+ Ω Typical MOSFET voltage ratings Portable equipment 20V FPGA, VLSI supply 20V,30V 24V motor drive 48V system 80V system 60V 80-100V 150-200V 85VAC – 220VAC Three phase PSU 450-600V 800-1000V Ω Ω Ω Ω Ω Ω Ω Ω 1x 0.65x 1x 0.65x Rth junction-case Rth case-ambient Rth + Cth junction-case Rth + Cth case-ambient Ω Ω = × = × × = − = × − Ω Ω ⎛ =⎜ ⎝ × ⎞ ⎟( ⎠ ⎛ ) ⎜⎜ ⎝ + + + ⎞ ⎟ ⎟ ⎠ Ω Ω The negative voltage scale has been exaggerated Ω = = × × × ⎛ = ⎜⎜ − ⎝ ×10−3 ⎛ × ⎜⎜ ⎝ ⎞ ⎟⎟ ×10 −9 ⎠ ≈ × ⎞ ⎟⎟ × ⎠ × ⎛ × ⎜⎜ ⎝ × ⎞ ⎟⎟ × ⎠ − −