SNVSAP9A March   2017  – February 2018 LM25141-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      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 Switching Characteristics
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  High Voltage Start-Up Regulator
      2. 7.3.2  VCC Regulator
      3. 7.3.3  Oscillator
      4. 7.3.4  Synchronization
      5. 7.3.5  Frequency Dithering (Spread Spectrum)
      6. 7.3.6  Enable
      7. 7.3.7  Power Good
      8. 7.3.8  Output Voltage
        1. 7.3.8.1 Minimum Output Voltage Adjustment
      9. 7.3.9  Current Sense
      10. 7.3.10 DCR Current Sensing
      11. 7.3.11 Error Amplifier and PWM Comparator
      12. 7.3.12 Slope Compensation
      13. 7.3.13 Hiccup Mode Current Limiting
      14. 7.3.14 Standby Mode
      15. 7.3.15 Soft Start
      16. 7.3.16 Diode Emulation
      17. 7.3.17 High- and Low-Side Drivers
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Custom Design With WEBENCH® Tools
        2. 8.2.2.2 Inductor Calculation
        3. 8.2.2.3 Current Sense Resistor
        4. 8.2.2.4 Output Capacitor
        5. 8.2.2.5 Input Filter
          1. 8.2.2.5.1 EMI Filter Design
          2. 8.2.2.5.2 MOSFET Selection
          3. 8.2.2.5.3 Driver Slew Rate Control
          4. 8.2.2.5.4 Frequency Dithering
        6. 8.2.2.6 Control Loop
          1. 8.2.2.6.1 Feedback Compensator
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Layout Procedure
    2. 10.2 Layout Examples
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
        1. 11.1.1.1 Custom Design With WEBENCH® Tools
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
        1. 11.2.1.1 PCB Layout Resources
        2. 11.2.1.2 Thermal Design Resources
    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

3 Description

The LM25141-Q1 is a synchronous buck controller, intended for high-voltage, wide-VIN, step-down regulator applications. The control method is peak current-mode control. Current-mode control provides inherent line feed-forward, cycle-by-cycle current limiting, and ease of loop compensation. The LM25141-Q1 features slew rate control to simplify the compliance with CISPR and automotive EMI requirements.

The LM25141-Q1 has two selectable switching frequencies: 2.2 MHz and 440 kHz. Gate drivers with slew rate control can be adjusted to reduce EMI.

In light or no-load conditions, the LM25141-Q1 operates in skip cycle mode for improved low power efficiency. The LM25141-Q1 has a high-voltage bias regulator with automatic switch-over to an external bias to reduce the IQ current from VIN. Additional features include frequency synchronization, cycle-by-cycle current limit, hiccup-mode fault protection for sustained overload, and power-good output.

Device Information(1)

PART NUMBERPACKAGEBODY SIZE (NOM)
LM25141-Q1 VQFN (24) 4.00 mm × 4.00 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.