SLUU381B September   2009  – February 2022 TPS51220A

 

  1.   Trademarks
  2. 1 Introduction
  3. 2 Description
    1. 2.1 Typical Applications
    2. 2.2 Features
  4. 3 Electrical Performance Specifications
  5. 4 Schematic
  6. 5 Test Setup
    1. 5.1 Test Equipment
    2. 5.2 Recommended Test Setup
    3. 5.3 List of Test Points
  7. 6 Test Procedure
    1. 6.1 Line/Load Regulation and Efficiency Measurement Procedure
    2. 6.2 Output Ripple Test
    3. 6.3 Measuring Improved Light Load Efficiency
    4. 6.4 Control Architecture and OVP Select
    5. 6.5 Overcurrent Trip Level and Output Discharge Select
  8. 7 Performance Data and Typical Characteristic Curves
    1. 7.1 Efficiency
    2. 7.2 Load Regulation
    3. 7.3 Bode Plot
    4. 7.4 Transient Response
    5. 7.5 Output Ripple and Switch Node
    6. 7.6 Turn-On Waveform
    7. 7.7 Turn-Off Waveform
  9. 8 EVM Assembly Drawing and PCB Layout
  10. 9 List of Materials
  11. 10Revision History

6.1 Line/Load Regulation and Efficiency Measurement Procedure

  1. Ensure the switches S1 (EN1), S2 (EN2), and S3 (EN) are in the “OFF” position.
  2. Ensure the shunt jumper are set as follows, see Section 6.3, Section 6.4, and Section 6.5 for details on how to change these settings:
    1. JP1 (SKIPSEL1): jumper 3 pin to 4 pin (AS)
    2. JP2 (FUNC): jumper 1 pin to 2 pin (CMODE_ON)
    3. JP3 (TRIP): jumper 7 pin to 8 pin (LV_D-ON)
    4. JP4 (SKIPSEL2): jumper 3 pin to 4 pin (AS)
  3. Set the DC power source current limit to 10 A. Increase VIN voltage from 0 V to 8 VDC. V3 should be used to verify VIN.
  4. Measure VREG3 (TP9) voltage using V4. It should be between 3.2 V and 3.4 V.
  5. Set S3 (EN) to “ON” position. Measure VREG5 (TP5) voltage using V5, it should read between 4.9 V and 5.1 V. Measure VREF2 (TP15) voltage using V6, it should read 1.98 V to 2.02 V.
  6. Make sure electronic load #1 is set to sink 0 A. Set S1 (EN1) to “ON” position, S3 remains in “ON” position.
  7. Record VOUT1 voltage using V1, IOUT1 current, VIN using V3 and input current from source.
  8. Increase electronic load #1’s current in 0.5-A steps from 0 A to 8 A, Record VOUT1 voltage using V1, IOUT1 current, VIN using V3 and input current from source for each step.
  9. Set input voltage to 20 V.
  10. Reduce the current of electronic load #1 from 8 A to 0 A, the current electronic load #1 in 0.5-A steps from 0 A to 8 A. Record VOUT1 voltage using V1, IOUT1 current, VIN using V3 and input current from source for each step.
  11. Similar technique can be used for VOUT2. Use S2 to enable VOUT2.