SNAS688C Februray   2017  – May 2018 LMK04832

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Simplified Schematic
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Timing Diagram
    8. 6.8 Typical Characteristics – Clock Output AC Characteristics
  7. 7 Parameter Measurement Information
    1. 7.1 Charge Pump Current Specification Definitions
      1. 7.1.1 Charge Pump Output Current Magnitude Variation vs Charge Pump Output Voltage
      2. 7.1.2 Charge Pump Sink Current vs Charge Pump Output Source Current Mismatch
      3. 7.1.3 Charge Pump Output Current Magnitude Variation vs Ambient Temperature
    2. 7.2 Differential Voltage Measurement Terminology
  8. 8 Detailed Description
    1. 8.1 Overview
      1. 8.1.1  Differences to LMK0482x
      2. 8.1.2  Jitter Cleaning
      3. 8.1.3  JEDEC JESD204B Support
      4. 8.1.4  Clock Inputs
        1. 8.1.4.1 Three Redundant PLL1 Reference Inputs
        2. 8.1.4.2 PLL2 Reference Inputs
        3. 8.1.4.3 Clock Distribution Reference Input
      5. 8.1.5  VCXO Buffered Output
      6. 8.1.6  Frequency Holdover
      7. 8.1.7  Internal VCOs
      8. 8.1.8  External VCO Mode
      9. 8.1.9  Clock Distribution
        1. 8.1.9.1 Clock Divider
        2. 8.1.9.2 High Performance Divider Bypass Mode
        3. 8.1.9.3 SYSREF Clock Divider
        4. 8.1.9.4 Device Clock Delay
        5. 8.1.9.5 Dynamic Digital Delay
        6. 8.1.9.6 SYSREF Delay: Global and Local
        7. 8.1.9.7 Programmable Output Formats
        8. 8.1.9.8 Clock Output Synchronization
      10. 8.1.10 0-Delay
      11. 8.1.11 Status Pins
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Synchronizing PLL R Dividers
        1. 8.3.1.1 PLL1 R Divider Synchronization
        2. 8.3.1.2 PLL2 R Divider Synchronization
      2. 8.3.2 SYNC/SYSREF
      3. 8.3.3 JEDEC JESD204B
        1. 8.3.3.1 How to Enable SYSREF
          1. 8.3.3.1.1 Setup of SYSREF Example
          2. 8.3.3.1.2 SYSREF_CLR
        2. 8.3.3.2 SYSREF Modes
          1. 8.3.3.2.1 SYSREF Pulser
          2. 8.3.3.2.2 Continuous SYSREF
          3. 8.3.3.2.3 SYSREF Request
      4. 8.3.4 Digital Delay
        1. 8.3.4.1 Fixed Digital Delay
          1. 8.3.4.1.1 Fixed Digital Delay Example
        2. 8.3.4.2 Dynamic Digital Delay
        3. 8.3.4.3 Single and Multiple Dynamic Digital Delay Example
      5. 8.3.5 SYSREF to Device Clock Alignment
      6. 8.3.6 Input Clock Switching
        1. 8.3.6.1 Input Clock Switching - Manual Mode
        2. 8.3.6.2 Input Clock Switching - Pin Select Mode
        3. 8.3.6.3 Input Clock Switching - Automatic Mode
      7. 8.3.7 Digital Lock Detect
        1. 8.3.7.1 Calculating Digital Lock Detect Frequency Accuracy
      8. 8.3.8 Holdover
        1. 8.3.8.1 Enable Holdover
          1. 8.3.8.1.1 Fixed (Manual) CPout1 Holdover Mode
