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

Configuration

Circuit without resistors R₁, R₂

Analysis

$V_{B}=V_{i}$

$V_{E}=V_{B}-0.7=V_{B}$

$I_{E}={\frac {V_{E}}{R_{4}}}={\frac {V_{B}}{R_{4}}}$

$I_{C}=I_{E}$

$V_{C}=V_{C}-I_{C}R_{3}$

$V_{C}=V_{i}(1-{\frac {R_{3}}{R_{4}}})$