Devices we may be using in a few years for higher switching speed Class D

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Jump to Latest
I

iand

Member
Joined 2007
bwaslo said:
http://www.irf.com/product-info/ganpowir/introganpowir.pdf

Is the limit for Class D switching speed/rate the FETS, or other devices?
Or is switching faster even a good thing to go after?
Click to expand...

Faster switching reduces loss at higher clock frequencies, which opens up a lot of possibilities for efficient power D/A conversion (like Zetex DDFA which uses 850kHz) -- for "conventional" class D amps there's little advantage in using more than 400kHz.

It's not clear from the article but it looks as if there's no body diode, which means a much faster separate diode could be used to reduce switching loss -- the best 200V silicon MOSFETs have trr around 100ns, discrete diodes are up to 4x faster.

So we could end up with half the power losses even if the switching frequency doubles.

The 200V devices aren't available yet, though :)

Ian
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Top Bottom