MPQ6528 - OC_REF voltage value

Motor Drivers/Sensors
1

Hi,
How can I calculate the voltage value on the OC_REF pin?
Is there a formula?

IC: MPQ6528
Evaluation Board: EVQ6528-V-00A

Thank you

2

Hello Marso,

To set OC_REF, you would use a voltage divider from any voltage source and drop it down to 0.125V - 2.4V.

On the EVBQ6528, set the divider using R7 and R8 from the VDD value you are using.

Regards,
Vinh Tran

3

Hello Vinh,
Thank your for your reply.

The thing I didn’t understand is how to calculate the voltage divider value in order to have a maximum current of 30A.

Regards

4

Hello Marso,

OC_REF is used for SCP.

To get 30A OCP, you will need to set the R_LSS resistor. Following the example set in the DS: “For example, when a 50mΩ resistor is used, a 10A current would cause a 500mV drop, triggering OCP”.

So, for a 30A limit, you will need ~0.016666mOhm resistor.

Regards,
Vinh Tran

5

Hello Vinh,
ok, now it is clearer for OCP, but what voltage value should I put on OC_REF?

Regards,
Marso