TIDUEB8C July   2018  – March 2021 TPS274160

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
    1. 1.1 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Highlighted Products
      1. 2.2.1 LM5165
      2. 2.2.2 TLC59282
      3. 2.2.3 TPS4H160-Q1
      4. 2.2.4 INA253
      5. 2.2.5 TIOL111
    3. 2.3 System Design Theory
      1. 2.3.1 IO-Link PHY
      2. 2.3.2 Current Sink
      3. 2.3.3 Power Supply for L+
      4. 2.3.4 Power Supply
      5. 2.3.5 Pinouts
    4. 2.4 Software Frame Handler
      1. 2.4.1 PRU-ICSS IO-Link Frame-Handler
        1. 2.4.1.1 Performance Advantages and Benefits
        2. 2.4.1.2 Principle of Operation
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Required Hardware and Software
      1. 3.1.1 Hardware
      2. 3.1.2 Software
    2. 3.2 Testing and Results
      1. 3.2.1 Test Setup
      2. 3.2.2 Test Results
        1. 3.2.2.1 IO-Link Wake-Up Pulse
        2. 3.2.2.2 L+ Turnon Behavior
        3. 3.2.2.3 Current Sink on CQ
        4. 3.2.2.4 Residue Voltage
        5. 3.2.2.5 IO-Link Physical Layer Test Summary
        6. 3.2.2.6 Current Sense on Each Port
        7. 3.2.2.7 TPS4H160 Thermal Behavior
  9. 4Design Files
    1. 4.1 Schematics
    2. 4.2 Bill of Materials
    3. 4.3 PCB Layout Recommendations
      1. 4.3.1 Layout Prints
    4. 4.4 Altium Project
    5. 4.5 Gerber Files
    6. 4.6 Assembly Drawings
  10. 5Software Files
  11. 6Related Documentation
    1. 6.1 Trademarks
  12. 7About the Author
  13. 8Revision History

2.2.1 LM5165

The LM5165 converter is an easy-to-use synchronous buck DC-DC regulator that operates from a 3-V to 65-V supply voltage. The device is intended for step-down conversions from 3.3-V, 5-V, 12-V, 24-V, and 48-V unregulated, semi-regulated and fully-regulated supply rails. With integrated high-side and low-side power MOSFETs, the LM5165 delivers up to 150-mA DC load current with high efficiency and ultra-low input quiescent current in a very small solution size. Designed for simple implementation, a choice of operating modes offers flexibility to optimize its usage according to the target application. In constant on-time (COT) mode of operation, ideal for low-noise, high current, fast load transient requirements, the device operates with predictive on-time switching pulse. A quasi-fixed switching frequency over the input voltage range is achieved by using an input voltage feedforward to set the on-time. Alternatively, pulse frequency modulation (PFM) mode, complemented by an adjustable peak current limit, achieves exceptional light-load efficiency performance. Control-loop compensation is not required with either operating mode, reducing design time and external component count.

GUID-280A1862-ADB5-401C-BCD8-4E78F3E3A5E3-low.gifFigure 2-2 LM5165 Block Diagram

Key features relevant for this design are:

  • Wide input voltage range of 3 V to 65 V
  • Fixed 3.3-V output voltages
  • 150-mA synchronous buck converter
  • Integrated 2-Ω PMOS buck switch
  • Integrated 1-Ω NMOS synchronous rectifier
    • Eliminates external rectifier diode
  • Selectable PFM or COT mode operation
  • No loop compensation or bootstrap components
This device allows to easily implement a small power supply solution with a wide input-voltage range.