SNAS895 September   2025 LMR60450-Q1

ADVANCE INFORMATION  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 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
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Enable and Undervoltage Lockout (UVLO)
      2. 7.3.2 Soft Start and Recovery from Dropout
      3. 7.3.3 Frequency Selection With RT
      4. 7.3.4 MODE/SYNC Pin Control
      5. 7.3.5 Output Voltage Selection
      6. 7.3.6 Current Limit
      7. 7.3.7 Hiccup Mode
      8. 7.3.8 Power-Good Function
      9. 7.3.9 Spread Spectrum
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown
      2. 7.4.2 Active Mode
        1. 7.4.2.1 Auto Mode Operation
        2. 7.4.2.2 Continuous Conduction Mode (CCM)
        3. 7.4.2.3 FPWM Operation
        4. 7.4.2.4 Minimum On-Time
        5. 7.4.2.5 Dropout
  9. 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 Switching Frequency Selection
        2. 8.2.2.2 Inductor Selection
        3. 8.2.2.3 Output Capacitor Selection
        4. 8.2.2.4 Input Capacitor Selection
        5. 8.2.2.5 Bootstrap Capacitor (CBOOT) Selection
        6. 8.2.2.6 FB Voltage Divider for Adjustable Output Voltages
          1. 8.2.2.6.1 Feedforward Capacitor (CFF) Selection
        7. 8.2.2.7 RPG - PG Pullup Resistor
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
        1. 8.4.1.1 Ground and Thermal Plane Considerations
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Third-Party Products Disclaimer
      2. 9.1.2 Device Nomenclature
    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
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information
    1. 11.1 Tape and Reel Information

3 Description

The LMR60450-Q1 is a 3V to 36V (42V transient), 5Aautomotive-grade synchronous buck converter. The LMR60450-Q1 is available in an ultra compact 2.5mm × 2mm QFN-9 package with wettable flanks, that helps minimize inductance and achieve low EMI performance to facilitate qualification of automotive and other noise-sensitive designs.

All device variants are capable of output voltages ranging from 1V to 20V in adjustable output configuration. Each variant is also capable of delivering a fixed output voltage by connecting the output voltage node directly to the feedback pin. The Device Comparison Table provides details on the fixed output voltage options. The current-mode control architecture with 30ns minimum on-time allows high conversion ratios at high frequencies, easy loop compensation, fast transient response, and excellent load and line regulation.

Open drain power-good output facilitates power sequencing requirements. The MODE/SYNC pin of the LMR60450-Q1 allows the user to select between forced pulse width modulation (FPWM), auto mode, or external synchronization mode of operation.

The LMR60450-Q1 is designed to offer reduced output capacitance leading to compact PCB layout and system cost savings. The LMR60450-Q1 is a part of a family of pin-compatible devices ranging in current levels from 0.6A to 6A.

Package Information
PART NUMBER PACKAGE(1) PACKAGE SIZE(2)
LMR60450-Q1 VBC (WQFN-FCRLF, 9) 2.5mm × 2mm
(1) For more information, see Section 11.
(2) The package size (length × width) is a nominal value and includes pins, where applicable.
LMR60450-Q1 Example Schematic - 2.2MHz 3.3V Fixed OutputExample Schematic - 2.2MHz 3.3V Fixed Output
LMR60450-Q1 EVM Layout - 2.2MHz 3.3V Fixed OutputEVM Layout - 2.2MHz 3.3V Fixed Output