MOSFET Power Calculator
Calculate MOSFET conduction losses from on-resistance and drain current plus switching losses.
mΩ
A
kHz
ns
V
Conduction Loss
1.250 W
Switching Loss0.150 W
Total Power Loss1.400 W
Conduction Loss vs On-Resistance (Rds_on)
MOSFET Power Losses
Conduction Loss
P_cond = Rds(on) x I_D^2
Switching Loss
P_sw = 0.5 x V_DS x I_D x (t_rise + t_fall) x f_sw
Total loss is the sum. Conduction loss dominates at low frequencies; switching loss dominates at high frequencies.
Example Calculation
MOSFET with 50 mohm Rds(on), 5 A load, switching 12 V at 100 kHz with 50 ns transitions.
- 01Conduction = 0.05 x 25 = 1.25 W
- 02Switching = 0.5 x 12 x 5 x 50e-9 x 100000 = 0.15 W
- 03Total = 1.25 + 0.15 = 1.40 W
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