 on the LMK04228 provides the best noise floor / performance. The 245.76 MHz will be placed on DCLKout2 with 10.24-MHz SYSREF on SDCLKout3.

  • For best performance the input and output drive level bits may be set. Best noise floor performance is achieved with DCLKout2_IDL = 1 and DCLKout2_ODL = 1.

In this example, the 983.04-MHz DAC output is placed on DCLKout4 and DCLKout6 with 10.24-MHz SYSREF on paired SDCLKout5 and SDCLKout7 outputs.

  • These outputs share Vcc4_CG2.

In this example, the 122.88-MHz FPGA JESD204B output is placed on DCLKout10 with 10.24-MHz SYSREF on paired SDCLKout11 output.

Additionally, the 122.88-MHz FPGA non-JESD204B outputs are placed on DCLKout8 and SDCLKout9.

  • When frequency planning, consider PLL2 as a clock output at the phase detector frequency. As such, these 122.88-MHz outputs have been placed on the outputs close to the PLL2 and Charge Pump power supplies.

Once the device programming is completed as desired in TICS Pro, the register settings can be exported for use with other programming controllers.