Customer:
I have a DRV84 driver with a damaged Zener diode (D2). After desoldering it, the driver still works as expected. Can I continue using it without the diode as long as I don’t connect the FAULT pin? Should I expect any further damage? Alternatively, could any other 3.3V Zener diode with similar dimensions work as a replacement?
Originally submitted via the contact form on soldered.com on 11 February 2025. Migrated to the forum for community visibility.
Soldered Support:
The driver will work without the diode if you don’t connect more than 3V3 to the SLEEP pin.
Customer:
I applied 5V to the SLEEP pin without realizing it was connected to D2, which fortunately caused no issues. I destroyed D2 by connecting FAULT to 5V directly, resulting in smoke from the diode. I assume any SMD 3.3V Zener diode will work as a substitute.
Soldered Support:
Looking at the schematic, the SLEEP pin is the one affected by the Zener diode. You can use essentially any Zener diode with a Vz of 3V3, which should be very common.
Customer:
I soldered in a new Zener diode (SOT-23, marked Z14). Everything works correctly now.