these currents seem a bit odd.
Iq1=45mA results from Vbeq4=675mV
Iq2=62mA results from Vbeq3=930mV
Surely the Vbe of the output pair passing 1.7A can be very much closer than that. 930mVbe sounds like a faulty output transistor.
The drivers should pass almost identical bias current if the outputs' Vbe match @ operating (bias) current.
With near identical Ic then matching hFE results in near identical Ib. Then your mismatched diode current problem goes away.
Iq1=45mA results from Vbeq4=675mV
Iq2=62mA results from Vbeq3=930mV
Surely the Vbe of the output pair passing 1.7A can be very much closer than that. 930mVbe sounds like a faulty output transistor.
The drivers should pass almost identical bias current if the outputs' Vbe match @ operating (bias) current.
With near identical Ic then matching hFE results in near identical Ib. Then your mismatched diode current problem goes away.
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mind that it's solely a sim, so the mismatch is in the models (probably reflecting reality). I'm open for suggestions for output trans.
However, Vbeq4 is 420mV, Vbeq3 is 670mV, Ibq3 is 17,9mA, Ibq4 is 17mA acc. to the sim with the previously given Ic(Q1, Q2).
If I use the models of the mje's for the output Q's the biasing is now equally 45mA for Q1 and Q2, but the diff. between D1 and D2 stays.
Rüdiger
However, Vbeq4 is 420mV, Vbeq3 is 670mV, Ibq3 is 17,9mA, Ibq4 is 17mA acc. to the sim with the previously given Ic(Q1, Q2).
If I use the models of the mje's for the output Q's the biasing is now equally 45mA for Q1 and Q2, but the diff. between D1 and D2 stays.
Rüdiger
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