Electronics Handbook/Circuits/NPN Transistor Configurations/Amplifier with 2 Resistors

Configuration

Circuit without resistors R₁, R₂

Analysis

$V_B=V_i$

$V_E=V_B-0.7=V_B$

$I_E=\frac{V_E}{R_4}=\frac{V_B}{R_4}$

$I_C=I_E$

$V_C=V_C-I_C{R}_3$

$V_C=V_i(1-\frac{R_3}{R_4})$