[FAQ] DRV8316: How does the VREF/ILIM pin work?

How to put the device in current limiting mode or current sense amplification mode?

              The VREF/ILIM pin and the PWM mode the device is in determine if the device will be in in current limiting mode or current sense amplification mode. If the device is in PWM modes 2 or 4 and the VREF/ILIM pin is supplied an external voltage between AVDD/2 and AVDD/2 - 0.4 V then the device will operate in the current limiting mode. If the device is in PWM modes 1 or 3 and the VREF/ILIM pin is supplied an external voltage between 2.8 and AVDD V then the device will operate in the current sense amplification mode. Please refer to the table below for a condensed reference of this information.

How do I supply voltage to the VREF\ILIM pin?

The external voltage supplied to the VREF/ILIM pin can come from either the device’s AVDD pin output or an external voltage generator output pin. The VREF/ILIM pin’s input voltage should not exceed the voltage value for AVDD, which would typically be 3.3V – this is true regardless of whether or not the device is on or off.  

Can I switch the mode of the VREF/ILIM pin during device operation?

              This is possible, but should not be done when the device’s inputs/outputs are actively switching. For example, in the event that the user wants to reconfigure the system’s PWM-mode setting, they must first set INHx and INLx to LOW so that the outputs are not switching. The user can then update the voltage being input to the MODE and VREF/ILIM pins to update the PWM-mode and the VREF/ILIM settings, and then resume device switching operation afterwards.