Common Emitter Amplifier Calculator (Small Signal Analysis)

This calculator computes the Diffusion Resistance (rp), Transconductance (gm) and Output Voltage gain (AV) for a common emitter (CE) BJT amplifier. In the common emitter mode the base terminal of the transistor is the input, the collector is the output and the emitter is common to both the base and collector. Common emitter amplifiers provide an inverted output with a high gain. The gain of this configuration is a function of temperature and the bias current.

*For self-biasing, V_BB=V_IN.(R₂/R₁+R₂) and R_B=(R₁.R₂)/(R₁+R₂)

** Enter T=300 K if nothing else is given.

Small signal circuit analysis of a Common Emitter (CE) BJT Amplifier

Temperature (T)

Common Emitter Current Gain (β)

Base current (I_B)

Calculate base current here

Base Resistance (R_B)

K-Ohm

Collector Resistance (R_C)

K-Ohm

Result

Diffusion Resistance (rπ)

K-Ohm

Transconductance (g_m)

mA/V

Output Voltage gain (A_V)

V/V

Click here to view image

where

rπ=diffusion resistance

g_m=trans conductance