          2. 8.3.8.1.2 Tracked CPout1 Holdover Mode
        2. 8.3.8.2 During Holdover
        3. 8.3.8.3 Exiting Holdover
        4. 8.3.8.4 Holdover Frequency Accuracy and DAC Performance
      9. 8.3.9 PLL2 Loop Filter
    4. 8.4 Device Functional Modes
      1. 8.4.1 DUAL PLL
        1. 8.4.1.1 Dual Loop
        2. 8.4.1.2 Dual Loop With Cascaded 0-Delay
        3. 8.4.1.3 Dual Loop With Nested 0-Delay
      2. 8.4.2 Single PLL
        1. 8.4.2.1 PLL2 Single Loop
        2. 8.4.2.2 PLL2 With External VCO
      3. 8.4.3 Distribution Mode
    5. 8.5 Programming
      1. 8.5.1 Recommended Programming Sequence
    6. 8.6 Register Maps
      1. 8.6.1 Register Map for Device Programming
      2. 8.6.2 Device Register Descriptions
        1. 8.6.2.1 System Functions
          1. 8.6.2.1.1 RESET, SPI_3WIRE_DIS
          2. 8.6.2.1.2 POWERDOWN
          3. 8.6.2.1.3 ID_DEVICE_TYPE
          4. 8.6.2.1.4 ID_PROD
          5. 8.6.2.1.5 ID_MASKREV
          6. 8.6.2.1.6 ID_VNDR
        2. 8.6.2.2 (0x100 - 0x138) Device Clock and SYSREF Clock Output Controls
          1. 8.6.2.2.1 DCLKX_Y_DIV
          2. 8.6.2.2.2 DCLKX_Y_DDLY
          3. 8.6.2.2.3 CLKoutX_Y_PD, CLKoutX_Y_ODL, CLKoutX_Y_IDL, DCLKX_Y_DDLY_PD, DCLKX_Y_DDLY[9:8], DCLKX_Y_DIV[9:8]
          4. 8.6.2.2.4 CLKoutX_SRC_MUX, CLKoutX_Y_PD, DCLKX_Y_BYP, DCLKX_Y_DCC, DCLKX_Y_POL, DCLKX_Y_HS
          5. 8.6.2.2.5 CLKoutY_SRC_MUX, SCLKX_Y_PD, SCLKX_Y_DIS_MODE, SCLKX_Y_POL, SCLKX_Y_HS
          6. 8.6.2.2.6 SCLKX_Y_ADLY_EN, SCLKX_Y_ADLY
          7. 8.6.2.2.7 SCLKX_Y_DDLY
          8. 8.6.2.2.8 CLKoutY_FMT, CLKoutX_FMT
        3. 8.6.2.3 SYSREF, SYNC, and Device Config
          1. 8.6.2.3.1  VCO_MUX, OSCout_MUX, OSCout_FMT
          2. 8.6.2.3.2  SYSREF_REQ_EN, SYNC_BYPASS, SYSREF_MUX
          3. 8.6.2.3.3  SYSREF_DIV
          4. 8.6.2.3.4  SYSREF_DDLY
          5. 8.6.2.3.5  SYSREF_PULSE_CNT
          6. 8.6.2.3.6  PLL2_RCLK_MUX, PLL2_NCLK_MUX, PLL1_NCLK_MUX, FB_MUX, FB_MUX_EN
          7. 8.6.2.3.7  PLL1_PD, VCO_LDO_PD, VCO_PD, OSCin_PD, SYSREF_GBL_PD, SYSREF_PD, SYSREF_DDLY_PD, SYSREF_PLSR_PD
          8. 8.6.2.3.8  DDLYdSYSREF_EN, DDLYdX_EN
          9. 8.6.2.3.9  DDLYd_STEP_CNT
          10. 8.6.2.3.10 SYSREF_CLR, SYNC_1SHOT_EN, SYNC_POL, SYNC_EN, SYNC_PLL2_DLD, SYNC_PLL1_DLD, SYNC_MODE
          11. 8.6.2.3.11 SYNC_DISSYSREF, SYNC_DISX
          12. 8.6.2.3.12 PLL1R_SYNC_EN, PLL1R_SYNC_SRC, PLL2R_SYNC_EN
        4. 8.6.2.4 (0x146 - 0x149) CLKin Control
          1. 8.6.2.4.1 CLKin_SEL_PIN_EN, CLKin_SEL_PIN_POL, CLKin2_EN, CLKin1_EN, CLKin0_EN, CLKin2_TYPE, CLKin1_TYPE, CLKin0_TYPE
          2. 8.6.2.4.2 CLKin_SEL_AUTO_REVERT_EN, CLKin_SEL_AUTO_EN, CLKin_SEL_MANUAL, CLKin1_DEMUX, CLKin0_DEMUX
          3. 8.6.2.4.3 CLKin_SEL0_MUX, CLKin_SEL0_TYPE
          4. 8.6.2.4.4 SDIO_RDBK_TYPE, CLKin_SEL1_MUX, CLKin_SEL1_TYPE
