SNVSCG7 November   2024 LM5190

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 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1  Input Voltage Range (VIN)
      2. 6.3.2  High-Voltage Bias Supply Regulator (VCC, BIAS)
      3. 6.3.3  Precision Enable (EN)
      4. 6.3.4  Power-Good Monitor (PGOOD)
      5. 6.3.5  Switching Frequency (RT)
      6. 6.3.6  Low Dropout Mode
      7. 6.3.7  Dual Random Spread Spectrum (DRSS)
      8. 6.3.8  Soft Start
      9. 6.3.9  Output Voltage Setpoint (FB)
      10. 6.3.10 Minimum Controllable On Time
      11. 6.3.11 Inductor Current Sense (ISNS+, VOUT)
      12. 6.3.12 Voltage Loop Error Amplifier
      13. 6.3.13 Current Monitor, Programmable Current Limit, and Current Loop Error Amplifier (IMON/ILIM, ISET)
      14. 6.3.14 Dual Loop Architecture
      15. 6.3.15 PWM Comparator
      16. 6.3.16 Slope Compensation
      17. 6.3.17 Hiccup Mode Current Limiting
      18. 6.3.18 High-Side and Low-Side Gate Drivers (HO, LO)
    4. 6.4 Device Functional Modes
      1. 6.4.1 Sleep Mode
      2. 6.4.2 Forced PWM Mode and Synchronization (FPWM/SYNC)
      3. 6.4.3 Thermal Shutdown
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Power Train Components
        1. 7.1.1.1 Buck Inductor
        2. 7.1.1.2 Output Capacitors
        3. 7.1.1.3 Input Capacitors
        4. 7.1.1.4 Power MOSFETs
        5. 7.1.1.5 EMI Filter
      2. 7.1.2 Error Amplifier and Compensation
    2. 7.2 Typical Applications
      1. 7.2.1 High Efficiency 400kHz CC-CV Regulator
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
          1. 7.2.1.2.1 Buck Inductor
          2. 7.2.1.2.2 Current-Sense Resistance
          3. 7.2.1.2.3 Output Capacitors
          4. 7.2.1.2.4 Input Capacitors
          5. 7.2.1.2.5 Frequency Set Resistor
          6. 7.2.1.2.6 Feedback Resistors
        3. 7.2.1.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
        1. 7.4.1.1 Power Stage Layout
        2. 7.4.1.2 Gate-Drive Layout
        3. 7.4.1.3 PWM Controller Layout
        4. 7.4.1.4 Thermal Design and Layout
        5. 7.4.1.5 Ground Plane Design
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
        1. 8.2.1.1 PCB Layout Resources
        2. 8.2.1.2 Thermal Design Resources
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

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

6.3.9 Output Voltage Setpoint (FB)

The LM5190 regulator output can be independently configured for one of two fixed output voltages without external feedback resistors, or adjusted to a desired voltage using an external resistor divider. Set the output to 5V by connecting FB to AGND during initial power on. Set the output to 12V by connecting FB to VCC during initial power on. See Table 6-1.

Table 6-1 Output Regulation Targets
FB SELECTION VOUT SETPOINT
FB = VCC 12V
FB = AGND 5V
FB = FB resistors Adjustable

The configuration settings are latched and cannot be changed until the LM5190 is powered down (with the VCC voltage decreasing below the falling UVLO threshold) and then powered up again (VCC rises above 4.8V typical). Alternatively, the output regulation target can be adjusted during operation by connecting external feedback divider resistors whose parallel resistance is greater than 5.0kΩ (see Equation 3).

Equation 3. 5   kΩ < R F B T × R F B B R F B T + R F B B

The output voltage adjustment range is between 0.8V and 79V. The regulation voltage at FB is 0.8V (VREF-V). Use Equation 4 to calculate the top and bottom feedback resistors, designated as RFBT and RFBB, respectively.

Equation 4. R F B T = ( V O U T V R E F - 1 ) × R F B B

If low-IQ operation is required, take care when selecting the external feedback resistors. The current consumption of the external divider adds to the LM5190 sleep current (15µA typical). The divider current reflected to VIN is scaled by the ratio of VOUT / VIN.