SNAS736C June   2017  – April 2019 LMX2595


  1. Features
  2. Applications
  3. Description
    1.     Device Images
      1.      Simplified Schematic
  4. Revision History
  5. Pin Configuration and Functions
    1.     Pin Functions
  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 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Reference Oscillator Input
      2. 7.3.2  Reference Path
        1. OSCin Doubler (OSC_2X)
        2. Pre-R Divider (PLL_R_PRE)
        3. Programmable Multiplier (MULT)
        4. Post-R Divider (PLL_R)
        5. State Machine Clock
      3. 7.3.3  PLL Phase Detector and Charge Pump
      4. 7.3.4  N-Divider and Fractional Circuitry
      5. 7.3.5  MUXout Pin
        1. Lock Detect
        2. Readback
      6. 7.3.6  VCO (Voltage-Controlled Oscillator)
        1. VCO Calibration
        2. Determining the VCO Gain
      7. 7.3.7  Channel Divider
      8. 7.3.8  VCO Doubler
      9. 7.3.9  Output Buffer
      10. 7.3.10 Power-Down Modes
      11. 7.3.11 Phase Synchronization
        1. General Concept
        2. Categories of Applications for SYNC
        3. Procedure for Using SYNC
        4. SYNC Input Pin
      12. 7.3.12 Phase Adjust
      13. 7.3.13 Fine Adjustments for Phase Adjust and Phase SYNC
      14. 7.3.14 Ramping Function
        1. Manual Pin Ramping
          1. Manual Pin Ramping Example
        2. Automatic Ramping
          1. Automatic Ramping Example (Triangle Wave)
      15. 7.3.15 SYSREF
        1. Programmable Fields
        2. Input and Output Pin Formats
          1. Input Format for SYNC and SysRefReq Pins
          2. SYSREF Output Format
        3. Examples
        4. SYSREF Procedure
      16. 7.3.16 SysRefReq Pin
    4. 7.4 Device Functional Modes
    5. 7.5 Programming
      1. 7.5.1 Recommended Initial Power-Up Sequence
      2. 7.5.2 Recommended Sequence for Changing Frequencies
      3. 7.5.3 General Programming Requirements
    6. 7.6 Register Maps
      1. 7.6.1  General Registers R0, R1, & R7
        1. Table 25. Field Descriptions
      2. 7.6.2  Input Path Registers
        1. Table 26. Field Descriptions
      3. 7.6.3  Charge Pump Registers (R13, R14)
        1. Table 27. Field Descriptions
      4. 7.6.4  VCO Calibration Registers
        1. Table 28. Field Descriptions
      5. 7.6.5  N Divider, MASH, and Output Registers
        1. Table 29. Field Descriptions
      6. 7.6.6  SYNC and SysRefReq Input Pin Register
        1. Table 30. Field Descriptions
      7. 7.6.7  Lock Detect Registers
        1. Table 31. Field Descriptions
      8. 7.6.8  MASH_RESET
        1. Table 32. Field Descriptions
      9. 7.6.9  SysREF Registers
        1. Table 33. Field Descriptions
      10. 7.6.10 CHANNEL Divider And VCO Doubler Registers
        1. Table 34. Field Descriptions
      11. 7.6.11 Ramping and Calibration Fields
        1. Table 35. Field Descriptions
      12. 7.6.12 Ramping Registers
        1. Ramp Limits
          1. Table 36. Field Descriptions
        2. Ramping Triggers, Burst Mode, and RAMP0_RST
          1. Table 37. Field Descriptions
        3. Ramping Configuration
          1. Table 38. Field Descriptions
      13. 7.6.13 Readback Registers
        1. Table 39. Field Descriptions
  8. Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 OSCin Configuration
      2. 8.1.2 OSCin Slew Rate
      3. 8.1.3 RF Output Buffer Power Control
      4. 8.1.4 RF Output Buffer Pullup
      5. 8.1.5 Performance Comparison Between 1572 (0x0624) and 3115 (0x0C2B) for Register DBLR_IBIAS_CTRL1 (R25[15:0])
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curve
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
      2. 11.1.2 Development Support
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Community Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

