Fairchild AN-7502 manual Application Note, Turn-On, Turn Off, Fairchild Semiconductor Corporation

Models: AN-7502

1 9

Page 8

Application Note 7502

10V

VDD

Turn-On

RO = RD

(drain-to-ground capacitance of driving device adds to CGS of driven MOSFET.)

Turn Off

RO = rDS(ON) of driving MOSFET when

RD is very much greater than RDS(ON)

Application Note 7502 Rev. A1

Image 8

Contents

Device Models Gate Drive Constant Voltage or Constant CurrentPower MOSFET Switching Waveforms A New Insight Title N75Application Note Equivalent CircuitSix States State 1 MOS Off, JFET OffA New Device Characterization Application NoteState 2 MOS ActIve, JFET ActIve State 3 MOS Active, JFET SaturatedStep-Voltage Gate Drive Application NoteExperimental Verification 1 - VGSTH/VGUsing the Characterization Curve, Figure Application NoteExperimental Verification State 1 MOS Off, JFET OffCharacterization-Curve Limits ConclusionsAppendix A - Analysis for Resistive Step Voltage Inputs Application NoteAppendix B - Estimating RO for Some Typical Gate-Drive Circuits Application NoteTurn-On State 1 MOS Off, JFET Off State 5 Mos Active, JFET SaturatedApplication Note Turn-OnTurn Off Case 3 Common-Source Gate Drive, Figure B-3ACEx CROSSVOLT