TIDT445 May   2025

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 Load Transient Test Circuit
    3. 2.3 Highlighted Products
      1. 2.3.1 LM5137F-Q1 Overview
  9. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
    2. 3.2 Test Setup
    3. 3.3 Test Results
      1. 3.3.1 Efficiency Data
      2. 3.3.2 Efficiency Graphs
      3. 3.3.3 Output Voltage Ripple
      4. 3.3.4 Thermal Images
      5. 3.3.5 Bode Plots
      6. 3.3.6 Load Transients
  10. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
      3. 4.1.3 Altium Project
      4. 4.1.4 Gerber Files
      5. 4.1.5 Assembly Drawings
    2. 4.2 Documentation Support
    3. 4.3 Support Resources
    4. 4.4 Trademarks
  11. 5About the Author

LM5137F-Q1 Overview

The LM5137F-Q1 is an 80V dual-channel buck controller offered from a family with three options for functional safety: Capable, ASIL B, or ASIL D. The device uses an interleaved, stackable, peak current mode architecture for easy loop compensation, fast transient response, excellent load and line regulation, and accurate current sharing with paralleled phases for high output current. A high-side switch minimum on-time of 15ns facilitates large step-down ratios, enabling the direct conversion from 12V, 24V, or 48V automotive inputs to low-voltage rails for reduced system design cost and complexity. The LM5137F-Q1 continues operating during input voltage dips as low as 4V, at 100% duty cycle if needed.

Features:

  • AEC-Q100 qualified for automotive applications
  • Device temperature grade 1: –40°C to 125°C ambient operating temperature
  • Functional Safety-Compliant targeted
  • Developed for functional safety applications
  • Three orderable part numbers for Capable, ASIL B, and ASIL D options
  • Documentation available to aid ISO 26262 system design up to ASIL D are available upon production release
  • Systematic capability up to ASIL D targeted
  • Hardware integrity up to ASIL D targeted
  • Versatile dual synchronous buck DC/DC controller
  • 1% accurate, fixed 3.3V, 5V, 12V, or adjustable outputs from 0.8V to 60V
  • Current monitor output for each channel
  • Charge-pump gate drivers for 100% duty cycle
  • No-load sleep current of 12.7µA (typical)
  • Internal hiccup-mode overcurrent protection
  • Two interleaved synchronous buck channels
  • Dual channel or single-output multiphase
  • Stackable up to four phases
  • Designed for ultra-low EMI requirements
  • Dual Random Spread Spectrum (DRSS)
  • Switching frequency from 100kHz to 2.5MHz
  • VQFN-36 package with wettable flanks