Revision History

Changes from B Revision (March 2018) to C Revision

  • Changed the maximum output frequency from 19 GHz to 20 GHz everywhere in the data sheet. The newly recommended value for the DBLR_IBIAS_CTRL1 (R25[15:0]) extended the output frequency range and improved high frequency performance. The old value (1572) for the DBLR_IBIAS_CTRL1 still supports up to 19-GHz output and specs characterized in the Electrical Characteristics table. The new value (3115) provides a bonus in performance.Go
  • Deleted the recommended bypass capacitor values for Vcc pins 7, 11, 15, 21, 26 and 37, as these capacitor values are not mandatory and the power supply filtering design is up to the user.Go
  • Added test condition "DBLR_IBIAS_CTRL1 = 1572" for POUT, LVCO2X and H1/2, in order to emphasize that these data are taken while DBLR_IBIAS_CTRL1 is set to the old value (1572). With this register set to 3115, these specs can be improved. The details can be found in the applications section.Go
  • Added a new row for VCO doubler output range in EC table with DBLR_IBIAS_CTRL1 set to 3115. The frequency range is extended to 20 GHz.Go
  • Changed all the 'FRAC_ORDER' to 'MASH_ORDER' to avoid confusionGo
  • Added table note for EC table stating that the performance of 1/2 harmonic, output power and noise floor with doubler enabled can be improved by setting DBLR_IBIAS_CTRL1 = 3115. Go
  • Changed the names of timing specs to align with timing diagram: changed tCE to tES, tCS to tDCS, tCH to tCDH, and tCES to tECSGo
  • Changed the names of timing specs to align with timing diagram: changed tES to tCE, tCES to tECS, added tDCS and tCDH, and changed tCS to tCRGo
  • Changed the serial data input timing diagram and corrected the typo for 'SCK'Go
  • Deleted the note 'The CSB transition from high to low must occur when SCK is low' from the serial data input timing diagram, because SPI mode 4 (CPOL = 1, CPHA = 1) is also supported, and SCK is held high when idle in mode 4Go
  • Added note for the serial data input timing diagram to explain the tCE requirement for mode 4 (CPOL = 1, CPHA = 1) of SPI, because the diagram only indicated SPI mode 1 (CPOL = 0, CPHA = 0)Go
  • Changed the serial data readback timing diagramGo
  • Changed the note about MUXout clocking out and emphasized the effect of tCR on the readback data available timeGo
  • Changed the fOUT test conditions in the Closed-Loop Phase Noise at 3.5 GHz graph from: 14 GHz / 2 = 3.5 GHz to: to 14 GHz / 4 = 3.5 GHz Go
  • Added phase noise plot for 16-, 17- and 20-GHz frequency output Go
  • Changed the phase noise plot for 18- and 19-GHz frequency output after changing DBLR_IBIAS_CTRL1 (R25[15:0]) to the new valueGo
  • Changed the Output Power vs Pull-up graph. Output power below 15GHz is shown in "output power across frequency"; output power above 15GHz is shown in "output power vs temperature with doubler". Go
  • Split the Output Power vs Temperature typical performance plot into two plots: Output Power vs Temperature Without Doubler, which goes up to 15 GHz, and Output Power vs Temperature With Doubler that is between 15 GHz and 21 GHz. The data for "without doubler" is unchanged because change of DBLR_IBIAS_CTRL1 does not impact performance under 15 GHz, while the data for "with doubler" plot is taken with DBLR_IBIAS_CTRL1 (R25[15:0]) set to the new value (3115)Go
  • Added Normalized Output Power Across OUTA_PWR With Resistor Pullup graphGo
  • Changed "Vtune" to "Indirect Vtune" when LD_TYPE = 1Go
  • Changed description for LD_TYPE. Go
  • Added description of Indirect Vtune. Go
  • Added description for the 'no assist' mode, mphasized the effect of VCO_SEL, VCO_DACISET_STRT and VCO_CAPCTRL_STRT under 'no assist' mode, and added recommended values for these registersGo
  • Added description for the 'full assist' mode to allow the user to set VCO amplitude and capcode using linear interpolation under certain conditionsGo
  • Changed OUTx_PWR Recommendations for Resistor Pullup table Go
  • Added description for category 3 of SYNC feature stating that FCAL_EN needs to be 1.Go
  • Changed description of MASH_SEED Go
  • Added 10-ms wait time before re-programming register R0 in recommended initial power-up sequence Go
  • Added the General Programming Requirements section based on frequently asked questionsGo
  • Changed register R4 in the register map to: exposed ACAL_CMP_DLY Go
  • Changed the register R20[14] value from 0 to 1 in the full register map to match the R20 register description Go
  • Changed register R25 in the register map; exposed the register 'DBLR_IBIAS_CTRL1.Go
  • Changed the R0[14] register field name in the register map from VCO_PHASE_SYNC_EN to VCO_PHASE_SYNC. to align with the rest of the data sheetGo
  • Added recommended value for register CAL_CLK_DIV when lock time is not of concernGo
  • Changed the typo for register 'VCO_DACISET' in the register map. Bit 0 of this register was not included in the map. The full register map and register description were correctGo
  • Added description to the R4[15:8]: ACAL_CMP_DLY registerGo
  • Deleted the bit description '0: disabled; 1: enabled' for register 'PLL_N'Go
  • Added description to the R60[15:0] LD_DLY registerGo
  • Added description for register R25[15:0]: DBLR_IBIAS_CTRL1 and changed the default register value from 0x0624 to 0x0C2BGo
  • Changed the R31[14] register name from CHDIV_DIV2 to SEG1_EN to align with the naming in the TICS Pro GUIGo
  • Changed the R105[1:0] field name from RAMP_NEXT_TRIG to RAMP1_NEXT_TRIGGo
  • Added application section "Performance Comparison Between 1572 (0x0624) and 3115 (0x0C2B) For Register DBLR_IBIAS_CTRL1 (R25[15:0])" to compare the performance with old and new DBLR_IBIAS_CTRL1 (R25[15:0]) values.Go
  • Added the Bias Levels of Pins tableGo

