Hi all,
I've been trying to implement a system (due to UL requirement for safety) where I need to brake a motor (max rpm=4000). By modifying the Motor Control library I' managed to add braking by overwriting "R3_1_LowSideBrake" to perform a full brake on the motor using the Low-Side Fets.
My next step is actually braking the motor only using HW logic. For that I've ORed a switch with CIN pin to disable the motor driver with the hopes I could program the Timer Break to enable low side FETS (by setting the IDLE output of low sides) but without much success.
Below is the schematic of what I did. Signals from R509/R510/R511 comes from current sense resistors to detect the Overcurrent fault.
After re-reading the datasheet again, it seems that the driver itself disables all outputs and doesn't really allow for braking to happen. Below is the reference of this statement:
https://www.st.com/resource/en/datasheet/stspin32f0601.pdf page 18,
"If the impulse on the CIN pin is higher than VREF and wider than tFCIN, the SmartSD logic is triggered and immediately sets all of the driver outputs to low-level (OFF). (...)"
Notes:
- The usage of brake resistor is out of the question for the moment, since it implies adding a larger cost to the BOM and are bulky.
Thank you & Awaiting feedback.
Cheers.