        5. 8.6.2.5 RESET_MUX, RESET_TYPE
        6. 8.6.2.6 (0x14B - 0x152) Holdover
          1. 8.6.2.6.1 LOS_TIMEOUT, LOS_EN, TRACK_EN, HOLDOVER_FORCE, MAN_DAC_EN, MAN_DAC[9:8]
          2. 8.6.2.6.2 MAN_DAC
          3. 8.6.2.6.3 DAC_TRIP_LOW
          4. 8.6.2.6.4 DAC_CLK_MULT, DAC_TRIP_HIGH
          5. 8.6.2.6.5 DAC_CLK_CNTR
          6. 8.6.2.6.6 CLKin_OVERRIDE, HOLDOVER_EXIT_MODE, HOLDOVER_PLL1_DET, LOS_EXTERNAL_INPUT, HOLDOVER_VTUNE_DET, CLKin_SWITCH_CP_TRI, HOLDOVER_EN
          7. 8.6.2.6.7 HOLDOVER_DLD_CNT
        7. 8.6.2.7 (0x153 - 0x15F) PLL1 Configuration
          1. 8.6.2.7.1 CLKin0_R
          2. 8.6.2.7.2 CLKin1_R
          3. 8.6.2.7.3 CLKin2_R
          4. 8.6.2.7.4 PLL1_N
          5. 8.6.2.7.5 PLL1_WND_SIZE, PLL1_CP_TRI, PLL1_CP_POL, PLL1_CP_GAIN
          6. 8.6.2.7.6 PLL1_DLD_CNT
          7. 8.6.2.7.7 HOLDOVER_EXIT_NADJ
          8. 8.6.2.7.8 PLL1_LD_MUX, PLL1_LD_TYPE
        8. 8.6.2.8 (0x160 - 0x16E) PLL2 Configuration
          1. 8.6.2.8.1 PLL2_R
          2. 8.6.2.8.2 PLL2_P, OSCin_FREQ, PLL2_REF_2X_EN
          3. 8.6.2.8.3 PLL2_N_CAL
          4. 8.6.2.8.4 PLL2_N
          5. 8.6.2.8.5 PLL2_WND_SIZE, PLL2_CP_GAIN, PLL2_CP_POL, PLL2_CP_TRI
          6. 8.6.2.8.6 PLL2_DLD_CNT
          7. 8.6.2.8.7 PLL2_LD_MUX, PLL2_LD_TYPE
        9. 8.6.2.9 (0x16F - 0x555) Misc Registers
          1. 8.6.2.9.1 PLL2_PRE_PD, PLL2_PD
          2. 8.6.2.9.2 PLL1R_RST
          3. 8.6.2.9.3 CLR_PLL1_LD_LOST, CLR_PLL2_LD_LOST
          4. 8.6.2.9.4 RB_PLL1_LD_LOST, RB_PLL1_LD, RB_PLL2_LD_LOST, RB_PLL2_LD
          5. 8.6.2.9.5 RB_DAC_VALUE (MSB), RB_CLKinX_SEL, RB_CLKinX_LOS
          6. 8.6.2.9.6 RB_DAC_VALUE
          7. 8.6.2.9.7 RB_HOLDOVER
          8. 8.6.2.9.8 SPI_LOCK
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Digital Lock Detect Frequency Accuracy
        1. 9.1.1.1 Minimum Lock Time Calculation Example
      2. 9.1.2 Driving CLKin AND OSCin Inputs
        1. 9.1.2.1 Driving CLKin and OSCin PINS With a Differential Source
        2. 9.1.2.2 Driving CLKin Pins With a Single-Ended Source
      3. 9.1.3 OSCin Doubler for Best Phase Noise Performance
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Device Selection
          1. 9.2.2.1.1 Clock Architect
        2. 9.2.2.2 Device Configuration and Simulation
        3. 9.2.2.3 Device Programming
      3. 9.2.3 Application Curves
    3. 9.3 Do's and Don'ts
      1. 9.3.1 Pin Connection Recommendations
  10. 10Power Supply Recommendations
    1. 10.1 Current Consumption
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Thermal Management
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Development Support
        1. 12.1.1.1 Clock Architect
        2. 12.1.1.2 PLLatinum Sim
        3. 12.1.1.3 TICS Pro
    2. 12.2 Community Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.2 SYNC/SYSREF

