If you detect movement it'd be possible to know when the motor stalls which causes overcurrent and heating.
Reading the datasheet again, I guess you're right. That would indeed mean that there would be no warning for overload of the motor.
If the mechanical power demanded from the motor exceeds the set electrical power from the H-bridge controller, stall can occur, but the delivered current will still be limited by the VREF setting, most likely protecting the motor from overheating. Heat production in the H-bridge will increase, but whether or not that leads to ThermalShutDown depends on VREF setting and cooling conditions of the chip.
The user needs to introduce another check on the functioning of the motor as the motor current is not available to be used as an indicator.
Or: other H-bridges that allow for current measurement are available.
Forget the Vref. I don't think this driver is suitable for your needs. At least not for detecting (adjustable) overcurrent.
You can see from the datasheet that this driver is intended for use with 2 DC motors OR with 1 stepper motor:
The TB67H420FTG is a brushed DC motor driver with sense
resistor less current control. The internal H-bridge can be
controlled independently, as a two brushed DC motor driver
or a single stepping motor driver using the dual H-bridge
mod
Vref only comes into play with stepper motors. Stepper motors must be controlled by the current through the coils. And the current setting is done via Vref. This has nothing to do with ‘overcurrent’.
Good news! One seems to be bad and I smoked the other one. So i am getting new ones that better fit what I am doing.