Tool/software:
Hello,
We have used this part for many years to drive a small DC/DC converter. The inputs are complementary square waves without deadtime created from a 555-timer. According to the datasheet, 220 ns of deadtime should be automatically inserted to prevent shoot through. This way, the outputs are complementary square waves with deadtime. This circuit has worked flawlessly for many years with +100k units produced.
After last PCN (20231115001.1), this circuit does no longer work. It seems that the deadtime is gone and that the we get a shoot-through in the bridge. This trips the overcurrent protection and the circuit tries to restart every 3 ms.
Old circuit (before PCN)
~220 ns deadtime in accordance with datasheet. Circuit works fine.
OUT1 (Blue)
OUT2 (Green)
voltage over shunt resistor (Red).
New circuit (after PCN)
There is no or too little deadtime. Shoot through in bridge can be seen. Shoot through causes overcurrent protection to trip if VM is raised to nominal voltage of +13V.
OUT1 (Blue)
OUT2 (Red)
voltage over 100 mOhm shunt resistor (Green).
According to the PCN, the change should not have impacted form fit or function.
Have you changed the design and removed the deadtime?
Best regards,
Filip
