ZHCSLU2B December   2021  – October 2023 LM63460-Q1

PRODUCTION DATA  

  1.   1
  2. 1 特性
  3. 2 应用
  4. 3 说明
  5. 4 Revision History
  6. 5 Device Comparison Table
  7. 6 Pin Configuration and Functions
    1. 6.1 Wettable Flanks
    2. 6.2 Pinout Design for Clearance and FMEA
  8. 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 Timing Characteristics
    7. 7.7 Systems Characteristics
    8. 7.8 Typical Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Input Voltage Range (VIN1, VIN2)
      2. 8.3.2  Output Voltage Setpoint (FB)
      3. 8.3.3  Precision Enable and Input Voltage UVLO (EN/SYNC)
      4. 8.3.4  Frequency Synchronization (EN/SYNC)
      5. 8.3.5  Clock Locking
      6. 8.3.6  Adjustable Switching Frequency (RT)
      7. 8.3.7  Power-Good Monitor (PGOOD)
      8. 8.3.8  Bias Supply Regulator (VCC, BIAS)
      9. 8.3.9  Bootstrap Voltage and UVLO (CBOOT)
      10. 8.3.10 Spread Spectrum
      11. 8.3.11 Soft Start and Recovery From Dropout
      12. 8.3.12 Overcurrent and Short-Circuit Protection
      13. 8.3.13 Thermal Shutdown
      14. 8.3.14 Input Supply Current
    4. 8.4 Device Functional Modes
      1. 8.4.1 Shutdown Mode
      2. 8.4.2 Standby Mode
      3. 8.4.3 Active Mode
        1. 8.4.3.1 CCM Mode
        2. 8.4.3.2 AUTO Mode – Light-Load Operation
          1. 8.4.3.2.1 Diode Emulation
          2. 8.4.3.2.2 Frequency Foldback
        3. 8.4.3.3 FPWM Mode – Light-Load Operation
        4. 8.4.3.4 Minimum On-Time (High Input Voltage) Operation
        5. 8.4.3.5 Dropout
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Design 1 – Automotive Synchronous Buck Regulator at 2.1 MHz
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1  Custom Design With WEBENCH® Tools
          2. 9.2.1.2.2  Setting the Output Voltage
          3. 9.2.1.2.3  Choosing the Switching Frequency
          4. 9.2.1.2.4  Inductor Selection
          5. 9.2.1.2.5  Output Capacitor Selection
          6. 9.2.1.2.6  Input Capacitor Selection
          7. 9.2.1.2.7  Bootstrap Capacitor
          8. 9.2.1.2.8  VCC Capacitor
          9. 9.2.1.2.9  BIAS Power Connection
          10. 9.2.1.2.10 Feedforward Network
          11. 9.2.1.2.11 Input Voltage UVLO
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Design 2 – Automotive Synchronous Buck Regulator at 400 kHz
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
        1. 9.4.1.1 Thermal Design and Layout
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 第三方产品免责声明
      2. 10.1.2 Development Support
        1. 10.1.2.1 Custom Design With WEBENCH® Tools
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 接收文档更新通知
    4. 10.4 支持资源
    5. 10.5 Trademarks
    6. 10.6 静电放电警告
    7. 10.7 术语表
  12. 11Mechanical, Packaging, and Orderable Information

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8.1 Overview

The LM63460-Q1 is an easy-to-use, synchronous buck DC/DC converter designed for a wide variety of automotive applications where strict reliability and low EMI are of paramount importance. The devices operates over an input voltage range of 3.95 V to 36 V, with operation down to 3 V after start-up and transients as high as 42 V. The LM63460-Q1 delivers up to 6-A DC load current with high conversion efficiency and ultra-low input quiescent current in a very small design size.

The LM63460-Q1 has a programmable switching frequency between 200 kHz to 2.2 MHz using its RT pin, including sub-AM band at 400 kHz and above the AM band at 2.1 MHz. The converter includes specific features for optimal EMI performance in noise-sensitive automotive applications, such as:

  • An optimized package and pinout design enables a shielded switch-node layout that mitigates radiated EMI.
  • Parallel input paths with a symmetrical capacitor layout minimize parasitic inductance, switch-voltage ringing, and radiated field coupling.
  • Pseudo-random spread spectrum (PRSS) modulation reduces peak emissions.
  • Frequency synchronization and optional FPWM mode enable constant switching frequency across the full load current range.
  • Integrated high-side and low-side power MOSFETs with enhanced gate-drive control enable low-noise PWM switching.

Together, these features significantly reduce EMI filtering requirements, thus eliminating shielding and other expensive EMI mitigation measures, while helping to meet the CISPR 25 Class 5 automotive EMI standard for conducted and radiated emissions.

The enhanced HotRod QFN package of the LM63460-Q1 has a carefully designed wettable-flank pinout arrangement that provides additional clearance spacing between adjacent VIN, SW, or PGND power pins to improve reliability and pin FMEA. The converter also incorporates other features for comprehensive system requirements, including:

  • A precision enable input with hysteresis for programmable line undervoltage lockout (UVLO)
  • Cycle-by-cycle peak and valley current limits for optimal inductor sizing
  • An open-drain power-good monitor for power-rail sequencing and fault reporting
  • Internally fixed output voltage soft start
  • Monotonic start-up into prebiased loads
  • Thermal shutdown with automatic recovery

The LM63460-Q1 is qualified to AEC-Q100 grade 1 and has electrical characteristics specified up to a maximum junction temperature of 150°C. The following help provide an ideal point-of-load regulator solution for automotive applications requiring enhanced reliability and durability:

  • Wide input voltage range
  • Low quiescent current consumption
  • Optimized thermal design and high-temperature operation
  • Improved pin FMEA
  • Small design size