The workbench.
Quick calculations for the moments between an idea and a circuit.
01 / RF POWER
dBm ↔ watts
Absolute power, referenced to one milliwatt.
P(W) = 10^((dBm − 30) / 10)Understand the conversion ↗02 / LED CURRENT
LED series resistor
Estimate the resistance and heat in a single-LED circuit.
R = (Vs − Vf) / I · P = (Vs − Vf) × I
Use the LED’s actual ratings. Choose an available resistance at or above the result to avoid exceeding the target current, and a resistor power rating above the calculated dissipation.