Burned Source Driver - Noise Spikes from Relay Coil
I am trying to figure out what is causing an Allegro A2982 source driver to burn up.
The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
The rail of the source driver (Vs) is 9 V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. Note: I am using a differential probe to measure the voltage across the coil.
Is it a valid concern that:
- This voltage spike is causing damage to the source driver?
- The 9V supply may see the voltage spike and cause damage?
- The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
If the spike is causing damage, is there a way to reduce or mitigate the spike?
The circuit is used to turn off a motor. Below is a scope capture. The squared area in red is when the motor turns off. The output of the relay controls an ON/OFF signal (3.3V or GND). Note: The relay coils are located near the motor. Three outputs of the source driver are used to drive three separate relay coils.