计算器大全
适配初、高中学生 数理学习好帮手

差动放大器计算器

R1 (KΩ) 
R2 (KΩ)
R C (Collector resistor)集电极电阻 (KΩ) 
R E (Emitter resistor)发射极电阻 (KΩ) 
VP(Supply Voltage)电源电压 (V)
Beta (DC Current Gain)直流电流增益
V BE (Base to emitter drop)基极-发射极压降 (V)
R s (Source Resistance): 电源内阻 (Ω)
R L (Load resistor)负载电阻 (Ω) 
f T (Current Gain BW Product):电流增益带宽 (MHz)
C CB (Cu Collector-Base Cap.): 集电极与基极间电容 (pF)
C BE (C π , Base-Emitter Cap.):基极和发射极之间的电容(可选) (pF)

V C (Collector Voltage)集电极电压 (V) 
V E (Emitter Voltage)发射极电压 (V) 
V B (Base Voltage)基极电压 (V) 
I E (Emitter Voltage)发射极电压 (mA) 
I C (Collector Voltage)集电极电压 (mA) 
I B (Base Voltage)基极电压 (mA) 
g m (Transconductance)跨导
r π (Input Resistance of BJT at low freq)晶体管输入阻抗,低频率的 (Ω)
r e   (Ω)
R IN (Input Resistance of Amp)放大器输入阻抗 (KΩ)
A (Amplifier Voltage Gain)放大器的电压增益
f P1 (MHz)
f P2 (MHz)

V B =  VP*R2/(R1+R2)

V E = V B -V BE

I E= V E /R E

Alpha= Beta/(Beta+1);

I C= Alpha*I E

V C = VP -  I C *R C /2

I B =I C /Beta

g m = Ic/25mA

r e = Alpha/g m

r π = Beta/g m

A= Alpha* r π * R C /( R s +2*r π )/r e

f P1 =1/( 2*π*( R s ||2*r π )*( C BE/2 + C BC ))

f P2 =1/( 2*π* R C *C BC )

f T = g m /(2π*(C BE +C BC ))

The lower pole is dominate: 

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