Tabela de fórmulas BJT

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TABLE 4.1 
 BJT Bias Configurations 
 Type Configuration Pertinent Equations 
 Fixed-bias 
 IB =
VCC - VBE
RB
 
 IC = bIB, IE = (b + 1)IB 
 VCE = VCC - IC RC 
 Emitter-bias 
 IB =
VCC - VBE
RB + (b + 1)RE
 
 IC = bIB, IE = (b + 1)IB 
 Ri = (b + 1)RE 
 VCE = VCC - IC (RC + RE) 
 Voltage-divider 
bias 
 EXACT: RTh = R1||R2, ETh = R2VCCR1 + R2 
 IB =
ETh - VBE
RTh + (b + 1)RE
 
 IC = bIB, IE = (b + 1)IB 
 VCE = VCC - IC (RC + RE) 
 APPROXIMATE: bRE Ú 10R2 
 VB =
R2VCC
R1 + R2
, VE = VB - VBE 
 IE =
VE
RE
, IB =
IE
b + 1
 
 VCE = VCC - IC (RC + RE) 
 Collector-feedback 
 IB =
VCC - VBE
RF + b(RC + RE)
 
 IC = bIB, IE = (b + 1)IB 
 VCE = VCC - IC (RC + RE) 
 Emitter-follower 
 IB =
VEE - VBE
RB + (b + 1)RE
 
 IC = bIB, IE = (b + 1)IB 
 VCE = VEE - IE RE 
 Common-base 
 IE =
VEE - VBE
RE
 
 IB =
IE
b + 1
, IC = bIB 
 VCE = VEE + VCC - IE (RC + RE) 
 VCB = VCC - ICRC 
VCC
RCRB
�
 
VCC
RC
RE
RB
�
 
RCR1
RE
R2
�
VCC
 
RC
RF
RE
�
VCC
 
RB
RE
–VEE 
RE
VEE
RC
VCC
–
+
+
–
 
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