#### Electronman

##### New Member

HI,

I am involving to a question these days,

I just want to know how to calculate the input impedance for an common emitter BJT configuration? Do we have a such phrase (ie input impedance for a bjt) or input impedance is equal to the input resistance which is calculated by small signal models like pi model?

suppose I want to calculate the input impedance of my BJT to see if my Mic is suitable to be used by my common emitter configuration, then what do I need to do? Do I need to calculate the input impedance (resistance?) of the BJT configuration or just knowing the high or low impedance of my configuration and the MIC is enough thing to be known?

Thank.

I am involving to a question these days,

I just want to know how to calculate the input impedance for an common emitter BJT configuration? Do we have a such phrase (ie input impedance for a bjt) or input impedance is equal to the input resistance which is calculated by small signal models like pi model?

suppose I want to calculate the input impedance of my BJT to see if my Mic is suitable to be used by my common emitter configuration, then what do I need to do? Do I need to calculate the input impedance (resistance?) of the BJT configuration or just knowing the high or low impedance of my configuration and the MIC is enough thing to be known?

Thank.

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