4th Generation EF Series MOSFETs Vishay / Siliconix 4th Generation EF Series MOSFETs offer an extremely low figure-of-merit (FOM) rating for high-performance switching and high efficiency. The MOSFET FOM is calculated as ON-resistance (R(DS)ON) multiplied by gate charge (Qg). Built on Vishay 4th generation super-junction technology, these MOSFETs feature a low typical ON-resistance range of 0.088Ω to 0.225Ω at VGS=10V and a gate charge down to 21nC. For improved switching performance, these devices provide low effective output capacitances (Co(er) and Co(tr)). These values translate into reduced conduction and switching losses to save energy. Vishay / Siliconix 4th Generation EF Series MOSFETs are offered in PowerPAK® 8x8 and TO-220AB packages. The series is designed to withstand overvoltage transients in avalanche mode with guaranteed limits through 100% UIS testing.