SLIS175 November 2016 DRV8872-Q1
The DRV8872-Q1 device limits the output current based on the resistance of an external sense resistor on pin ISEN, according to Equation 1.
For example, if RISEN = 0.16 Ω, the DRV8872-Q1 device limits motor current to 2.2 A no matter how much load torque is applied. For guidelines on selecting a sense resistor, see the Sense Resistor section.
When ITRIP has been reached, the device enforces slow current decay by enabling both low-side FETs, and it does this for time tOFF (typically 25 µs).
After tOFF has elapsed, the output is re-enabled according to the two inputs INx. The drive time (tDRIVE) until reaching another ITRIP event heavily depends on the VM voltage, the back-EMF of the motor, and the inductance of the motor.