I recently received the LVDS motor controller, and I am concerned about having a voltage on VMot when there is no power supply hooked up to this pin. I am running this on a breadboard with a PIC18F452 sending the serial commands. I’m using a regulated power supply at 5V.
While running the controller with motors (dual motor mode) hooked up and 4.8V for the motor power supply, and ramping up the speed from 0 to 64, things start out good. As the motors freely spin up to speed, it gets to a point where the motors stop and the regulated power supply drops to 1.5V or so (I have the current limited and it seems as though the circuit is starting to draw too much current).
When I disconnect the motor power supply and motors, and then hook up a DVM to VMot, I notice there is a voltage reading on this pin. It will start out at about 5.7V and slowly drop as the motor speed is increased. Is there suppose to be this sort of voltage reading on this pin when nothing is connected to it?? Also, the LVDSMC and PIC are the only devices hooked up to the 5V powers supply.
I have the Micro LVDSMC and VMot is 0 when nothing is connected, if only it could handle the current draw from these motors, I’d just use this one.
Anyhow, I’ve been quite happy with the micro dual serial controllers so I’m hoping to get this LVDSMC going reliably.
Any help or input would be greatly appreciated.