Two Stage Amplifier -- Find the Input Resistance

Thread starter IronaSona
Start date May 2, 2021
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Amplifier Input Resistance

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1 reply · 2K views · last reply May 2, 2021

IronaSona

Thread starter
May 2, 2021

Homework Statement: .

Relevant Equations: .

Am trying to find Effects of Feedback - Input resistance of this circuit.
Is this the formula that in need to use to find the input resistance of this circuit ?

Equations: Vi/Ii = (V'i/Ii)(1 + βA0), so Rif = Ri(1 + βA0), with Rif boxed.

Schematic of a two-stage bipolar transistor amplifier with a 5 V supply, input capacitor C1 (0.005 µF), transistors Q1 and Q3 (BC846B), resistors R1 1k, R2 950, R3 2.5k, R4 2.6k, R5 260, R6 120, capacitors C2 2µF, C3 0.01µF, C4 0.01µF, and load Rload 1Meg.

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berkeman

Admin

May 2, 2021

Where do you see feedback in this amp? And R1 and R2 are in parallel with the input impedance of Q1...

Two Stage Amplifier -- Find the Input Resistance

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