Multiple Aperture Window Discriminator

Thread Starter


Joined Oct 23, 2004
Hi guys,

I'm looking at the MAWD on the 3rd page of this link :

could somoene explain how this works ?

I understand that they are a bunch of comparators, but can someone explain the FETs ?

hers's what i understand,

once the first op-amp (V4 and Vin) goes HIGH ( ie: Vin > V4 ) , the fet is conducting, therefore, Vin appears at the positive terminal beign compared to V3 .... doesn't that mean that the output from the second opamp goes HIGH when the first condition is satisfied ( Vin > V4 ) AND Vin > V3 ?

Thanks guys

My apologizes this should have been posted in the General Electronics section


Joined Apr 20, 2004
If the compared voltages are each higher as you go down the chain, then the comparators work. If V4 is 1 volt, V3 is 2 and V2 is 3, presenting 2.5 volts at Vin will result in the top two comparators high and the bottom 2 low, meaning the input is between 2 and 3 volts.