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

8.2.3 Application Curves

The following characteristics apply to the circuit shown in Figure 8-1. These parameters are not tested and represent typical performance only. Unless otherwise stated, the following conditions apply: VIN = 12V, TA = 25°C.

LMR60450-Q1 Efficiency - Auto Mode
VOUT = 3.3V Fsw = 2MHz Mode = Auto
Figure 8-2 Efficiency - Auto Mode
LMR60450-Q1 Efficiency - Auto Mode
VOUT = 3.3V Fsw = 400kHz Mode = Auto
Figure 8-4 Efficiency - Auto Mode
LMR60450-Q1 Load and Line Regulation - Auto Mode
VOUT = 3.3V Fsw = 2MHz Mode = Auto
Figure 8-6 Load and Line Regulation - Auto Mode
LMR60450-Q1 Load and Line Regulation - Auto Mode
VOUT = 3.3V Fsw = 400kHz Mode = Auto
Figure 8-8 Load and Line Regulation - Auto Mode
LMR60450-Q1 Dropout Curve
VOUT = 3.3V Fsw = 2MHz Mode = Auto
Figure 8-10 Dropout Curve
LMR60450-Q1 Load Transient
VIN = 12V VOUT = 3.3V Mode = AUTO
Fsw = 2MHz IOUT = 0A to 5A
Figure 8-12 Load Transient
LMR60450-Q1 Steady-State Switching Waveform and Output Voltage Ripple
VIN = 12V VOUT = 3.3V Mode = AUTO
Fsw = 2MHz IOUT = 25mA
Figure 8-14 Steady-State Switching Waveform and Output Voltage Ripple
LMR60450-Q1 Enable Start-Up and Shutdown With 50mA Load
VIN = 12V VOUT = 3.3V Mode = AUTO
Fsw = 2MHz IOUT = 25mA
Figure 8-16 Enable Start-Up and Shutdown With 50mA Load
LMR60450-Q1 Short-Circuit Behavior
VIN = 12V VOUT = 3.3V Mode = FPWM
Fsw = 2MHz IOUT = 0A
Figure 8-18 Short-Circuit Behavior
LMR60450-Q1 Conducted EMI vs CISPR 25 Limits (Pink: Peak Signal, Green: Average Signal)
VIN = 12V VOUT = 5V Fsw = 400kHz
IOUT = 6A
Figure 8-20 Conducted EMI vs CISPR 25 Limits (Pink: Peak Signal, Green: Average Signal)
LMR60450-Q1 Efficiency - FPWM Mode
VOUT = 3.3V Fsw = 2MHz Mode = FPWM
Figure 8-3 Efficiency - FPWM Mode
LMR60450-Q1 Efficiency - FPWM Mode
VOUT = 3.3V Fsw = 400kHz Mode = FPWM
Figure 8-5 Efficiency - FPWM Mode
LMR60450-Q1 Load and Line Regulation - FPWM Mode
VOUT = 3.3V Fsw = 2MHz Mode = FPWM
Figure 8-7 Load and Line Regulation - FPWM Mode
LMR60450-Q1 Load and Line Regulation - FPWM Mode
VOUT = 3.3V Fsw = 400kHz Mode = FPWM
Figure 8-9 Load and Line Regulation - FPWM Mode
LMR60450-Q1 Output Current versus Maximum Ambient Temperature
VOUT = 3.3V Fsw = 400kHz LMR60460QEVM, No air flow
Figure 8-11 Output Current versus Maximum Ambient Temperature
LMR60450-Q1 Load Transient
VIN = 12V VOUT = 3.3V Mode = FPWM
Fsw = 2MHz IOUT = 0A to 5A
Figure 8-13 Load Transient
LMR60450-Q1 Steady-State Switching Waveform and Output Voltage Ripple
VIN = 12V VOUT = 3.3V Mode = FPWM
Fsw = 2MHz IOUT = 5A
Figure 8-15 Steady-State Switching Waveform and Output Voltage Ripple
LMR60450-Q1 Enable Start-Up and Shutdown With 5A Load
VIN = 12V VOUT = 3.3V Mode = FPWM
Fsw = 2MHz IOUT = 5A
Figure 8-17 Enable Start-Up and Shutdown With 5A Load
LMR60450-Q1 Conducted EMI vs CISPR 25 Limits (Pink: Peak Signal, Green: Average Signal)
VIN = 12V VOUT = 3.3V Fsw = 2MHz
IOUT = 6A
Figure 8-19 Conducted EMI vs CISPR 25 Limits (Pink: Peak Signal, Green: Average Signal)
LMR60450-Q1 Recommended input EMI filterFigure 8-21 Recommended input EMI filter