IRF6665PbF Current Regulator Id Same Type as D.U.T. Vds 50KΩ Vgs .2µF 12V .3µF +V D.U.T. DS - VGS Vgs(th) 3mA I I G D Current Sampling Resistors Qgs1 Qgs2 Qgd Qgodr Fig 17a. Gate Charge Test Circuit Fig 17b. Gate Charge Waveform D.U.T + Circuit Layout Considerations • Low Stray Inductance • Ground Plane • Low Leakage Inductance - Current Transformer + - + - R VDD G • di/dt controlled by RG • Driver same type as D.U.T. + • ISD controlled by Duty Factor "D" • D.U.T. - Device Under Test - Driver Gate Drive P.W. Period D = P.W. Period V * GS=10V D.U.T. ISD Waveform Reverse Recovery Body Diode Forward Current Current di/dt D.U.T. VDS Waveform Diode Recovery dv/dt VDD Re-Applied Voltage Body Diode Forward Drop Inductor Curent Inductor Current Ripple ≤ 5% ISD * VGS = 5V for Logic Level Devices Fig 18. Diode Reverse Recovery Test Circuit for N-Channel HEXFET® Power MOSFETs 6 www.irf.com
