AnsweredAssumed Answered

L6474 Charge pump low...only 5 volts

Question asked by kenny.larry on Jun 26, 2014
Latest reply on Jul 7, 2014 by Enrico Poli
I'm builting a mini drive using the L6474. Got it all working and it runs smooth, but the driver runs very hot and I measured the charge pump and the voltage is only 5volts p-p max (manual says it should be 10vp-p)

   The pump is running about 900K-1mhz but only swinging about 5 volts.  and when the motor is running slow, it goes as low as 3 .5 volts.  

 The slower you spin the motor the hotter  it gets, (very hot, over 100C) and when you speed it up it runs cooler.  Im guessing the upper mosfets aren't being fully turned on, generating the heat. 
 Any ideas ?