>Transistor Matching<

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Rickrrc
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Joined: Thu Feb 25, 2021 12:25 am

>Transistor Matching<

Post by Rickrrc »

Many power amplifiers use a differential transistor pair at the front end of the circuit. When replacing these you need to use a matched pair of transistors. I’ve seen people using the Peak Atlas tester for this but my understanding is that it tests at such a low current the results may not be relevant for matching. I’ve seen people making circuits to measure the differential output voltage between two transistors. Some use an AC circuit and some use a DC circuit. For this method, I’m not sure what voltage differential signifies a proper match. Also a little confusing to me is that I thought the matching was for hfe but these circuits are measuring voltage. Can anyone help me understand what would be considered the gold standard for finding a matched transistor pair. For the purpose of this discussion let’s assume most hobbyists don’t have access to proper curve tracing equipment. Please share your thoughts on this as I find it to be a very interesting topic
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