TIDUF26 june   2023 BQ24072 , LMR36520 , TLV62568 , TPS2116

 

  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 24 VAC to DC Rectification
      2. 2.2.2 eFuse Protection
      3. 2.2.3 5-V Rails
        1. 2.2.3.1 LMR36520 Voltage Rail
        2. 2.2.3.2 USB Power Input
      4. 2.2.4 Power Source ORing
      5. 2.2.5 Battery Management
      6. 2.2.6 3.3-V Power Rail
      7. 2.2.7 Power Rail Current Sensing
      8. 2.2.8 Backlight LED Driver
      9. 2.2.9 BoosterPack Overview
    3. 2.3 Highlighted Products
      1. 2.3.1 LMR36520
      2. 2.3.2 TPS2116
      3. 2.3.3 TLV62568
      4. 2.3.4 INA2180
      5. 2.3.5 TPS92360
      6. 2.3.6 TPS2640
      7. 2.3.7 BQ24072
  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  24-VAC Start-Up and Shutdown
      2. 3.3.2  USB Start-Up and Shutdown
      3. 3.3.3  ORing
      4. 3.3.4  LMR36520
      5. 3.3.5  TLV62568 Transient Response
      6. 3.3.6  BM24072 Transient Response
      7. 3.3.7  TLV62568 (3V3 Power Rail)
      8. 3.3.8  LMR36520 (LMOut Power Rail)
      9. 3.3.9  BM24072 (BMOut Power Rail)
      10. 3.3.10 Reference
        1. 3.3.10.1 TLV62568
        2. 3.3.10.2 LMR36520
  10. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
    2. 4.2 Tools and Software
    3. 4.3 Documentation Support
    4. 4.4 Support Resources
    5. 4.5 Trademarks
  11. 5About the Author

3.2 Test Setup

Several test points are made available for each process on the PCB. However, when performing ripple, transient, and efficiency tests, do not use the break out test points due to parasitic noise. Instead, measure the output, input, or other point of interest as close to the IC pins as possible. An example of a transient test setup is shown in Figure 3-1 that uses a barrel wire to GND technique and the current-carrying wires are soldered directly onto the output capacitor of the DC-DC being tested. These current-carrying wires are connected directly to a programmable electronic load and the current is measured through a current probe as shown in Figure 3-2. When performing efficiency plots, separate wires from the current-carrying wires must be used, as shown in Figure 3-3 to avoid inaccurate measurements due to line voltage drops.

GUID-20230607-SS0I-NZJC-PWXS-0MPGCHWV8JRW-low.jpg Figure 3-1 Soldered Output Wires and Scope Probe and Barrel Test Setup
GUID-20230607-SS0I-KLKH-XJ6P-VZFSDB2QLST6-low.jpg Figure 3-2 Current Probe and Electronic Load Test Setup
GUID-20230607-SS0I-RMM9-X9BN-P9DQPPBQKW4M-low.jpg Figure 3-3 Separate Sensing and Current Carrying Wires Test Setup