Other Parts Discussed in Thread: DRV8873, , SN74LVC8T245-EP
Tool/software:
Subject: Urgent Help Needed: Issues with DRV8873-Q1 H-Bridge Driver in Project
Hi Team,
We are currently integrating the DRV8873-Q1 H-bridge driver from TI into our project as an alternative to the VN771K for obsolescence management. Each board uses 8 H-bridge drivers, and we are encountering several issues during board bring-up. I’ve attached the board schematic, connection details, and datasheets for your reference.
Here are the issues we’re facing:
Shorting of DVDD and GND Pins: We are observing a short (around 5.6 ohms resistance) between the DVDD and GND pins in the H-bridges. This issue has been noted in 15 units so far.
Level Translator IC Failure: The SN74LVC8T245-EP level translator IC has failed while driving the load.
Output Voltage Spike: A spike with an amplitude of nearly 28V is observed at the output side of the IC when the load is connected and driven.
nFault Pin Behavior: The nFault pin goes low after approximately 25 seconds of power-up. Should we reset the sleep pin to clear this fault?
Damage to DVDD Due to VM and GND Short: If the VM and GND pins are shorted due to glitches at OUT1 and OUT2 (Ref:picture1:- glitch observed at outputs, picture 2: waveform at OUT1 and OUT2 pins), could this damage the DVDD output? If so, what is the maximum duration of such a glitch that can cause damage? The chip is configured in the hardware PWM mode and driving the OUT1 and OUT2 with 600 ms time gap
e2e.ti.com/.../HBD-SCH.pdfe2e.ti.com/.../Relay-datasheet.pdf
We are looking for suggestions on debugging these issues and ensuring the boards are ready for production .
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Thank you for your assistance!