Buck converter:
Start-up testing
Measure R between Vin and GND, Vin and SW, SW and GND, Vout and GND
Measure R of feedback resistors, frequency select resistor
Set up a start up test, 1 probe on SW and 1 probe on Vout. Set up oscilloscope to measure waveforms on SW and Vout and make sure to set trigger to single. Then quickly turn on and off the power supply. Hopefully the waveforms show that buck converter works or explain why it doesn’t work.
Load regulation
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Load transient
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Set up: Oscilloscope AC coupled, 1GHz bandwidh
Over current protection
The video below is testing the over current protection feature of the buck chip only, the PCB only has the buck circuit assembled at this point. The e-fuse chips and pwm buffer are not populated at this point yet.
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