Message	Date	From	Subject
4656	2010-05-06 11:30:41	kanewderfish	2 stage buffer amp from SSDRA
Hi gang, Somewhere early on in "Solid State Design for the Radio Amateur" (I don't have my copy in front of me), there is a schematic for a 2 stage BJT buffer amplifier. It is the one where the second stage is an DC coupled emitter follower, and it's emitter resistor is connected via a voltage divider back to the base of the first stage. With the values given it is pretty easy to leap-frog through the circuit and come up with the DC and AC values that characterize the circuit, but I'd like to know more about the >selection< of these values. Can anyone point me to where I can find more information about designing this circuit for different values of Zin, gain, stability, bias current, etc.? Anything from 'rules of thumb' to a more rigorous analysis would be appreciated. Thanks!
4658	2010-05-06 12:19:27	Tim	Re: 2 stage buffer amp from SSDRA

Hi gang,
Somewhere early on in "Solid State Design for the Radio Amateur" (I don't have my copy in front of me), there is a schematic for
a 2 stage BJT buffer amplifier. It is the one where the second stage
is an DC coupled emitter follower, and it's emitter resistor is connected via a voltage divider back to the base of the first stage.

With the values given it is pretty easy to leap-frog through the circuit and come up with the DC and AC values that characterize the circuit, but I'd like to know more about the >selection< of these values. Can anyone point me to where I can find more information about designing this circuit for different values of Zin, gain, stability, bias current, etc.? Anything from 'rules of thumb' to a more rigorous analysis would be appreciated.

Thanks!