SNVSBF0C September   2019  – November 2025 LMR36520

PRODUCTION DATA  

  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
    6. 6.6 Timing Requirements
    7. 6.7 Switching Characteristics
    8. 6.8 System Characteristics
    9. 6.9 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Power-Good Flag Output
      2. 7.3.2 Enable and Start-Up
      3. 7.3.3 Current Limit and Short Circuit
      4. 7.3.4 Undervoltage Lockout and Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Auto Mode
      2. 7.4.2 Forced PWM Operation
      3. 7.4.3 Dropout
      4. 7.4.4 Minimum Switch On-Time
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design 1: Low Power 24-V, 2-A Buck Converter
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1  Choosing the Switching Frequency
          2. 8.2.1.2.2  Setting the Output Voltage
          3. 8.2.1.2.3  Inductor Selection
          4. 8.2.1.2.4  Output Capacitor Selection
          5. 8.2.1.2.5  Input Capacitor Selection
          6. 8.2.1.2.6  CBOOT
          7. 8.2.1.2.7  VCC
          8. 8.2.1.2.8  CFF Selection
          9. 8.2.1.2.9  External UVLO
          10. 8.2.1.2.10 Maximum Ambient Temperature
        3. 8.2.1.3 Application Curves
    3. 8.3 Best Design Practices
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
        1. 8.5.1.1 Ground and Thermal Considerations
      2. 8.5.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Development Support
    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

8.2.1.3 Application Curves

Unless otherwise specified, the following conditions apply: VIN = 24 V, TA = 25°C. Figure 8-20 shows the circuit with the appropriate BOM from Table 8-4.

LMR36520 Efficiency
LMR36520A VOUT = 3.3 V 400 kHz
Figure 8-4 Efficiency
LMR36520 Efficiency
LMR36520A VOUT = 5 V 400 kHz
Figure 8-6 Efficiency
LMR36520 Efficiency
LMR36520A VOUT = 12 V 400 kHz
Figure 8-8 Efficiency
LMR36520 Dropout Characteristic
VOUT = 5 V 400 kHz
Figure 8-10 Dropout Characteristic
LMR36520 Input Supply Current
VOUT = 3.3 VIOUT = 0 A
Figure 8-12 Input Supply Current
LMR36520 Enable Start-Up Waveform
VIN = 24 VVOUT = 3.3 VILOAD = 2 A
Figure 8-14 Enable Start-Up Waveform
LMR36520 Load Transient
VOUT = 3.3 V400 kHzILOAD = 0.5 A - 2 A
Slew Rate = 1 A/µs
Figure 8-16 Load Transient
LMR36520 Output Ripple at No load
VIN = 24 VVOUT = 5 VILOAD = 0 A
Figure 8-18 Output Ripple at No load
LMR36520 Load Regulation
LMR36520A VOUT = 3.3 V 400 kHz
Figure 8-5 Load Regulation
LMR36520 Load Regulation
LMR36520A VOUT = 5 V 400 kHz
Figure 8-7 Load Regulation
LMR36520 Load Regulation
LMR36520A VOUT = 12 V 400 kHz
Figure 8-9 Load Regulation
LMR36520 Dropout Characteristic
VOUT = 12 V 400 kHz
Figure 8-11 Dropout Characteristic
LMR36520 Input Supply Current versus Load Current
VOUT = 3.3 VRFBT = 100 kΩ
Figure 8-13 Input Supply Current versus Load Current
LMR36520 Enable Shutdown Waveform
VIN = 24 VVOUT = 3.3 VILOAD = 2 A
Figure 8-15 Enable Shutdown Waveform
LMR36520 Load Transient
VOUT = 5 V400 kHzILOAD = 0.5 A - 2 A
Slew Rate = 1 A/µs
Figure 8-17 Load Transient
LMR36520 Output Ripple at 1 A
VIN = 24 VVOUT = 5 VILOAD = 1 A
Figure 8-19 Output Ripple at 1 A
LMR36520 Circuit for Typical Application CurvesFigure 8-20 Circuit for Typical Application Curves
Table 8-4 BOM for Typical Application Curves
VOUTFREQUENCYLCOUTRFBTRFBBCFFIC
3.3 V400 kHz6.8 µH, 29.45 mΩ3 x 22 µF, 25V46.4 kΩ20.0 kΩNoneLMR36520A
5 V400 kHz10 µH, 29.82 mΩ2 x 22 µF, 25V34.0 kΩ + 46.4 kΩ20.0 kΩNoneLMR36520A
12 V400 kHz33 µH, 57 mΩ3 x 22 µF, 25V100 kΩ9.09 kΩNoneLMR36520A