Cheers for the quick reply!
The Vcc _must_ be supplied with a regulated 5V - anything above 7V will destroy the chip (abs max ratings). It
also need standard logic decoupling of course.
Yep, I've got Vcc at a regulated 5v with appropriate local decoupling etc.
Heat dissipation to a first approximation is about 1 to 1.5 times the current - the saturation voltage of the darlington
times its current.
However since this is a high voltage switch there will be significant power dissipation on switching (switch off takes
upto 25us) - if the output voltage is 100V at 6.5A then a smooth ramp-down could dissipate about 8mJ, or 8W at
1000Hz... Output voltage depends on the inductor being switched. Only at switch-off will there be a high
voltage (inductive load).
Ah, I think something has just clicked with me - this is a sinking IC, not a sourcing IC - hence the lack of a battery voltage connection to the chip.
As for 'output voltage', are you referring to the voltage seen on the HVc pin when the load is switched off, i.e. the inductive spike?