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

8.2 Differential Voltage Measurement Terminology

The differential voltage of a differential signal can be described by two different definitions causing confusion when reading data sheets or communicating with other engineers. This section will address the measurement and description of a differential signal so that the reader will be able to understand and distinguish between the two different definitions when used.

The first definition used to describe a differential signal is the absolute value of the voltage potential between the inverting and noninverting signal. The symbol for this first measurement is typically VID or VOD depending on if an input or output voltage is being described.

The second definition used to describe a differential signal is to measure the potential of the noninverting signal with respect to the inverting signal. The symbol for this second measurement is VSS and is a calculated parameter. Nowhere in the IC does this signal exist with respect to ground, it only exists in reference to its differential pair. VSS can be measured directly by oscilloscopes with floating references, otherwise this value can be calculated as twice the value of VOD as described in the first description.

Figure 2 illustrates the two different definitions side-by-side for inputs and Figure 3 illustrates the two different definitions side-by-side for outputs. The VID and VOD definitions show VA and VB DC levels that the noninverting and inverting signals toggle between with respect to ground. VSS input and output definitions show that if the inverting signal is considered the voltage potential reference, the noninverting signal voltage potential is now increasing and decreasing above and below the noninverting reference. Thus the peak-to-peak voltage of the differential signal can be measured.

VID and VOD are often defined as volts (V) and VSS is often defined as volts peak-to-peak (VPP).

LMK04228 two_different_definitions_differential_input_signals_SNAS968.gifFigure 2. Two Different Definitions for
Differential Input Signals
LMK04228 two_different_definitions_differential_output_signals_SNAS968.gifFigure 3. Two Different Definitions for
Differential Output Signals

Refer to application note AN-912 Common Data Transmission Parameters and their Definitions (SNLA036) for more information.