I was given the problem for homework to design the values of Rc, Rb, and Re given the following specifications:
Vcc=9V
Vce at midpoint
Ic=1 mA
βdc=300
Using the guidelines for VDB from Albert Malvinos "Electronic Principles" I came up with:
Ve=0.1*Vcc
Ve=(0.1)(9V)
Ve=0.9V
Re=Ve/Ie Since Ie≈Ic
Re=0.9V/1mA
Re=900Ω
Rc=4Re
Rc=4(900Ω)
Rc=3.6kΩ
Rb= βdc(((VccVbe)/Ie)RcRe)
Rb=300(((9V0.7V)/1mA)3.6kΩ900Ω)
Rb=1.14MΩ
But when I plugged these numbers back into the equation
Ie=(VccVbe)/Rc+Re+Rb/βdc, I got Ie=1.8mA.
Is there something that I am doing wrong? How should I go about calculating these resistor values? Also are there any specific guidelines that I should follow?
Best,
Ron
Vcc=9V
Vce at midpoint
Ic=1 mA
βdc=300
Using the guidelines for VDB from Albert Malvinos "Electronic Principles" I came up with:
Ve=0.1*Vcc
Ve=(0.1)(9V)
Ve=0.9V
Re=Ve/Ie Since Ie≈Ic
Re=0.9V/1mA
Re=900Ω
Rc=4Re
Rc=4(900Ω)
Rc=3.6kΩ
Rb= βdc(((VccVbe)/Ie)RcRe)
Rb=300(((9V0.7V)/1mA)3.6kΩ900Ω)
Rb=1.14MΩ
But when I plugged these numbers back into the equation
Ie=(VccVbe)/Rc+Re+Rb/βdc, I got Ie=1.8mA.
Is there something that I am doing wrong? How should I go about calculating these resistor values? Also are there any specific guidelines that I should follow?
Best,
Ron
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