SNVSB99C October   2019  – November 2020 LMR33640

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Characteristics
    7. 7.7 System Characteristics
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Power-Good Flag Output
      2. 8.3.2 Enable and Start-up
      3. 8.3.3 Current Limit and Short Circuit
      4. 8.3.4 Undervoltage Lockout and Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Auto Mode
      2. 8.4.2 Dropout
      3. 8.4.3 Minimum Switch On-Time
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1  Custom Design With WEBENCH® Tools
        2. 9.2.2.2  Setting the Output Voltage
        3. 9.2.2.3  Inductor Selection
        4. 9.2.2.4  Output Capacitor Selection
        5. 9.2.2.5  Input Capacitor Selection
        6. 9.2.2.6  CBOOT
        7. 9.2.2.7  VCC
        8. 9.2.2.8  CFF Selection
        9. 9.2.2.9  External UVLO
        10. 9.2.2.10 Maximum Ambient Temperature
      3. 9.2.3 Application Curves
    3. 9.3 What to Do and What Not to Do
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Ground and Thermal Considerations
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Development Support
        1. 12.1.1.1 Custom Design With WEBENCH® Tools
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Support Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9.2.3 Application Curves

Unless otherwise specified, the following conditions apply: VIN = 12 V, TA = 25°C. Figure 9-21 shows the circuit with the appropriate BOM from Table 9-3.

GUID-7830F7AB-136D-4225-B6CC-D63FFE3794AE-low.gif
VOUT = 5 V ƒSW = 400 kHz
Figure 9-5 Efficiency
GUID-BDEF9EFD-CAC8-40E7-8C66-3E8816677398-low.gif
VOUT = 5 V ƒSW = 1000 kHz
Figure 9-7 Efficiency
GUID-1716B176-A2C2-4A4D-AFDF-45AF3C3D73A2-low.gif
VOUT = 5 V
Figure 9-9 Line and Load Regulation
GUID-1C574D43-ED7C-4CB4-9C74-FB5DE78D7BE0-low.gif
VOUT = 3.3 V ƒSW = 400 kHz
Figure 9-6 Efficiency
GUID-EA3EE741-7FBA-4085-A9DC-7B67584C889C-low.gif
VOUT = 3.3 V ƒSW = 1000 kHz
Figure 9-8 Efficiency
GUID-C7E83BFB-886E-4A08-8528-9983A254D892-low.gif
VOUT = 3.3 V
Figure 9-10 Line and Load Regulation
GUID-1AE318F9-C8F1-4E08-90C0-1153663E3CF2-low.gif
VIN = 12 V VOUT = 5 V
ƒSW = 400 kHz IOUT = 0 A to 4 A
Figure 9-11 Load Transient
GUID-D065FD13-3468-48B3-B091-B9C1B4D50BF6-low.gif
VIN = 12 V VOUT = 5 V
ƒSW = 400 kHz IOUT = 1 A to 4 A
Figure 9-13 Load Transient
GUID-0294CBE2-0C1D-419A-9B5B-30DC934133AC-low.gif
VIN = 12 V VOUT = 5 V
ƒSW = 1000 kHz IOUT = 0 A to 4 A
Figure 9-15 Load Transient
GUID-10C201ED-D57B-4F95-8ED8-E1EF729B4846-low.gif
VIN = 12 V VOUT = 3.3 V
ƒSW = 400 kHz IOUT = 0 A to 4 A
Figure 9-12 Load Transient
GUID-286D4968-A259-4FEE-A77F-AAA34DB99C19-low.gif
VIN = 12 V VOUT = 3.3 V
ƒSW = 400 kHz IOUT = 1 A to 4 A
Figure 9-14 Load Transient
GUID-7308CFA7-C49B-4E19-B544-79B779D2902D-low.gif
VIN = 12 V VOUT = 3.3 V
ƒSW = 1000 kHz IOUT = 0 A to 4 A
Figure 9-16 Load Transient
GUID-DDE8B119-3746-4755-82AA-85B42C06B685-low.gif
VIN = 12 V VOUT = 5 V
ƒSW = 1000 kHz IOUT = 1 A to 4 A
Figure 9-17 Load Transient
GUID-B0339DEF-3F71-4046-AA95-818BC1A9EE5D-low.gif
ƒSW = 400 kHz VOUT = 5 V
Figure 9-19 Load Transient
GUID-F547045F-C5AF-4F94-A444-D0A54A6835C9-low.gif
VIN = 12 V VOUT = 3.3 V
ƒSW = 1000 kHz IOUT = 1 A to 4 A
Figure 9-18 Load Transient
GUID-8BBF3D8F-A7F5-45EC-A41A-E3A2D82ECEEC-low.gif
ƒSW = 1000 kHz VOUT = 5 V
Figure 9-20 Load Transient
GUID-10219432-3939-46B7-8D90-8CBE0FFA1229-low.gifFigure 9-21 Circuit for Application Curves
Table 9-3 BOM for Typical Application Curves
VOUT(1)FREQUENCYRFBBCOUTCIN + CHFLU1
3.3 V400 kHz43.3 kΩ3 × 22 µF1 × 10 µF + 1 × 220 nF6.8 µH, 18 mΩLMR33640ADDA
5 V400 kHz24.9 kΩ3 × 22 µF1 × 10 µF + 1 × 220 nF6.8 µH, 18 mΩLMR33640ADDA
3.3 V1000 kHz43.3 kΩ3 × 22 µF1 × 10 µF + 1 × 220 nF3.3 µH, 16 mΩLMR33640DDDA
5 V1000 kHz24.9 kΩ3 × 22 µF1 × 10 µF + 1 × 220 nF3.3 µH, 16 mΩLMR33640DDDA
(1) The values in this table were selected to enhance certain performance criteria and may not represent typical values.