I have an application where the DRV8860 is being used to activate some solenoid valves. VM = 24V and is fed to the DRV8860 through a high-side switch (TPS1H100).
We are trying to understand what happens if the 24V voltage feeding the switch and the DRV8860 and solenoids is disconnected. (other logic controls remain such as Enable). There is a couple hundred uF of bulk capacitance on the VM supply between the switch and the DRV8860 + solenoids.
My assumption is that as the VM voltage falls, eventually the DRV8860 will disable all outputs (UVLO = 8.2V). Any energized solenoids will begin to recirculate current through the freewheeling diodes and eventually decay to zero. The DRV8860 OUT voltage for an active solenoid would rise to be about 0.9V above VM voltage (which is falling). The VM voltage will continue to fall as the caps discharge.
Is this response correct?
