No sign of life from VNH2SP30

Your VNH2SP30 on the carrier board looked perfect for my robot application, but I’m having some trouble getting it to work in my test circuit. I think I am feeding it all the right inputs, but I get absolutely nothing from the motor outputs. (I only have a generic multimeter, so if it’s giving a few mV I’ll never know.)

My test setup is a PIC toggling the A and B inputs and switching between 100% and 50% PWM duty cycles. Standing in for a real motor is a bicolor LED. The error pins are disconnected, and CS is hooked up but I haven’t written any code for it yet. From debugging LEDs and meter readings I can tell that A and B are alternately being given +5V and 0 (definitely no “brake” conditions), and the PWM is working fine too. I’ve checked all my connections, tested the outputs directly to see if my LED was blown, and substituted +5V on the PWM pin to see if that was the culprit. In the test circuit everything is on the same 5V supply, so ground is common. I tried using a separate 5V supply for the “motor” just in case, but that does nothing as expected.

I can’t think of what to check next. Do you have any suggestions as to what I might be doing wrong? In my less-than-illustrious electronics experience I’ve found that the problem is usually something completely stupid, so please don’t make any assumptions about my intelligence. :wink:


The operating supply voltage is from 5.5 V to 16 V, so 5 V probably isn’t enough.

- Jan

I just gave it 6V and it works perfectly… Thanks for your help.