SM8 Thermal Resistance and Derating Information 56 D=1(D.C.) t1 50 40 30 20 D=t1 tp tp D=0.5 D=0.2 D=0.1 D=0.05 10 Single Pulse 0 100µs 1ms 10ms 100ms 1s 10s 100s Pulse Width (s) j-a=55.6˚ C/W maximum Mounted on an FR4 p.c.b. of 50mm x 50mm connected using 25mm x 0.5mm copper wire PD - Power Dissipation (W) 2.25W and 2.75W Derating 4.0 3.0 2.75W 2.0 2.25W 1.0 0 0 20 40 60 80 100 120 140 160 TA - Ambient Temperature (˚C) Both die on 2.75W Devices Thermal Resistance (˚C/W) Thermal Resistance (˚C/W) Single die on 2.25W Devices Single device on 46 Both devices on D=1(D.C.) 40 t1 D=t1 tp tp 30 D=0.5 20 D=0.2 D=0.1 D=0.05 10 Single Pulse 0 100µs 1ms 10ms 100ms 1s 10s 100s Pulse Width (s) j-a=45.6˚ C/W maximum Mounted on an FR4 p.c.b. of 50mm x 50mm connected using 25mm x 0.5mm copper wire