SNVSBL7A March   2020  – August 2020 LM25184

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  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
    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  Integrated Power MOSFET
      2. 7.3.2  PSR Flyback Modes of Operation
      3. 7.3.3  Setting the Output Voltage
        1. 7.3.3.1 Diode Thermal Compensation
      4. 7.3.4  Control Loop Error Amplifier
      5. 7.3.5  Precision Enable
      6. 7.3.6  Configurable Soft Start
      7. 7.3.7  External Bias Supply
      8. 7.3.8  Minimum On-Time and Off-Time
      9. 7.3.9  Overcurrent Protection
      10. 7.3.10 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Standby Mode
      3. 7.4.3 Active Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Design 1: Wide VIN, Low IQ PSR Flyback Converter Rated at 12 V, 1 A
        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  Custom Design With Excel Quickstart Tool
          3. 8.2.1.2.3  Flyback Transformer – T1
          4. 8.2.1.2.4  Flyback Diode – DFLY
          5. 8.2.1.2.5  Leakgae Inductance Clamp Circuit – DF, DCLAMP
          6. 8.2.1.2.6  Output Capacitor – COUT
          7. 8.2.1.2.7  Input Capacitor – CIN
          8. 8.2.1.2.8  Feedback Resistor – RFB
          9. 8.2.1.2.9  Thermal Compensation Resistor – RTC
          10. 8.2.1.2.10 UVLO Resistors – RUV1, RUV2
          11. 8.2.1.2.11 Soft-Start Capacitor – CSS
      2. 8.2.2 Application Curves
      3. 8.2.3 Design 2: PSR Flyback Converter With Dual Outputs of 15 V and –8 V at 0.5 A
        1. 8.2.3.1 Design Requirements
        2. 8.2.3.2 Detailed Design Procedure
          1. 8.2.3.2.1 Flyback Transformer – T1
          2. 8.2.3.2.2 Flyback Diodes – DFLY1 and DFLY2
          3. 8.2.3.2.3 Input Capacitor – CIN
          4. 8.2.3.2.4 Output Capacitors – COUT1, COUT2
          5. 8.2.3.2.5 Feedback Resistor – RFB
          6. 8.2.3.2.6 Thermal Compensation Resistor – RTC
          7. 8.2.3.2.7 Output Voltage Clamp Zeners – DOUT1 and DOUT2
        3. 8.2.3.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Examples
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
      2. 11.1.2 Development Support
        1. 11.1.2.1 Custom Design With WEBENCH® Tools
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Support Resources
    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

8.2.2 Application Curves

Unless otherwise stated, application performance curves were taken at TA = 25°C.

GUID-C9C162B2-5BDD-40C5-B623-18858C456DF5-low.gifFigure 8-2 Efficiency (Linear Scale)
GUID-3B917113-E51D-4E84-8C71-FD67B6CD913F-low.gifFigure 8-4 Load Regulation (Linear Scale)
GUID-AA2F1446-66E7-4470-80B8-7E4D1EFB9A09-low.gif
VIN stepped to 24 V 12-Ω Load
Figure 8-6 Start-up Characteristic
GUID-8C63C197-DC58-4615-AA8F-900CEB26ED13-low.gif
VIN = 13.5 V IOUT = 1 A
Figure 8-8 Switch Node Voltage
GUID-D08CF958-2FB7-4CA2-9B3A-6AE336A753E8-low.gif
VIN = 36 V IOUT = 1 A
Figure 8-10 Switch Node Voltage
GUID-D0E61D78-4D93-41F9-BE60-29CF6715B6C0-low.gif
VIN = 13.5 V
Figure 8-12 Load Transient, 0.1 A to 1 A, 0.1 A/µs
GUID-217D5A5A-EA3A-445D-8BA9-110B581CCDB7-low.gif
VIN = 24 V 150 kHz to 30 MHz LIN = 4.7 µH
IOUT = 1 A CIN = 10 µF
Figure 8-14 CISPR 25 Class 5 Conducted EMI Plot
GUID-751F8489-FA0C-401E-90B5-8C1E4F2B8627-low.gifFigure 8-3 Efficiency (Log Scale)
GUID-6E38FAF2-9A16-4DC4-BA7D-BC482C08DE1A-low.gifFigure 8-5 Load Regulation (Log Scale)
GUID-C3743522-F2BF-48F3-A4C8-B4EA0B8958CE-low.gif
VIN = 24 V 12-Ω Load
Figure 8-7 Enable ON and OFF Characteristic
GUID-A91E7BC4-77DF-4982-A640-4DBBA4BA97F0-low.gif
VIN = 24 V IOUT = 1 A
Figure 8-9 Switch Node Voltage
GUID-CA42A214-83A2-4CC2-9A67-F25EE15D2D3C-low.gif
VIN = 24 V
Figure 8-11 Load Transient, 0.1 A to 1 A, 0.1 A/µs
GUID-123DB8E2-20DE-49EB-8E6A-CF814EA95FA4-low.gif
VIN = 6 V
Figure 8-13 Load Transient, 0.1 A to 0.5 A, 0.1 A/µs
GUID-2A0D172F-6768-4F99-9AAE-9C1E0C79CAEF-low.gif
VIN = 24 V 30 MHz to 108 MHz LIN = 4.7 µH
IOUT = 1 A CIN = 10 µF
Figure 8-15 CISPR 25 Class 5 Conducted EMI Plot