I am working on an AVR controlled BLDC project, and in my search for info on how to setup the gate driver for my n-channel mosfets on the high side I came across this.
http://www.supertex.com/pdf/app_notes/AN-D26.pdf
and the datasheet
http://www.supertex.com/pdf/datasheets/HT0440.pdf

Anyhow, If I read this right, I can do away with quite a few components in my 3 phase driver section.
Does anyone have any experience with the HT0440 ?

Marvin

 

I've got some experience with it. Few little things i learnt from it.
It outputs very little current, a few microAmps, so expect some slow rise times

and even slower fall times on the output, so for a motor driver circuit, not sure

if this is a good choice unless slow switching is okay with you.
If you try and read the gate voltage with a multimeter or an oscillloscope, you

may read ~5V and think that it isnt working correctly and not fully turning on the

FET with a nice 10V gate-source voltage, but its just the impedence of the

measuring instrument weighing it down, so you'll just have trust that it is

actually outputing 10V. And I know the datasheet specifiys a maximum of 1mA

current for the input signals, but no min or avg...i think i tried a couple

hundred microamps, and that wasn't enough. So aim for the 1mA and measure the

input voltage to make sure its the voltage you were aiming for (5V+ in my case).

Other than that, the part seemed to be working fine, it's cheap and pretty simple

which is why i chose it,and my application was more for a high voltage highside

switch where speed wasnt a c
oncern and it did the job. GOod luck

 

Thanks for the info. I have some that will be arriving tomorrow and I'll have them in testing by tuesday. If I can get them to work right I can save about 12-18 components from my board design.

So they have very little output current, what if I tried logic level fets instead of the standard ones. Would they possibly give better performance at the lower switching voltage levels?

 

These things work really good, except for the fact that they seem to be too slow for PWM or even BLDC motor commutation.
I can still think of a bunch of ways to use these, but not in a bldc setup.

 

Yeah, try using fets with smaller gate capacitance, that'll speed it up some. And yeah, they make for some simple solid state relay apps.