VN9D5D20F what does "Reverse battery through self turn-on" mean?

[Dazai]

The datasheet for the VN9D5D20F lists "Reverse battery through self turn-on" as a bullet point under "Protection", while the VN9D5D20FN datasheet does not.  This appears to be one of the major differences between the two parts, but I do not understand what it means and was unable to find a description in the VN9D5D20F datasheet.

What does "reverse battery through self turn-on" do?

VN9D5D20F:

VN9D5D20FN:

VN9D5D20F - 4-channel high-side driver with 24-bit SPI interface for automotive applications - STMicroelectronics

VN9D5D20FN - 4-channel high-side driver with 24-bit SPI interface for automotive applications - STMicroelectronics

[MBONA.1 · Accepted solution]

ciao Dazai, you're right! the only difference between the VN9D5D20FN and VN9D5D20F is the presence of the reverse battery through self-turn on (in the VN9D5D20F). This feature is intended to avoid high power dissipation during reverse battery polarity. In particular, the device is able to detects when the battery is connected with reverse polarity and in this case, the internal Mosfet automatically turns on and not trigger the body diode of the device. Once the battery polarity is corrected, the device exits protection mode, and the driver resume normal operation. NB: it is important to connect the pin PWM_CLK of the device in reverse battery polarity otherwise the device is not able to self turns on. I hope this explanation is clear.BR, Marika