SNVSC22B October   2023  – June 2024 LM51772

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 Handling Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements
    7. 5.7 Typical Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Buck-Boost Control Scheme
        1. 7.3.1.1 Buck Mode
        2. 7.3.1.2 Boost Mode
        3. 7.3.1.3 Buck-Boost Mode
      2. 7.3.2  Power Save Mode
      3. 7.3.3  Programmable Conduction Mode PCM
      4. 7.3.4  Reference System
        1. 7.3.4.1 VIO LDO and nRST-PIN
      5. 7.3.5  Supply Voltage Selection – VSMART Switch and Selection Logic
      6. 7.3.6  Enable and Undervoltage Lockout
        1. 7.3.6.1 UVLO
        2. 7.3.6.2 VDET Comparator
      7. 7.3.7  Internal VCC Regulators
        1. 7.3.7.1 VCC1 Regulator
        2. 7.3.7.2 VCC2 Regulator
      8. 7.3.8  Error Amplifier and Control
        1. 7.3.8.1 Output Voltage Regulation
        2. 7.3.8.2 Output Voltage Feedback
        3. 7.3.8.3 Voltage Regulation Loop
        4. 7.3.8.4 Dynamic Voltage Scaling
      9. 7.3.9  Output Voltage Discharge
      10. 7.3.10 Peak Current Sensor
      11. 7.3.11 Short Circuit - Hiccup Protection
      12. 7.3.12 Current Monitor/Limiter
        1. 7.3.12.1 Overview
        2. 7.3.12.2 Output Current Limitation
        3. 7.3.12.3 Output Current Monitor
      13. 7.3.13 Oscillator Frequency Selection
      14. 7.3.14 Frequency Synchronization
      15. 7.3.15 Output Voltage Tracking
        1. 7.3.15.1 Analog Voltage Tracking
        2. 7.3.15.2 Digital Voltage Tracking
      16. 7.3.16 Slope Compensation
      17. 7.3.17 Configurable Soft Start
      18. 7.3.18 Drive Pin
      19. 7.3.19 Dual Random Spread Spectrum – DRSS
      20. 7.3.20 Gate Driver
      21. 7.3.21 Cable Drop Compensation (CDC)
      22. 7.3.22 CFG-pin and R2D Interface
      23. 7.3.23 Advanced Monitoring Features
        1. 7.3.23.1  Overview
        2. 7.3.23.2  BUSY
        3. 7.3.23.3  OFF
        4. 7.3.23.4  VOUT
        5. 7.3.23.5  IOUT
        6. 7.3.23.6  INPUT
        7. 7.3.23.7  TEMPERATURE
        8. 7.3.23.8  CML
        9. 7.3.23.9  OTHER
        10. 7.3.23.10 ILIM_OP
        11. 7.3.23.11 nFLT/nINT Pin Output
        12. 7.3.23.12 Status Byte
      24. 7.3.24 Protection Features
        1. 7.3.24.1  Thermal Shutdown (TSD)
        2. 7.3.24.2  Over Current Protection
        3. 7.3.24.3  Output Over Voltage Protection 1 (OVP1)
        4. 7.3.24.4  Output Over Voltage Protection 2 (OVP2)
        5. 7.3.24.5  Input Voltage Protection (IVP)
        6. 7.3.24.6  Input Voltage Regulation (IVR)
        7. 7.3.24.7  Power Good
        8. 7.3.24.8  Boot-Strap Under Voltage Protection
        9. 7.3.24.9  Boot-strap Over Voltage Clamp
        10. 7.3.24.10 CRC - CHECK
    4. 7.4 Device Functional Modes
      1. 7.4.1 Overview
      2. 7.4.2 Logic State Description
    5. 7.5 Programming
      1. 7.5.1 I2C Bus Operation
      2. 7.5.2 Clock Stretching
      3. 7.5.3 Data Transfer Formats
      4. 7.5.4 Single READ from a Defined Register Address
      5. 7.5.5 Sequential READ Starting from a Defined Register Address
      6. 7.5.6 Single WRITE to a Defined Register Address
      7. 7.5.7 Sequential WRITE Starting at a Defined Register Address
  9. 8 LM51772 Registers
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1  Custom Design with WEBENCH Tools
        2. 9.2.2.2  Frequency
        3. 9.2.2.3  Feedback Divider
        4. 9.2.2.4  Inductor and Current Sense Resistor Selection
        5. 9.2.2.5  Output Capacitor
        6. 9.2.2.6  Input Capacitor
        7. 9.2.2.7  Slope Compensation
        8. 9.2.2.8  UVLO Divider
        9. 9.2.2.9  Soft-Start Capacitor
        10. 9.2.2.10 MOSFETs QH1 and QL1
        11. 9.2.2.11 MOSFETs QH2 and QL2
        12. 9.2.2.12 Loop Compensation
        13. 9.2.2.13 External Component Selection
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
        1. 9.4.1.1 Power Stage Layout
        2. 9.4.1.2 Gate Driver Layout
        3. 9.4.1.3 Controller Layout
      2. 9.4.2 Layout Example
    5. 9.5 USB-PD Source with Power Path
    6. 9.6 Parallel (Multiphase) Operation
    7. 9.7 Constant Current LED Driver
    8. 9.8 Wireless Charging Supply
    9. 9.9 Bi-Directional Power Backup
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

7.3.18 Drive Pin

The device features a high voltage drive pin (DRV1) to support an input or output disconnect FET. This in can be also used as a driver for a charge pump output to do a reverse polarity protection using a external n-channel FET. The supply for this pin can be selected by R2D and I2C configurations.


LM51772 Functional Block Diagram - DRV pin

Figure 7-29 Functional Block Diagram - DRV pin

The following configurations are possible with to support with the DRV1 pin:

  1. Open drain output.
  2. High Voltage Push-pull supplied by VOUT
  3. High Voltage Push-pull supplied by VBIAS
  4. CP drive pin supplied by the VCC2

The sequencing of the DRV pin is depending on the setting an given by the register Table 8-18