2.1 MOSFET Driver Output Turns High if Power ON Sequence is not Appropriate
If power is applied to VDR before VDD has reached the minimum operating voltage a pulse of VDR voltage will appear on PDRV1 and PDRV2.
The pulse width can be sufficiently long to cause power switch turn ON and power train damage.
Workaround
Power up sequencing enabled by VDD is recommended to be used for VDR supply.
VDR must not be powered if VDD has not reached minimum operating voltage.
A recommended implementation for correct power up sequencing can be found in Schematic 1.
Resistor R is recommended to be below 3.3 Ω to make sure the voltage drop during switching does not cause driver undervoltage events. Further optimizations can be done based on the value of the selected decoupling capacitor.
If VDR needs to be supplied with a voltage higher than VDD, Schematic 2 is recommended to be used.
The Power ON Timing Diagram can be used as an example for correct power ON sequence. Timing recommendations can be found in Table 2-1.