THE CATHODALLY SCREENED CATHODE FOLLOWER 



that i?^.Q< 7?inC. Calling T^ = R^^C, and T^ = R^C^, and A 

 roots are 



This is maximally oscillatory when T^ = T^, and reduces to 



\i A is large (e.g. 100) the solution is approximately 



gmRR^ 



v = E. 



1 +A 



1 - e 



cos 



<f-^l 



1+/1 



Figure 18.5 



The ringing frequency is {Ayi^jT 



The amplitude declines by g-2W(4)i'^ j^ each cycle. 



Readers who care to substitute back the original values into the expression 

 for the ringing frequency will find it is the same as that near which the 

 'resonance' occurs in the steady-state analysis. 



For triode cathode followers the figure for A would be not gm^K ^^^ 

 (/uR^)KRk + O- 



262 



