544 



THE BELL SYSTEM TECHNICAL JOURNAL, JULY 1951 



which tend to vary from unit to unit. This sort of stage does not produce a 

 phase reversal. 



>2 



hu) 



+ 



V, 



(16) 



Fig. 14 — The grounded base connection of a transistor. 



For the grounded base stage shown in Fig. 14, 

 Rii = re + n =" 266 ohms 

 Rn = n = 240 ohms 

 R-Li = rm-\- n = 13.1 (10)^ ohms 

 R22 -= rc-{- n^ 13.4 (10)^ ohms 



a = — 



u + n 



= 0.9785 



In this case if rt is neglected by comparison with r^ and fe , equation (8) 

 leads to 



V2 = 



uRlVq 



(re + rft + Rg){\ + Rl/tc) - art 



(17) 



Since for these transistors — {=a) is always less than unity, the output 



r« 



voltage is in phase with the input voltage. Furthermore, if Rl is very high, 



the output voltage is enormous by comparison with the input voltage. For 



•example, ii Rg = and Rl is infinite 



V2 = v. 



"re-\-n 

 and for the numerical example this is 



V2 = 4.93 (10)* Vfl. 



(18) 



