MOSFET Conduction Loss Calculator
Calculate conduction losses based on Rds(on), current, duty cycle, and junction temperature.
Input Parameters
mOhm
A
%
C
%/C
Conduction Loss
3.438 W
Rds(on) at Tj
68.8 mOhm
Voltage Drop
688 mV
Continuous Loss
6.875 W
Loss per mOhm
0.050 W
Design Notes
Rds(on) increases with temperature. At 100C, Rds(on) is 38% higher than at 25C. Consider paralleling MOSFETs to reduce conduction losses.
Conduction Loss Theory
Conduction losses occur when the MOSFET is fully on and conducting current. The loss is determined by the I^2R relationship and the duty cycle of operation. Rds(on) increases with temperature, creating a positive feedback loop that must be managed.
Pcond = Irms^2 x Rds(on) x D