纵电子做味 第3章放大电路基础 例3.33(1)求静态工作点;(2)求电路的差模Aa,Rn,Rn R r+rcc [解](1)求“Q 75k古 C+6V EE U BEA 6-0.7 7.5kQ REF ri+R 6.2+0.1 1009 L 22 REF ≈0.84(m4) B=100 0=1 REF 0.84mA 6.2k R3 10032100c CQ1CQ2 0.5I0=0.42mA 6 VE U CO1 CO2 6-0.42×75=285(V) 26 (2)Aud, Rid, Ro rhe=Ihe?=200+101 6452(9) 0.42 BRc 100×75 d -65 r+(1+f)B645+101×0.05 Ra=2be+(1+f)是Rpl=23k2R。=2R=15(k2)例 3.3.3  = 100 (1)求静态工作点；(2)求电路的差模 Aud，Rid，Ro。 [解] (1) 求“Q” 1 2 EE BE4 REF R R V U I + − = 6.2 0.1 6 0.7 + − = 3 2 0 REF R R I = I = 0.84 mA ICQ1 = ICQ2 = 0.5 I0 = 0.42mA UCQ1 = UCQ2 = 6 – 0.42  7.5 = 2.85 (V) (2)求 Aud，Rid，Ro 6 452 ( ) 0.42 26 rbe1 = rbe2 = 200+101 =  2 p 1 be C d r (1 ) R R Au   + + = − 65 6.45 101 0.05 100 7.5 = − +  −  = 2[ (1 ) ] 2 p 1 Rid = rb e + +  R = 23k Ro = 2RC = 15 (k)  0.84 (mA) ui1V1 +VCC V2 RC uo ui2 RC VE E R R2 3 IC3 V3 V4 IREF +6 V −6 V 100  100  7.5 k 7.5 k 6.2 k 100  第 3 章 放大电路基础