Op-Amp Log Amplifier Calculator

Calculate the output voltage using: $$ V_{\text{out}} = -V_T \ln\left(\frac{V_{\text{in}}}{R\, I_s}\right) $$

* Ensure all inputs are in SI units: $V_{\text{in}}$ in Volts, $R$ in Ω, $I_s$ in Amperes, and $V_T$ in Volts.

Step 1: Enter Parameters

Input Voltage, $V_{\text{in}}$ (V):

e.g., 1 V

Resistor, $R$ (Ω):

e.g., 100 kΩ

Diode Saturation Current, $I_s$ (A):

e.g., 1×10⁻¹² A

Thermal Voltage, $V_T$ (V):

e.g., 0.025 V at room temperature

Calculated Output Voltage