trying to understand BJT... Someone please assist
Firstly, please can someone orient the transistors in spice so it's easier to understand..Thanks
Did not try to make the push pull better as was only interested in seeing the amplifier part
:
Tried to make the circuit...Result is different from spice and not sure I made a mistake...
The voltage at base of Q1 was same as at base of Q2 (feedback yh? Always good to see it checks out ) but now the voltage at the output of the push pull is about -10v which is no good...Increasing R3 reduces the voltage...What am I missing??
Removed Q4 and Q5 and used 1mA on Q1 and connected collector of Q2 to -12V : here everything checks out..voltage at ..Gain was about 100....Just trying to use Q4 and Q5 (it is called active mirror in book) : just testing but not working properly
Using the active mirror, voltage at base of Q1 and Q2 was about 5v...Without the mirror, using current source on Q1, voltage at both bases was about 1V
Thanks
Firstly, please can someone orient the transistors in spice so it's easier to understand..Thanks
Did not try to make the push pull better as was only interested in seeing the amplifier part
:
Tried to make the circuit...Result is different from spice and not sure I made a mistake...
The voltage at base of Q1 was same as at base of Q2 (feedback yh? Always good to see it checks out ) but now the voltage at the output of the push pull is about -10v which is no good...Increasing R3 reduces the voltage...What am I missing??
Removed Q4 and Q5 and used 1mA on Q1 and connected collector of Q2 to -12V : here everything checks out..voltage at ..Gain was about 100....Just trying to use Q4 and Q5 (it is called active mirror in book) : just testing but not working properly
Using the active mirror, voltage at base of Q1 and Q2 was about 5v...Without the mirror, using current source on Q1, voltage at both bases was about 1V
Thanks
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