Hello everyone,
I'm working on something wich require a differential to differential amplifier. I do not want to use op amps for this, only discrete components.
I have tried to use various versions of the common long tailed pair, but the high gain causes it to behave like a comparator. Normally you loop back a portion of the output to one of the inputs (i.e. feedback), can I still do this if I need both inputs and outputs?
Any help would be most appreciated.
I'm working on something wich require a differential to differential amplifier. I do not want to use op amps for this, only discrete components.
I have tried to use various versions of the common long tailed pair, but the high gain causes it to behave like a comparator. Normally you loop back a portion of the output to one of the inputs (i.e. feedback), can I still do this if I need both inputs and outputs?
Any help would be most appreciated.
Yes. You can use feedback from one output to an input, as well as from the other output to the other input. Both input signals then go to each input through a resistor, to be summed at the actual input point with the feedback signal.
Seems to me you need a sim to play with. Thry downloading SWCAD III, everybody here seems to use it. It's free.
Another smart move would be to study the internal diagram of a diff-to-diff opamp datasheet like the OPA1632.
Jan Didden
Seems to me you need a sim to play with. Thry downloading SWCAD III, everybody here seems to use it. It's free.
Another smart move would be to study the internal diagram of a diff-to-diff opamp datasheet like the OPA1632.
Jan Didden
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