Quick simulation question

i think most of us familiar with L10 amplifier see also schematic on picture

I have one application that I have primary rails of regulated supply to feed the first stages lets say up to the drivers and a lower rail very beefy to feed the output

Can one quick simulate for what is the maximum voltage to feed the input stage ?


  • L10 amplifier.jpg
    L10 amplifier.jpg
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Ironically, this one cannot be determined by simulation (which rarely represents breakdown voltage accurately) but requires old-fashioned studying of datasheets instead. I think the 2SD667/2SB647 are the bottleneck, being Vceo = 80 V parts and having to swing almost rail to rail. So roughly +/- 40 V max, or +/-50 for 667A/647A. In the latter case a fault condition with the output pulled to V+ may still destroy Q6 (a 65 V part) and/or C4.

Ian Finch

Paid Member
2010-04-11 4:22 am
Coffs Harbour, NSW
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