Trouble with VNH3SP30


I’ve been working with VNH3SP30 I bought from Pololu. I bought only the ICs and not the boards. I made my own board and I’m facing some major issue:

While running the motor driver for smaller motors which consume close to 500 mA, I face no trouble at all. But as soon as I move into a larger range of 1 Ampere motors or above, my VNH stops responding altogether. It pulls my inputs low, which is something beyond me. This means that if my input voltage is 5 Volt at Input A and GND at Input B, both are pulled down to ground (-0.3 volt actually). The board doesn’t heat up, doesn’t indicate in any way that there is any kind of thermal shutdown, but thats it.

Now the 5 volt input I gave above was from an Atmega 16, when I give it an output from a SMPS, the motor suddenly starts running perfectly. I’m thoroughly confused here…Could anyone help me out with schematics of their own boards/anyone who has worked on this particular IC, could you please tell me what to do next?


We have schematics of our carrier boards posted. Perhaps you can post your schematic (including power supply connections) and layout.

- Jan