The SYNC and SYSREF signals share the same SYNC/SYSREF Clock Distribution path. To properly use SYNC and/or SYSREF for JESD204B it is important to understand the SYNC/SYSREF system. Figure 7 illustrates the detailed diagram of a clock output block with SYNC circuitry included. Figure 8 illustrates the interconnects and highlights some important registers used in controlling the device for SYNC/SYSREF purposes.

To reset or synchronize a divider, the following conditions must be met:

  1. SYNC_EN must be set. This ensures proper operation of the SYNC circuitry.
  2. SYSREF_MUX and SYNC_MODE must be set to a proper combination to provide a valid SYNC/SYSREF signal.
    • If SYSREF block is being used, the SYSREF_PD bit must be clear.
    • If the SYSREF Pulser is being used, the SYSREF_PLSR_PD bit must be clear.
    • For each CLKoutX or CLKoutY being used for SYSREF, the respective SCLKX_Y_PD bit must be cleared.
  3. DCLKX_Y_DDLY_PD and SYSREF_DDLY_PD bits must be clear to power up the digital delay circuitry used during SYNC to cause deterministic phase between the device clock dividers and the global SYSREF divider.
  4. The SYNC_DISX bit must be clear to allow SYNC/SYSREF signal to divider circuit. The SYSREF_MUX register selects the SYNC source which resets the SYSREF/CLKoutX dividers provided the corresponding SYNC_DISX bit is clear.
  5. Other bits which impact the operation of SYNC such as SYNC_1SHOT_EN may be set as desired.
  6. After these dividers are synchronized, the DCLKX_Y_DDLY_PD and SYSREF_DDLY_PD bits may be set to save current. Clearing them to power up may disrupt the output clock phase.

Table 1 illustrates the some possible combinations of SYSREF_MUX and SYNC_MODE.

Table 1. Some Possible SYNC Configurations

NAME SYNC_MODE SYSREF_MUX OTHER DESCRIPTION
SYNC Disabled 0 0 CLKin0_DEMUX ≠ 0 No SYNC will occur.
Pin or SPI SYNC 1 0 CLKin0_DEMUX ≠ 0 Basic SYNC functionality, SYNC pin polarity is selected by SYNC_POL.
To achieve SYNC through SPI, toggle the SYNC_POL bit.
Differential input SYNC X 0 or 1 CLKin0_DEMUX = 0 Differential CLKin0 now operates as SYNC input.
JESD204B Pulser on pin transition. 2 2 SYSREF_PULSE_CNT sets pulse count Produce SYSREF_PULSE_CNT programmed number of pulses on pin transition. SYNC_POL can be used to cause SYNC through SPI.
JESD204B Pulser on SPI programming. 3 2 SYSREF_PULSE_CNT sets pulse count Programming SYSREF_PULSE_CNT register starts sending the number of pulses.
Re-clocked SYNC 1 1 SYSREF operational, SYSREF Divider as required for training frame size. Allows precise SYNC for n-bit frame training patterns for non-JESD converters such as LM97600.
External SYSREF request 0 2 SYSREF_REQ_EN = 1
Pulser powered up		 When SYNC pin is asserted, continuous SYSERF pulses occur. Turning on and off of the pulses is synchronized to prevent runt pulses from occurring on SYSREF.
Continuous SYSREF X 3 SYSREF_PD = 0
SYSREF_DDLY_PD = 0
SYSREF_PLSR_PD = 1 (1) 		Continuous SYSREF signal.
Re-clocked SYSREF distribution 0 0 SYSREF_DDLY_PD = 1
SYSREF_PLSR_PD = 1
SYSREF_PD = 1. 		Fan-out of CLKin0 reclocked to the clock distribution path.
(1) SCLKX_Y_PD = 0 as required per SYSREF output. This applies to any SYNC or SYSREF output on SCLKX_Y when SCLKX_Y_MUX = 1 (SYSREF output)

NOTE

Because the SYNC/SYSREF signal is reclocked by the Clock Distribution Path, an active clock must be present on the Clock Distribution Path (either from VCO or CLKin1/Fin pins in distribution mode) for SYNC to take effect.

NOTE

Any device clock divider or the SYSREF divider which does not have the SYNC_DISX bit or SYNC_DISSYSREF bit set will reset while SYNC/SYSREF Distribution Path is high. This is especially important for the SYSREF divider which has the ability to reset itself if the SYNC_DISSYSREF = 0! Be sure to set SYNC_DISX/SYNC_DISSYSREF bits as required.

NOTE

While using Divide-by-2 or Divide-by-3 for DCLK_X_Y_DIV, SYNC procedure requires to first program Divide-by-4 and then back to Divide-by-2 or Divide-by-3 before doing SYNC.