Changes from A Revision (August 2017) to B Revision

  • Changed all the VCO Gain typical values in the Electrical Characteristics table. This is due to improved measurement methods and NOT a change in the device itselfGo
  • Moved the high-level output voltage parameter VCC – 0.4 value from the MAX column to the MINGo
  • Moved the high-level output current parameter 0.4 value from the MIN column to the MAXGo
  • Changed bulleted text: data is clocked out on MUXout, not SDI pinGo
  • Added comment that OSCin is clocked on rising edges of the signal. and reformatted with bulleted listGo
  • Added description of the state machine clock Go
  • Changed example from: 200 MHz / 232 to: 200 MHz / (232 – 1) Go
  • Changed LD_DLY description in Table 4 and removed duplicated text in the Lock Detect sectionGo
  • Changed name from VCO_AMPCAL to VCO_DACISET_STRT Go
  • Added more programmable settings to Table 5Go
  • Changed VCO Gain tableGo
  • Added that OUTx_PWR states 32 to 47 are redundant and reworded sectionGo
  • Added term "IncludedDivide" for clarity Go
  • Changed Fixed Diagram to show SEG0, SEG1, SEG2, and SEG3 Go
  • Changed included channel divide to IncludedDivide and 2 X SEG0 to 2 X SEG1. Also clarified IncludedDivide calculationsGo
  • Added more description on conditions for phase adustGo
  • Changed text from: (VCO_PHASE_SYNC = 1) to: (VCO_PHASE_SYNC = 0) Go
  • Changed text so the user does not incorrectly assume that MASH_SEED varies from part ot partGo
  • Changed the RAMP_THRESH programming from: 0 to ± 232 to: 0 to ± 233 – 1Go
  • Removed comment that RAMP_TRIG_CAL only applies in automatic ramping modeGo
  • Changed the RAMP_LOW and _HIGH programming from: 0 to ± 231 to: 0 to ± 233 – 1Go
  • Changed description to be in terms of state machine cyclesGo
  • Changed RAMP_MODE to RAMP_MANUAL in the Manual Pin Ramping and Automatic Ramping sectionsGo
  • Added that the RampCLK pin input is reclocked to the phase detector frequencyGo
  • Added that RampDir rising edges should be targeted away from rising edges of RampCLK pinGo
  • Changed programming enumerations for RAMP0_INC and RAMP1_INCGo
  • Changed programming enumerations for RAMP_THRESH, RAMPx_LEN, and RAMP1_INCGo
  • Changed Figure 35Go
  • Changed SysRef descriptionGo
  • Added divide by 2 to figureGo
  • Changed some entries in the table Go
  • Changed fINTERPOLATOR SYSREF setup equation in Table 19Go
  • Changed SysRef delay from: 224 and 225 to: 225 and 226Go
  • Changed "generator" mode to "master" mode. They mean the same thingGo
  • Changed description for SYSREF_DIVGo
  • Changed Figure 37Go
  • Changed wording for repeater mode and master modeGo
  • Changed description of a few of the stepsGo
  • Changed typo in R17 and R19 Go
  • Deleted reference to VCO_SEL_STRT_EN. This is always 1Go
  • Added VCO_SEL_STRT_EN reference. This is always 1Go
  • Changed the enumerations 0-3 and added content to the INPIN_LVL field description Go
  • Added Divide by 1' to SYSREF_DIV_PRE register description. Also fixed the name misspellingGo
  • Deleted redundant formula for Fout and also clarified SYSREF_DIV starts at 4 and counts by 2Go
  • Deleted reference to VCO_CAPCTRL_EN, which is always 1, and clarifiedGo
  • Changed text from: fMAX to: fHIGHGo
  • Changed text from: RAMP_LIMIT_LOW=232 - (fLOW - fVCO) / fPD × 16777216 to: RAMP_LIMIT_LOW=233 - 16777216 x (fVCO - fLOW) / fPDGo
  • Removed the OSCin Configuration table and added content to the OSCin Configuration sectionGo
  • Changed pin 27 recommendation from 10 µF to 1 µF in Figure 62Go

Changes from * Revision (June 2017) to A Revision

  • Changed "SDA" pin name mispelled. Should be "SDI". Also fixed in timing diagrams. Also added CE Pin Go
  • Clarified that output power assumes that load is matched and losses are de-embeddedGo
  • Swapped SDI and SCK in diagram Go
  • Added section on fine tune adjustments Go
  • Removed RAMP0_FL from register mapGo
  • Clarified MASH_RESET_N. 0 = RESET (integer mode), 1 = Fractional mode Go
  • Changed OUT_ISEL to OUTI_SET Go
  • Added section for input register descriptions Go
  • Fixed TYPO table to match main register map.Go
  • Corrected RAMP_BURST_TRIG description to match other place in data sheetGo
  • Removed duplicate error in R101[2] Go
  • Changed RAMP1_INC from RAMP0 to RAMP1Go
  • Clarified that the delay was in state machine cyclesGo
  • Fixed pin names in schematic Go