SNVSBE0G October   2020  – May 2024 LMR43610-Q1 , LMR43620-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 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 System Characteristics
    7. 6.7 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Enable, Start-Up, and Shutdown
      2. 7.3.2  External CLK SYNC (with MODE/SYNC)
        1. 7.3.2.1 Pulse-Dependent MODE/SYNC Pin Control
      3. 7.3.3  Adjustable Switching Frequency (with RT)
      4. 7.3.4  Power-Good Output Operation
      5. 7.3.5  Internal LDO, VCC, and VOUT/FB Input
      6. 7.3.6  Bootstrap Voltage and VBOOT-UVLO (BOOT Terminal)
      7. 7.3.7  Output Voltage Selection
      8. 7.3.8  Spread Spectrum
      9. 7.3.9  Soft Start and Recovery from Dropout
        1. 7.3.9.1 Recovery from Dropout
      10. 7.3.10 Current Limit and Short Circuit
      11. 7.3.11 Thermal Shutdown
      12. 7.3.12 Input Supply Current
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Standby Mode
      3. 7.4.3 Active Mode
        1. 7.4.3.1 CCM Mode
        2. 7.4.3.2 Auto Mode – Light-Load Operation
          1. 7.4.3.2.1 Diode Emulation
          2. 7.4.3.2.2 Frequency Reduction
        3. 7.4.3.3 FPWM Mode – Light-Load Operation
        4. 7.4.3.4 Minimum On-Time (High Input Voltage) Operation
        5. 7.4.3.5 Dropout
  9. 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  Choosing the Switching Frequency
        2. 8.2.2.2  Setting the Output Voltage
          1. 8.2.2.2.1 FB for Adjustable Output
        3. 8.2.2.3  Inductor Selection
        4. 8.2.2.4  Output Capacitor Selection
        5. 8.2.2.5  Input Capacitor Selection
        6. 8.2.2.6  CBOOT
        7. 8.2.2.7  VCC
        8. 8.2.2.8  CFF Selection
        9. 8.2.2.9  External UVLO
        10. 8.2.2.10 Maximum Ambient Temperature
      3. 8.2.3 Application Curves
    3. 8.3 Best Design Practices
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
        1. 8.5.1.1 Ground and Thermal Considerations
      2. 8.5.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Third-Party Products Disclaimer
      2. 9.1.2 Device Nomenclature
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

3 Description

The LMR436x0-Q1 is the industry smallest 36V, 2A, and 1A synchronous step-down DC/DC converters in a 2mm × 2mm HotRod package. This easy-to-use converter supports a wide input voltage range of 3.0V to 36V with transients up to 42V.

The LMR43620-Q1 is specifically designed to meet low standby power requirements for always on, automotive applications. Auto mode enables frequency foldback when operating at light loads, allowing an unloaded current consumption of 1.5µA at 13.5VIN and high light load efficiency. A seamless transition between PWM and PFM modes along with very low MOSFET ON resistances provide exceptional efficiency across the entire load range.

The control architecture and feature set are designed for an ultra-small design size. The device uses peak current mode control to minimize output capacitance. The LMR436x0-Q1 minimizes input filter size by using dual random spread spectrum, a low-EMI HotRod package, and an optimized pinout. The MODE/SYNC and RT pin variants can be used to set or synchronize the frequency between 200kHz and 2.2MHz to avoid noise sensitive frequency bands.

The rich feature set of the LMR436x0-Q1 is designed to simplify implementation for a wide range of automotive end equipments.

Device Information
PART NUMBER(3) RATED CURRENT PACKAGE (1) PACKAGE SIZE(2)
LMR43620-Q1 2A RPE (VQFN-HR, 9) 2.00mm × 2.00mm
LMR43610-Q1 1A
(1) For more information, see Section 11.
(2) The package size (length × width) is a nominal value and includes pins, where applicable.
LMR43610-Q1 LMR43620-Q1 Typical Design Size (10mm × 10mm)Typical Design Size (10mm × 10mm)
LMR43610-Q1 LMR43620-Q1 Efficiency: VOUT = 3.3V (Fixed), 2.2MHzEfficiency: VOUT = 3.3V (Fixed), 2.2MHz