SNVS085X July   2000  – December 2017 LM3478

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical High Efficiency Step-Up (Boost) Converter
  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 - LM3478
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 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 Overvoltage Protection
      2. 7.3.2 Slope Compensation Ramp
      3. 7.3.3 Frequency Adjust/Shutdown
      4. 7.3.4 Short-Circuit Protection
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Typical High Efficiency Step-Up (Boost) Converter
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1  Custom Design with WEBENCH Tools
          2. 8.2.1.2.2  Power Inductor Selection
          3. 8.2.1.2.3  Programming the Output Voltage
          4. 8.2.1.2.4  Setting the Current Limit
          5. 8.2.1.2.5  Current Limit with External Slope Compensation
          6. 8.2.1.2.6  Power Diode Selection
          7. 8.2.1.2.7  Power MOSFET Selection
          8. 8.2.1.2.8  Input Capacitor Selection
          9. 8.2.1.2.9  Output Capacitor Selection
          10. 8.2.1.2.10 Compensation
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Typical SEPIC Converter
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
          1. 8.2.2.2.1 Power MOSFET Selection
          2. 8.2.2.2.2 Power Diode Selection
          3. 8.2.2.2.3 Selection of Inductors L1 and L2
          4. 8.2.2.2.4 Sense Resistor Selection
          5. 8.2.2.2.5 Sepic Capacitor Selection
          6. 8.2.2.2.6 Input Capacitor Selection
          7. 8.2.2.2.7 Output Capacitor Selection
        3. 8.2.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Custom Design with WEBENCH Tools
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Documentation Support
      1. 11.3.1 Related Documentation
    4. 11.4 Related Links
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

6.6 Typical Characteristics

Unless otherwise specified, VIN = 12V, TJ = 25°C.
LM3478 10135503.png
Figure 1. IQ vs Input Voltage (Shutdown)
LM3478 10135535.png
Figure 3. ISupply vs VIN (Switching)
LM3478 10135554.png
Figure 5. Frequency vs Temperature
LM3478 10135545.png
Figure 7. Current Sense Threshold vs Input Voltage
LM3478 10135559.png
Figure 9. Efficiency vs Load Current (3.3-V Input and 12-V Output)
LM3478 10135560.png
Figure 11. Efficiency vs Load Current (9-V Input and 12-V Output)
LM3478 10135555.png
Figure 13. Error Amplifier Gain
LM3478 10135536.png
Figure 15. COMP Pin Source Current vs Temperature
LM3478 10135551.png
Figure 17. Compensation Ramp vs Compensation Resistor
LM3478 10135594.png
Figure 19. Duty Cycle vs Current Sense Voltage
LM3478 10135534.png
Figure 2. ISupply vs Input Voltage (Non-Switching)
LM3478 10135504.png
Figure 4. Switching Frequency vs RFA
LM3478 10135505.png
Figure 6. Drive Voltage vs Input Voltage
LM3478 10135562.png
Figure 8. COMP Pin Voltage vs Load Current
LM3478 10135558.png
Figure 10. Efficiency vs Load Current (5-V Input and 12-V Output)
LM3478 10135553.png
Figure 12. Efficiency vs Load Current (3.3-V Input and 5-V Output)
LM3478 10135556.png
Figure 14. Error Amplifier Phase
LM3478 10135557.png
Figure 16. Short Circuit Sense Voltage vs Input Voltage
LM3478 10135546.png
Figure 18. Shutdown Threshold Hysteresis vs Temperature