SLVSBM9E October   2013  – September 2018 LMZ31520

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
    1.     Efficiency
  3. 3 Description
    1.     Simplified Application
  4. 4 Specifications
    1. 4.1 Absolute Maximum Ratings
    2. 4.2 Recommended Operating Conditions
    3. 4.3 Thermal Information
    4. 4.4 Package Specifications
    5. 4.5 Electrical Characteristics
  5. 5 Device Information
    1.     Pin Functions
    2. 5.1 Functional Block Diagram
  6. 6 Typical Characteristics (PVIN = VIN = 12 V)
  7. 7 Typical Characteristics (PVIN = VIN = 5 V)
  8. 8 Application Information
    1. 8.1  Adjusting the Output Voltage
    2. 8.2  Frequency Select
    3. 8.3  Capacitor Recommendations for the LMZ31520 Power Supply
      1. 8.3.1 Capacitor Technologies
        1. 8.3.1.1 Electrolytic, Polymer-Electrolytic Capacitors
        2. 8.3.1.2 Ceramic Capacitors
        3. 8.3.1.3 Tantalum, Polymer-Tantalum Capacitors
        4. 8.3.1.4 Input Capacitor
        5. 8.3.1.5 Output Capacitor
    4. 8.4  Transient Response
    5. 8.5  Application Curves Device configured for FCCM mode of operation, (pin 3 connected to pin 19).
    6. 8.6  Application Schematics
    7. 8.7  Custom Design With WEBENCH® Tools
    8. 8.8  VIN and PVIN Input Voltage
    9. 8.9  3.3 V PVIN Operation
    10. 8.10 Power Good (PWRGD)
    11. 8.11 Slow Start (SS_SEL)
    12. 8.12 Auto-Skip Eco-mode / Forced Continuous Conduction Mode
    13. 8.13 Power-Up Characteristics
    14. 8.14 Pre-Biased Start-Up
    15. 8.15 Remote Sense
    16. 8.16 Output On/Off Inhibit (INH)
    17. 8.17 Overcurrent Protection
    18. 8.18 Current Limit (ILIM) Adjust
    19. 8.19 Thermal Shutdown
    20. 8.20 Layout Considerations
    21. 8.21 EMI
  9. 9 Revision History
  10. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Development Support
        1. 10.1.1.1 Custom Design With WEBENCH® Tools
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Community Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  11. 11Mechanical, Packaging, and Orderable Information
    1. 11.1 Tape and Reel Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RLG|72
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.13 Power-Up Characteristics

When configured as shown in the front page schematic, the LMZ31520 produces a regulated output voltage following the application of a valid input voltage. During the power-up, internal soft-start circuitry slows the rate that the output voltage rises, thereby limiting the amount of in-rush current that can be drawn from the input source. Figure 18 shows the start-up waveforms for a LMZ31520, operating from a 5-V input (PVIN=VIN) and with the output voltage adjusted to 1.8 V. Figure 19 shows the start-up waveforms for a LMZ31520 starting up into a pre-biased output voltage. The waveforms were measured with a 15-A constant current load.

LMZ31520 startup.pngFigure 18. Start-Up Waveforms
LMZ31520 prebiasstartup.pngFigure 19. Start-up into Pre-bias