An npn BJT has gm = 38 mA/v, Cµ = 10-14 F, Cπ = 4 × 10-13 F and DC current gain β0 = 90. For this transistor fT & fβ are
A. fT = 1.64 x 108 Hz & fβ = 1.47 x 1010 Hz
B. fT = 1.47 x 1010 Hz & fβ = 1.64 x 108 Hz
C. fT = 1.33 x 1012 Hz & fβ = 1.47 x 1010 Hz
D. fT = 1.47 x 1010 Hz & fβ = 1.33 x 1012 Hz
Answer: Option B
This Question Belongs to Electronics And Communications Engineering >> Analog Electronics
Join The Discussion
Comments ( 2 )
The action of JFET in its equivalent circuit can best be represented as a
A. Current controlled Current source
B. Current controlled voltage source
C. Voltage controlled voltage source
D. Voltage controlled current source
In a p+n junction diode under reverse bias, the magnitude of electric field is maximum at
A. The edge of the depletion region on the p-side
B. The edge of the depletion region on the n-side
C. The p+n junction
D. The center of the depletion region on the n-side
To prevent a DC return between source and load, it is necessary to use
A. Resistor between source and load
B. Inductor between source and load
C. Capacitor between source and load
D. Either A or B
fT = gm / 2π(Cπ +Cπ)
fβ = fT / β0
Given values:
gm = 38 mA/V
Cµ = 10^(-14) F
Cπ = 4 × 10^(-13) F
β0 = 90
Calculating fT:
fT = (38 mA/V) / 2π(10^(-14) + 4 × 10^(-13) F)
Please sir How to solve this Question