DS terminates Page 10 the two terminates between Drain and SourceVGS Page 10 pulsed voltage applied on Gate (source was grounded)Vds Page 10 Voltage on Drain (source was grounded)Vdoff Page 10 Vds with a fixed voltage, and VGS with a pulsed voltage, when VGS turn off, the measured Vds reading after delay time is called Vdoff(Vturnoff), see below left pictureAC test tf