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

8.16 Output On/Off Inhibit (INH)

The INH pin provides electrical on/off control of the device. Once the INH pin voltage exceeds the threshold voltage, the device starts operation. If the INH pin voltage is pulled below the threshold voltage, the regulator stops switching and enters low quiescent current state.

The INH pin has an internal pull-up current source, allowing the user to float the INH pin for enabling the device. If an application requires controlling the INH pin, use an open drain/collector device, or a suitable logic gate to interface with the pin.

Figure 20 shows the typical application of the inhibit function. The Inhibit control has its own internal pull-up to VIN potential. An open-collector or open-drain device is recommended to control this input.

Turning Q1 on applies a low voltage to the inhibit control (INH) pin and disables the output of the supply, shown in Figure 21. If Q1 is turned off, the supply executes a soft-start power-up sequence, as shown in Figure 22. A regulated output voltage is produced within 2 ms. The waveforms were measured with a 5-A constant current load.

LMZ31520 LMZ31530_INHcontrol.gifFigure 20. Typical Inhibit Control
LMZ31520 INHshutdown.pngFigure 21. Inhibit Turn-Off
LMZ31520 INHstartup.pngFigure 22. Inhibit Turn-On