View irf640s datasheet:

PD -90902B IRF640S/L HEXFET® Power MOSFET Surface Mount (IRF640S) D Low-profile through-hole (IRF640L) VDSS = 200V Available in Tape & Reel (IRF640S) Dynamic dv/dt Rating RDS(on) = 0.18? 150°C Operating Temperature G Fast Switching ID = 18A Fully Avalanche Rated S Description Third Generation HEXFETs from International Rectifier provide the designer with the best combinations of fast switching , ruggedized device design, low on-resistance and cost- effectiveness. The D2Pak is a surface mount power package capable of accommodating die sizes up to HEX-4. It provides the highest power capability and the lowest possible on-resistance in any D 2 Pak TO-262 existing surface mount package. The D2Pak is suitable for high current applications because of its low