更新时间2021-03-18 07:31:07
1、IBQ = ( 12 - UBE )/RB = ( 12 - 0.7 )/510k = 0.022157 ma ;
ICQ = βICQ = 80 * 0.022157 = 1.772549 ma ;
UCEQ = 12 - ICQ * RC = 12 - 1.772549 * 4.3 = 4.378 v ;
2、rBE = rbb + 26/IBQ = 200 + 26/0.022157 = 1373 Ω;
输入阻抗 ri = rBE//RB = 1373//510000 = 1370Ω;
uBE = us * ri/( ri + Rs ) = 2 * 20 * 1370/( 1370 + 3300 ) = 11.7345 mv ( 峰峰值 );
iB = uBE/rBE = 11.7345/1373 = 0.0085466 ma;
ic = βiB = 80 * 0.0085466 = 0.684 ma;
uCE = Rcic = 4300 * 0.684 = 2940 mv = 2.94 v ( 峰峰值 );
电压放大倍数 Au = uCE/us = 2940/40 = 73.5 。
3、微变等效图请按教材示例自己画 。