JAJU873 August   2020

 

  1.   概要
  2.   リソース
  3.   特長
  4.   アプリケーション
  5.   5
  6. 1 System Description
    1. 1.1 Medical Respiratory Systems
    2. 1.2 Respirator System Components
    3. 1.3 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 Brushless DC Motor (BLDC)
        1. 2.2.1.1 DRV8323RS BLDC Motor Driver Design Calculations
        2. 2.2.1.2 BLDC Motor Driver Circuit
      2. 2.2.2 Solenoid Valve Drivers
        1. 2.2.2.1 DRV8847 Solenoid Driver Design Calculations
        2. 2.2.2.2 Solenoid Driver Circuit
      3. 2.2.3 Power Tree Architecture
        1. 2.2.3.1 Input protection - overvoltage and reverse voltage
        2. 2.2.3.2 LM5122 Boost Design Calculations
        3. 2.2.3.3 LMR33630 Buck Design Calculations
        4. 2.2.3.4 Secondary Power Stage – TPS62840 3.3V Buck
        5. 2.2.3.5 Secondary Power Stage – TPS7A02 3.3V LDO
        6. 2.2.3.6 Power Tree Circuit
    3. 2.3 Highlighted Products
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware and Software Requirements
    2. 3.2 Test Setup
      1. 3.2.1 Hardware Configuration
      2. 3.2.2 Software Configuration
    3. 3.3 Test Results
      1. 3.3.1 Motor Test Result
      2. 3.3.2 Valve Test Result
      3. 3.3.3 Power Tree Test Result
      4. 3.3.4 Key Test Summary
  9. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
    2. 4.2 Documentation Support
    3. 4.3 サポート・リソース
    4. 4.4 Trademarks
  10. 5About the Author

3.3.3 Power Tree Test Result

The following power tree tests were conducted:

  • Efficiency
    • LM5122
    • LMR33630
    • DRV8323RS’s Integrated Buck
    • TPS62840
  • Thermal distribution imaging

Efficiency

The efficiency plots for the LM5122, LMR33630, DRV8323RS, and TPS62840 devices are shown from Figure 3-23 to Figure 3-26, respectively.

GUID-20200804-CA0I-8XVF-SQKX-9J5D1JQG3KNM-low.gif Figure 3-23 LM5122 Efficiency, Vout = 14 V
GUID-20200804-CA0I-WHFC-S6CF-GCFH1QT5L1QD-low.gif Figure 3-24 LMR33630 Efficiency, Vout = 12 V
GUID-20200804-CA0I-5CDK-4NFF-FXNSH4BHM9CP-low.gif Figure 3-25 DRV8323RS Integrated Buck Efficiency, Vout = 4 V
GUID-20200804-CA0I-GXVV-6D9X-PDBLK83PBL83-low.gif Figure 3-26 TPS62840 Efficiency, Vout = 3.3 V

Thermal Distribution Imaging

The condition for the thermal image in Figure 3-27:

  • Vin = 12 V
  • Pin = ~4.5 W
  • BLDC motor inactive
  • DRV8847 cycling 42 ms
GUID-20200801-CA0I-9WCV-G8ZS-26JZ4TH13QN8-low.png Figure 3-27 Thermal image for 4.5-W input

The condition for the thermal image in Figure 3-28:

  • Vin = 12 V
  • Pin = ~6 W
  • BLDC motor at 2 kRPM
  • DRV8847 cycling 800 ms
GUID-20200801-CA0I-MMHZ-VJQP-RGKZKT2FKSMZ-low.png Figure 3-28 Thermal image for 6-W input