I made a couple fo measurements focused on the OCP mode triggering.
The startup OCP level calibration seems right, OCP voltage level is about 57 mV (5k6 resistor)
Waveforms on SW pin 8:
The whole group of pulses
The detail of the low MOSFET switching, voltage drop is about a few mV, so in the limit
Detail of the last 6 pulses in the group of pulses - the higher voltage level maximum drop is about 750 mV, it seem that the HDRV driver cannont full open the higher MOSFET at the end
It confirms the previous waveform from SW pin, for some unknow reason the voltage on HDRV gradually falls from 14,4 V to the minimum od 12,9 V before the controller stops the switching
The whole group of pulses
The detailed upper part - the maximums of pulses, there is a voltage drop of about 1,3 V at the end
The detail of the last 6 pulses - there can be seen the slowing down of the rising edge
HDRV voltage relative to the input voltage - upper MOSFET drain, HDRV is gradually falling, driver cannot open the MOSFET
The SW voltage compared to the input voltage
Comparing the BOOT to SW voltage - when the upper MOSFET is ON, both voltages are the same
Has someone the idea why the high MOSFET drivers gradually fails to switch?