How to drive MOSFETs fast

[Bruce Varley]

This might be of use to others that are living in a cave electronically
speaking, like me.

Recently spent a day trying to drive MOSFETs fast using bipolars. I'm after
a switch time of < 1uSec, and nothing I tried came close. In the end I
googled driving mosfets, and up came lots of ads for MOSFET drivers. Turns
out these things are a dream solution to the problem. They'll switch a half
bridge in a few tens of nanoseconds, with configurable deadtime. They'll
handle a bridge with both devices N-channel, and best of all, they'll work
with a rail that can be up to hundreds of volts. AND they can be obtained in
DIP-8 package. AND, they aren't expensive.

 

[Electronworks.co.uk]

"Bruce Varley" <bxvarley@weastnet.com.au> wrote in message
news:QYGdnblAcfcCkMrXnZ2dnUVZ8jGdnZ2d@westnet.com.au...

This might be of use to others that are living in a cave electronically
speaking, like me.

Recently spent a day trying to drive MOSFETs fast using bipolars. I'm
after a switch time of < 1uSec, and nothing I tried came close. In the end
I googled driving mosfets, and up came lots of ads for MOSFET drivers.
Turns out these things are a dream solution to the problem. They'll switch
a half bridge in a few tens of nanoseconds, with configurable deadtime.
They'll handle a bridge with both devices N-channel, and best of all,
they'll work with a rail that can be up to hundreds of volts. AND they can
be obtained in DIP-8 package. AND, they aren't expensive.

Just make sure you supply them with a low impedance source - good thick

power supply rail and good ground. Decoupling write next to the Vcc and GND
pins is always advisable - as recommended in the datasheet.

If you want to kick 4A into the gate of a MOSFET, that current has to come
from somewhere. If the supply to the chip cannot provide it, your fantastic
MOSFET driver will not be as good as advertised..

-
Bill Naylor
www.electronworks.co.uk
Electronic Kits for Education and Fun

 

[Eeyore]

Bruce Varley wrote:

This might be of use to others that are living in a cave electronically
speaking, like me.

Recently spent a day trying to drive MOSFETs fast using bipolars. I'm after
a switch time of < 1uSec, and nothing I tried came close. In the end I
googled driving mosfets, and up came lots of ads for MOSFET drivers. Turns
out these things are a dream solution to the problem. They'll switch a half
bridge in a few tens of nanoseconds, with configurable deadtime. They'll
handle a bridge with both devices N-channel, and best of all, they'll work
with a rail that can be up to hundreds of volts. AND they can be obtained in
DIP-8 package. AND, they aren't expensive.

Depending on the application they're very likely emitter followers. These can
charge Cg very quickly.

Graham


--
due to the hugely increased level of spam please make the obvious adjustment to
my email address