SNVSB11B June   2018  – May 2019 LMZM33606

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
    1.     Simplified Schematic
  3. 3 Description
    1.     Minimum Solution Size
    2.     Typical Efficiency (Auto Mode)
  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 Switching Characteristics
    7. 6.7 Typical Characteristics (VIN = 12 V)
    8. 6.8 Typical Characteristics (VIN = 24 V)
    9. 6.9 Typical Characteristics (VIN = 36 V)
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Adjusting the Output Voltage
      2. 7.3.2  Input Capacitor Selection
      3. 7.3.3  Output Capacitor Selection
      4. 7.3.4  Transient Response
      5. 7.3.5  Feed-Forward Capacitor
      6. 7.3.6  Switching Frequency (RT)
      7. 7.3.7  Synchronization (SYNC/MODE)
      8. 7.3.8  Output Enable (EN)
      9. 7.3.9  Programmable System UVLO (EN)
      10. 7.3.10 Internal LDO and BIAS_SEL
      11. 7.3.11 Power Good (PGOOD) and Power Good Pull-Up (PGOOD_PU)
      12. 7.3.12 Mode Select (Auto or FPWM)
      13. 7.3.13 Soft Start and Voltage Tracking
      14. 7.3.14 Voltage Dropout
      15. 7.3.15 Overcurrent Protection (OCP)
      16. 7.3.16 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Active Mode
      2. 7.4.2 Auto Mode
      3. 7.4.3 FPWM Mode
      4. 7.4.4 Shutdown Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Output Voltage Setpoint
        2. 8.2.2.2 Setting the Switching Frequency
        3. 8.2.2.3 Input Capacitors
        4. 8.2.2.4 Output Capacitor Selection
        5. 8.2.2.5 Feed-Forward Capacitor (CFF)
        6. 8.2.2.6 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Theta JA vs PCB Area
    4. 10.4 Package Specifications
    5. 10.5 EMI
      1. 10.5.1 EMI Plots
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information
    1. 12.1 Tape and Reel Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RLX|41
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.3.14 Voltage Dropout

Voltage dropout is the minimum difference between the input voltage and output voltage that is required to maintain output voltage regulation while providing the rated output current.

To ensure the LMZM33606 maintains output voltage regulation at the recommended switching frequency, over the operating temperature range, the following requirements apply:

For output voltages ≤ 5 V, the minimum VIN is 3.5 V or (VOUT + 1 V), whichever is greater.

For output voltages > 5 V, the minimum VIN is (1.1 × VOUT).

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However, if fixed switching frequency operation is not required, the LMZM33606 operates in a frequency foldback mode when the dropout voltage is less than the recommendations above. Frequency foldback reduces the switching frequency to allow the output voltage to maintain regulation as input voltage decreases. Figure 41 through Figure 44 show typical dropout voltage and frequency foldback curves for 5 V and 12 V outputs at TA = 25°C. (As ambient temperature increases, dropout voltage and frequency foldback occur at higher input voltages.)

LMZM33606 D024_5VDropOut.gif
VOUT = 5 V fSW = 500 kHz
Figure 41. Voltage Dropout
LMZM33606 D026_12VDropOut.gif
VOUT = 12 V fSW = 800 kHz
Figure 43. Voltage Dropout
LMZM33606 D023_5VFreqFoldback.gif
VOUT = 5 V fSW = 500 kHz
Figure 42. Frequency Foldback
LMZM33606 D025_12VFreqFoldback.gif
VOUT = 12 V fSW = 800 kHz
Figure 44. Frequency Foldback