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No Output from EVALPWD13F60 board

rmshub
Associate II

We applied VCC1 & VCC2 @12V , VS = 110V, HIN1=3.3V, LIN2=3.3V (HIN2=GND & LIN1=GND) Measured output voltage across OUT1 & OUT2. However, no output voltage is observed. And also tried HIN2=3.3V, LIN1=3.3V (HIN1=GND & LIN2=GND). Here also same no output behavior.

Could you please check this issue as high priority.

1 REPLY 1
fabbri.fabio
Associate II

To properly turn on high side MOSFET (the one drive by HIN), the bootstrap capacitor (the one between BOOT and OUT, supplying the floating structure) shall be charged first.

To charge the capacitor thru the integrated bootstrap diode, a low resistance path shall be placed between OUT to GND. This is normally accomplished in these bootstrap architectures by turning on the low side MOSFET asserting the LIN input for the time required to charge the capacitor.

This is the reason why you need to assert the LIN pin before asserting HIN pin for proper operation.

For example, with the integrated diode and the capacitor used in the eval board (220 nF) a time in the range of 100us is sufficient.