TIDUEP0 May   2020

 

  1.    Description
  2.    Resources
  3.    Features
  4.    Applications
  5. 1Design Images
  6. 2System Description
    1. 2.1 Key System Specifications
  7. 3System Overview
    1. 3.1 Block Diagram
    2. 3.2 Design Considerations
      1. 3.2.1 Small Compact Size
      2. 3.2.2 Transformer less Solution
    3. 3.3 Highlighted Products
      1. 3.3.1  TPD4E05U06 4-Channel Ultra-Low-Capacitance IEC ESD Protection Diode
      2. 3.3.2  TPD2EUSB30 2-Channel ESD Solution for SuperSpeed USB 3.0 Interface
      3. 3.3.3  2.3.3 HD3SS3220 10Gbps USB 3.1 USB Type-C 2:1 MUX With DRP Controller
      4. 3.3.4  TPS54218 2.95V to 6V Input, 2A Synchronous Step-Down SWIFT™ Converter
      5. 3.3.5  TPS54318 2.95V to 6V Input, 3A Synchronous Step-Down SWIFT™ Converter
      6. 3.3.6  CSD19538Q3A 100V, N ch NexFET MOSFET™, single SON3x3, 49mOhm
      7. 3.3.7  LM3488 2.97V to 40V Wide Vin Low-Side N-Channel Controller for Switching Regulators
      8. 3.3.8  TPS61178 20-V Fully Integrated Sync Boost with Load Disconnect
      9. 3.3.9  LMZM23601 36-V, 1-A Step-Down DC-DC Power Module in 3.8-mm × 3-mm Package
      10. 3.3.10 TPS7A39 Dual, 150mA, Wide-Vin, Positive and Negative Low-Dropout (LDO) Voltage Regulator
      11. 3.3.11 TPS74201 Single-output 1.5-A LDO regulator, adjustable (0.8V to 3.3V), any or no cap, programmable soft start
      12. 3.3.12 LP5910 300-mA low-noise low-IQ low-dropout (LDO) linear regulator
      13. 3.3.13 LP5907 250-mA ultra-low-noise low-IQ low-dropout (LDO) linear
      14. 3.3.14 INA231 28V, 16-bit, i2c output current/voltage/power monitor w/alert in wcsp
    4. 3.4 System Design Theory
      1. 3.4.1 Input Section
      2. 3.4.2 Designing of SEPIC based High Voltage Supply
        1. 3.4.2.1  Basic Operation Principle of SEPIC Converter
        2. 3.4.2.2  Design of Dual SEPIC Supply using uncoupled inductors
        3. 3.4.2.3  Duty Cycle
        4. 3.4.2.4  Inductor Selection
        5. 3.4.2.5  Power MOSFET Selection
        6. 3.4.2.6  Output Diode Selection
        7. 3.4.2.7  Coupling Capacitor Selection
        8. 3.4.2.8  Output Capacitor Selection
        9. 3.4.2.9  Input Capacitor Selection
        10. 3.4.2.10 Programming the Output Voltage
      3. 3.4.3 Designing the Low Voltage Power Supply
      4. 3.4.4 Designing the TPS54218 through Webench Power Designer
      5. 3.4.5 ± 5V Transmit Supply Generation
      6. 3.4.6 System Clock Synchronization
      7. 3.4.7 Power and data output connector
      8. 3.4.8 System Current and Power Monitoring
  8. 4Hardware, Software, Testing Requirements, and Test Results
    1. 4.1 Testing and Results
      1. 4.1.1 Test Setup
      2. 4.1.2 Test Results
        1. 4.1.2.1 High Voltage Power Supply
        2. 4.1.2.2 Output Ripple Measurement
        3. 4.1.2.3 Load Transient Test
        4. 4.1.2.4 Noise Measurement
        5. 4.1.2.5 Thermal Performance
        6. 4.1.2.6 Low Voltage Power Supply
          1. 4.1.2.6.1 Thermal Performance
          2. 4.1.2.6.2 FX3 Supply
  9. 5Layout Guidelines
    1. 5.1 High-Voltage Supply Layout
    2. 5.2 USB Section Layout Guidelines
  10. 6Design Files
    1. 6.1 Schematics
    2. 6.2 Bill of Materials
    3. 6.3 PCB Layout Recommendations
      1. 6.3.1 Layout Prints
    4. 6.4 Altium Project
    5. 6.5 Gerber Files
    6. 6.6 Assembly Drawings
  11. 7Software Files
  12. 8Related Documentation
    1. 8.1 Trademarks
    2. 8.2 Third-Party Products Disclaimer
  13. 9About the Author

3.2 Design Considerations

The power design for a hand-held ultrasound equipment is complex and has a lot of system level challenges associated with it. All these challenges comes primarily due to the small size of the complete solution. Achieving high efficiency in low power rails with fixed synchronize frequency operation is the key care about since losses in the form of heat will increase the temperature of the board. Typically there is no cooling mechanisms employed in the end equipment due to its compact portable nature. Following are the key design considerations in the smart probe power solution.