Hello Together,
I've got a question about the Motordriver DRV8302. Exactly about the current protection OCP.
At the OC_ADJ I set the voltage to 200mV. My FET's at the H-Bridge have a RDSon around 15mOhm(Datasheet).
Now should the Driver Protection shut down the FET, when the current trough the FET bigger than 13 Ampere is.
The Driver Protection shut down to early. When the current nearly at 4 Ampere is.
I have also a shunt resistor in my circuit. This 50mOhm shunt resistor shouldn't have any influence to the current Protection(Datasheet)
Is this really true? or have the shunt also an action to the OCP?
Also possible is a problem with switching my FET. I use the PSMN014-60LS and switch with 4kHz.
The reference voltage OC_ADJ switching also at the moment. The DRV8302 have an OC sensing response time of 1.5us.
After 1.5us the voltage OC_ADJ is a little bit floating. Maybe is this floating the reason for the protection.
I thank you for an Answer and I apologize for my average english.
Nick Zwahlen