Matching IRFP240 for Alpeh2

i have a fool problems about to Matching IRFP240 for Alpeh2

for Alpeh2 have 24 pcs IRFP240(12 pcs each channel)
and each channel 6pcs(Q6-Q11) are for current source
6pcs(Q12-Q17) for output drains
total have 4 group X 6 pcs

so when i try to matching IRFP240
i need to match totally 24 pcs for nearest Vgs?
or just matching 4 group 6pcs ??

thanks,
 

BrianGT

Retired diyAudio Moderator
2002-01-21 2:42 pm
near Atlanta, GA
www.chipamp.com
The reason that you are matching them is because you have 2 groups of 6 devices running in parallel for each channel. It is important that the 6 devices are matched themselves, but it doesn't make much difference if the 2 groups are matched to each other.

I bought 124 IRFP240 and managed to get them matched up quite well. Most sets were well within 0.01 Vgs.

--
Brian
[email protected]