Q:
What are potential causes for a damaged Trinamic motor driver IC (burnt near pins)? Is the IC susceptible to ESD?
A:
Trinamic driver ICs use a multi-chip construction, which has 8 discrete MOSFETs driving the motor. Each MOSFET is cooled by each two pins. The MOSFETs can be damaged by overheating (>175°C, or cyclic above 150°C) or by overvoltage exceeding the max. ratings by more than 4V as well as by ESD events. The overtemperature detection cannot react to individual MOSFET temperature. It just measures the core chip temperature, which is more an indication of overall and the environment temperature.
With this, there are multiple potential conditions leading to IC defect of this kind (most probable to seldom):
Right after production:
* Error in test equipment leading to short circuit at motor connector or wrong attached motor
* Hot plug / pull of motor connector
* Hot plug / pull of supply voltage (can lead to overvoltage)
* ESD (most probably prior to soldering of the device)
* bent pins not fully soldered
After some time
* Manual fast turning of motor while device is switched off (or on) leading to the supply being pumped up above voltage limits (apply suppressor diode on board supply)
* Fast deceleration of motor from a high velocity leading to supply voltage pumped up above supply voltage limit
* Application failing to reduce current in standstill can lead to overheating of parts of the output driver
After long time of operation
* Insufficient cooling of the IC - some of the MOSFETs operating above maximum temperature for long time. Switch the IC to lower overtemperature threshold for better detection of heat accumulation
* Insufficient design of PCB not following datasheet guideline. Please ensure symmetric layout and cooling of all relevant pins.