TIDT244 July   2021

 

  1. 1Description
  2. 2Test Prerequisites
    1. 2.1 Voltage and Current Requirements
    2. 2.2 Required Equipment
  3. 3Testing and Results
    1. 3.1 Thermal Images
    2. 3.2 Efficiency and Power Dissipation Graph
    3. 3.3 Efficiency and Power Dissipation Data
    4. 3.4 Current Regulation
    5. 3.5 Voltage Regulation
  4. 4Waveforms
    1. 4.1 Start-up
    2. 4.2 Switch Node
    3. 4.3 Output Voltage Ripple
    4. 4.4 Current Loop to Voltage Loop Transition
    5. 4.5 Voltage Loop to Current Loop Transition
    6. 4.6 Bias Voltage Start-up
    7. 4.7 Bias Voltage Switch Nodes
    8. 4.8 Output Current Sense Signal

4.8 Output Current Sense Signal

The average of the MB CHG ISNS signal (on TP1) can be used to monitor the output current of the power supply. The following figures show the signal shape for varying output conditions.

GUID-20210611-CA0I-DB2Z-5PRB-13LMHT8X30DD-low.pngFigure 4-15 VIN = 400 V, VOUT = 400 V, IOUT = 2 A.
I_mean = 2.03 V (500 mV/DIV, 4 µs/DIV, BWL = 20 MHz)
GUID-20210611-CA0I-JT5V-QP1M-WLFQ07BDSMSC-low.pngFigure 4-16 VIN = 400 V, VOUT = 400 V, IOUT = 500 mA.
I_mean = 511 mV (500 mV/DIV, 4 µs/DIV, BWL = 20 MHz)
GUID-20210611-CA0I-37P1-VQMZ-BC1C3Z6RSMGK-low.pngFigure 4-17 VIN = 400 V, VOUT = 400 V, IOUT = 100 mA.
I_mean = 107 mV (500 mV/DIV, 4 µs/DIV, BWL = 20 MHz)