1overcosine_c:
Connecting it differently from what the datasheet says is not going to work
What exactly am I connecting wrong? The datasheet says VBOOT is an "overvoltage input to drive the upper DMOS" - should this not go to VS?
You need to look at this:
http://www.st.com/st-web-ui/static/active/jp/resource/technical/document/application_note/CD00004062.pdf
I'm hooking this up to one of those hobby aircraft motors (a fairly small one) that isn't going to draw nearly the 5 amps the thing is supposed to give, especially since it's not under any load.
I did common the grounds and have a 470uF cap between the supply and ground, and I will use 4.7k resistors - I think this caused the overvoltage.
My schematic: Imgur: The magic of the Internet
This chip is not up to driving a RC brushless motor, which have extremely low winding
resistance, this is doomed to failure. Typical RC ESCs have internal switch resistances
of 0.002 ohm or less and need it. This chip has a switch resitance of 0.3 ohms, over 100
times larger. A general rule of thumb is that the switch resistance should be < 10% of
the load resistance. Thus don't try driving a motor with less than 3 ohm winding
resistance with this chip for satisfactory behaviour. Even small RC brushless motors
have tiny winding resistances and will probably blow this chip.