SNVSAA7B December   2015  – July 2021 LM53625-Q1 , LM53635-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 System Characteristics
    7. 7.7 Timing Characteristics
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
      1. 8.2.1 Control Scheme
    3. 8.3 Feature Description
      1. 8.3.1 RESET Flag Output
      2. 8.3.2 Enable and Start-Up
      3. 8.3.3 Soft-Start Function
      4. 8.3.4 Current Limit
      5. 8.3.5 Hiccup Mode
      6. 8.3.6 Synchronizing Input
      7. 8.3.7 Undervoltage Lockout (UVLO) and Thermal Shutdown (TSD)
      8. 8.3.8 Input Supply Current
    4. 8.4 Device Functional Modes
      1. 8.4.1 AUTO Mode
      2. 8.4.2 FPWM Mode
      3. 8.4.3 Dropout
      4. 8.4.4 Input Voltage Frequency Foldback
    5. 8.5 Spread-Spectrum Operation
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 General Application
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 External Components Selection
            1. 9.2.1.2.1.1 Input Capacitors
              1. 9.2.1.2.1.1.1 Input Capacitor Selection
            2. 9.2.1.2.1.2 Output Inductors and Capacitors Selection
              1. 9.2.1.2.1.2.1 Inductor Selection
              2. 9.2.1.2.1.2.2 Output Capacitor Selection
          2. 9.2.1.2.2 Setting the Output Voltage
            1. 9.2.1.2.2.1 FB for Adjustable Versions
          3. 9.2.1.2.3 VCC
          4. 9.2.1.2.4 BIAS
          5. 9.2.1.2.5 CBOOT
          6. 9.2.1.2.6 Maximum Ambient Temperature
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Fixed 5-V Output for USB-Type Applications
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Curves
      3. 9.2.3 Fixed 3.3-V Output
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
        3. 9.2.3.3 Application Curves
      4. 9.2.4 Adjustable Output
        1. 9.2.4.1 Design Requirements
        2. 9.2.4.2 Detailed Design Procedure
        3. 9.2.4.3 Application Curves
    3. 9.3 What to Do and What Not to Do
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Support Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

8.1 Overview

The LM53625/35-Q1 is a wide input voltage range, low quiescent current, high performance regulator with internal compensation designed specifically for the automotive market. This device is designed to minimize end-product cost and size while operating in demanding automotive environments. Normal operating frequency is 2.1 MHz allowing the use of small passive components. Because the operating frequency is above the AM band, significant saving in input filtering is also achieved. This device has a low unloaded current consumption eliminating the need for an external back-up LDO. The LM53625/35-Q1 low shutdown current and high maximum operating voltage also allows the elimination of an external load switch. To further reduce system cost, an advanced reset output is provided, which can often eliminate the use of an external reset device.

The LM53625/35-Q1 is designed with a flip-chip or HotRod technology, greatly reducing the parasitic inductance of pins. In addition, the layout of the device allows for reduction in the radiated noise generated by the switching action through partial cancellation of the current generated magnetic field.

As a result the switch-node waveform exhibits less overshoot and ringing.

GUID-63881EA2-EE92-44B2-9E6C-C63FB74AD9EC-low.pngFigure 8-1 Switch Node Waveform (VIN=13.5V, IOUT=3.5A)

The LM53625/35-Q1 is AEC-Q1 qualified as well as having electrical characteristics ensured up to a maximum junction temperature of 150°C.

The LM53625/35-Q1 is available in VQFN package with wettable-flanks which allows easy inspection of the soldering job without the requirement of X-ray checks.

Please note that, throughout this data sheet, references to the LM53625 apply equally to the LM53635. The difference between the two devices is the maximum output current and specified MOSFET current limits.