SNAS680E December   2015  – August 2022 LMX2582

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Functional Description
      1. 7.3.1  Input Signal
      2. 7.3.2  Input Signal Path
      3. 7.3.3  PLL Phase Detector and Charge Pump
      4. 7.3.4  N Divider and Fractional Circuitry
      5. 7.3.5  Voltage Controlled Oscillator
      6. 7.3.6  VCO Calibration
      7. 7.3.7  Channel Divider
      8. 7.3.8  Output Distribution
      9. 7.3.9  Output Buffer
      10. 7.3.10 Phase Adjust
    4. 7.4 Device Functional Modes
      1. 7.4.1 Power Down
      2. 7.4.2 Lock Detect
      3. 7.4.3 Register Readback
    5. 7.5 Programming
      1. 7.5.1 Recommended Initial Power on Programming Sequence
      2. 7.5.2 Recommended Sequence for Changing Frequencies
    6. 7.6 Register Maps
      1. 7.6.1 LMX2582 Register Map – Default Values
        1. 7.6.1.1 Register Descriptions
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1  Optimization of Spurs
        1. 8.1.1.1 Understanding Spurs by Offsets
        2. 8.1.1.2 Spur Mitigation Techniques
      2. 8.1.2  Configuring the Input Signal Path
        1. 8.1.2.1 Input Signal Noise Scaling
      3. 8.1.3  Input Pin Configuration
      4. 8.1.4  Using the OSCin Doubler
      5. 8.1.5  Using the Input Signal Path Components
        1. 8.1.5.1 Moving Phase Detector Frequency
        2. 8.1.5.2 Multiplying and Dividing by the Same Value
      6. 8.1.6  Designing for Output Power
      7. 8.1.7  Current Consumption Management
      8. 8.1.8  Decreasing Lock Time
      9. 8.1.9  Modeling and Understanding PLL FOM and Flicker Noise
      10. 8.1.10 External Loop Filter
    2. 8.2 Typical Application
      1. 8.2.1 Design for Low Jitter
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curve
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  9. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Development Support
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  10. 10Mechanical, Packaging, and Orderable Information

7.3.5 Voltage Controlled Oscillator

The voltage controlled oscillator (VCO) is fully integrated. The frequency range of the VCO is from 3.55 to 7.1 GHz so it covers one octave. Channel dividers allow the generation of all other lower frequencies. The VCO-doubler allow the generation of all other higher frequencies. The output frequency of the VCO is inverse proportional to the DC voltage present at the tuning voltage point on pin Vtune. The tuning range is 0 V to 2.5 V. 0 V generates the maximum frequency and 2.5 V generates the minimum frequency. This VCO requires a calibration procedure for each frequency selected to lock on. Each VCO calibration will force the tuning voltage to mid value and calibrate the VCO circuit. Any frequency setting in fast calibration occurs in the range of Vtune pin 0 V to 2.5 V. The VCO is designed to remained locked over the entire temperature range the device can support. Table 7-3 shows the VCO gain as a function of frequency.

Table 7-3 Typical kVCO
VCO FREQUENCY (MHz)kVCO (MHz/V)
370028
420030
470033
520036
570041
620047
680051