This question came up in my exam and it states
Consider the diferential pair represented in the circuit.Determine VA,VCE,VC,IC for every transistor in the following conditions:
R1=R4=1K R2=13K R3=2.7K VBE=0.6V VCC=VEE=15V
a)V1=V2=0V
b)V1=V2=5V
c)V1=2V and V2=5V
I have written the following equation:
VR2+2VBE+(-20)=0,so VR2=18,6V
Then IR2=18,6/10K=1,86mA
Then VRC1=RC1*(1,86*10^-3)/2
VRC1=9,3V
For simetry reasons we have that PFR Q1=PFR Q2
VRE1=RE1*(1,86*10^-3)/2=0,465V
VRE1=0.6+0.465=1,065 V
VCEQ3=-1.065+20=18,935 V
ICQ3=1,85*10^-3 A
I did this analysis considering V1,V2 generic reference voltages.I am not seing how having different values of V1 and V2 affects the values of VA,VCE,VC,IC of the transistors.
Thanks
Consider the diferential pair represented in the circuit.Determine VA,VCE,VC,IC for every transistor in the following conditions:
R1=R4=1K R2=13K R3=2.7K VBE=0.6V VCC=VEE=15V
a)V1=V2=0V
b)V1=V2=5V
c)V1=2V and V2=5V
I have written the following equation:
VR2+2VBE+(-20)=0,so VR2=18,6V
Then IR2=18,6/10K=1,86mA
Then VRC1=RC1*(1,86*10^-3)/2
VRC1=9,3V
For simetry reasons we have that PFR Q1=PFR Q2
VRE1=RE1*(1,86*10^-3)/2=0,465V
VRE1=0.6+0.465=1,065 V
VCEQ3=-1.065+20=18,935 V
ICQ3=1,85*10^-3 A
I did this analysis considering V1,V2 generic reference voltages.I am not seing how having different values of V1 and V2 affects the values of VA,VCE,VC,IC of the transistors.
Thanks
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