Two Stage Amplifier input resistance

Thread Starter

ironasona

Joined Nov 12, 2020
53
Hi i got a question ,how do i calculate the input resistance ,of the RS resistor ,so i would get half of the voltage of the voltage source (500mA) .I've created the circuit in ltspice and found out that its around 95K ohms ,but how would i calculate it .

Any help would be great

Ive attached my calculations and the simulation image
 

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Thread Starter

ironasona

Joined Nov 12, 2020
53
Hi i got a question ,how do i calculate the input resistance ,of the RS resistor ,so i would get half of the voltage of the voltage source (500mA) .I've created the circuit in ltspice and found out that its around 95K ohms ,but how would i calculate it .

Any help would be great

Ive attached my calculations and the simulation image
ye 500mV and am trying to get 250mVolts on the output of the RS
 

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ericgibbs

Joined Jan 29, 2010
13,580
hi iron
I guess you know that the signal level will a function of the input frequency.

This is one way in LTS that can show the RSv

E
To show the mVolts, RIGHT click on the left side plot Y axis, select Linear


Update:
Added 2nd plot image...

BTW: Your 500mV source is actually 1Volt peak to peak
 

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