LvW
Advanced Member level 6
`phase shift compensation
Hi desperado,
it is not easy to answer you as I don´t know at which point you have problems to understand.
Let me repeat: neg. feedback means that within a certain frequency range the incoming signal is combined with another signal (from the output) which is 180 deg. out of phase.
For this scenario you have two basic alternatives:
1.) feedback to the inv. terminal (gives neg. feedback for frequencies without parasitic resp. additional phase shifts)
2.) feedback through an additional inverter to the non-inv. terminal (for the same restrictions as above)
However, case 1) ans 2) turn into pos. feedback for higher frequencies when additional phase shifts occur reaching 180 deg. But, if the loop gain magnitude is low enough at this point, there will be no stability problems.
Hi desperado,
it is not easy to answer you as I don´t know at which point you have problems to understand.
Let me repeat: neg. feedback means that within a certain frequency range the incoming signal is combined with another signal (from the output) which is 180 deg. out of phase.
For this scenario you have two basic alternatives:
1.) feedback to the inv. terminal (gives neg. feedback for frequencies without parasitic resp. additional phase shifts)
2.) feedback through an additional inverter to the non-inv. terminal (for the same restrictions as above)
However, case 1) ans 2) turn into pos. feedback for higher frequencies when additional phase shifts occur reaching 180 deg. But, if the loop gain magnitude is low enough at this point, there will be no stability problems.