SNVSB27C June   2018  – October 2020 LMR33620-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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 Timing Characteristics
    7. 6.7 System Characteristics
    8. 6.8 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 Power-Good Flag Output
      2. 7.3.2 Enable and Start-up
      3. 7.3.3 Current Limit and Short Circuit
      4. 7.3.4 Undervoltage Lockout and Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Auto Mode
      2. 7.4.2 Dropout
      3. 7.4.3 Minimum Switch On-Time
  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  Custom Design With WEBENCH® Tools
        2. 8.2.2.2  Choosing the Switching Frequency
        3. 8.2.2.3  Setting the Output Voltage
          1. 8.2.2.3.1 Fixed Output Voltage Option
        4. 8.2.2.4  Inductor Selection
        5. 8.2.2.5  Output Capacitor Selection
        6. 8.2.2.6  Input Capacitor Selection
        7. 8.2.2.7  CBOOT
        8. 8.2.2.8  VCC
        9. 8.2.2.9  CFF Selection
        10. 8.2.2.10 External UVLO
        11. 8.2.2.11 Maximum Ambient Temperature
      3. 8.2.3 Application Curves
    3. 8.3 What to Do and What Not to Do
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Ground and Thermal Considerations
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
        1. 11.1.1.1 Custom Design With WEBENCH® Tools
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Support Resources
    4. 11.4 Receiving Notification of Documentation Updates
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RNX|12
Thermal pad, mechanical data (Package|Pins)
Orderable Information
8.2.2.3.1 Fixed Output Voltage Option

With the fixed output voltage version, the feed-back divider is internal to the device. Therefore, an external divider is not needed and the FB input is connected directly to VOUT. The total resistance of the internal divider is about 2 MΩ (see Section 6.5). The large value of the divider reduces the loading on the output and helps to reduce the no-load input current of the system. For those applications that require the lowest no-load input current, without resorting to large value feed-back resistors, the fixed output voltage option is a good solution. Figure 8-2 and Figure 8-3 show the no-load and light load input supply current for the fixed option, using the BOM from Table 8-3 and with RFBT = 0 Ω and RFBB = open. Figure 8-4 and Figure 8-5 show the same characteristics for the 3.3-V fixed option.

GUID-1725E402-7C24-466F-9FF6-4D0AA81432BA-low.pngFigure 8-2 No-load Input Supply Current for 5-V Fixed Output Option
GUID-699D180E-F178-44CC-A28A-025D971598A7-low.pngFigure 8-4 No-load Input Supply Current for 3.3-V Fixed Output Option
GUID-B65237CA-49F7-44DA-ACB4-59675B6575FF-low.pngFigure 8-3 Input Supply Current vs Output Current for 5-V Fixed Output Option
GUID-DE49A0EA-6E63-4022-9614-661C8E3768E1-low.pngFigure 8-5 Input Supply Current vs Output Current for 3.3-V Fixed Output Option