MOSFET
Cdg (pf)
Cgs (pf)
rdson (Ω)
Vth (V)
Circuit
Vin (V)
VDD (V)
Rg (Ω)
RL (Ω)
Period T (μs)
Power waveform
Results
td(on) = XXX.xxx ns
ts(on) = XXX.xxx ns
td(off) = XXX.xxx ns
ts(off) = XXX.xxx ns
ton = XXX.xxx ns
Esw(on) = XXX.xxx μJ
Esw(off) = XXX.xxx μJ
Eon = XXX.xxx μJ
Etot = XXX.xxx μJ
Ptot = XXX.xxx W

MOSFET switching prediction tool

This program is a tool for teaching MOSFET switching characteristics. It calculates the switching event times and energy losses for a MOSFET switch controlling a resistive load and displays the results. The program is limited to accepting a unipolar control voltage and it is assumed that Vgs has sufficient time to reach Vin over a half-cycle.


circuit diagram

Enter specifications for the MOSFET and circuit, click the Calculate button and program will determine interval timings and losses. Clicking on the Waveforms tab will show gate-source voltage and MOSFET output signals as a function of time. Key to symbols:

SymbolDescription
CdgDrain-gate capacitance
CgsGate-source capacitance
rdsonDrain-source on-state resistance
VthThreshold voltage
VinControl input voltage
VDDSupply voltage
RgGate resistor
RLLoad resistor
TSwitching period

Disclaimer

This software intended for use in teaching MOSFET swtching characteristics. No warranty regarding the accuracy of the predictions made with this program are provided.

Copyright © 2018 Martin Foster. All Rights Reserved. Permission to use, copy, modify, and distribute this software without fee and without a signed licensing agreement is strictly prohibited. Any warranties including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose are disclaimed. The software and accompanying documentation, if any, provided hereunder is provided "as is". No obligation to provide maintenance, support, updates, enhancements, or modifications is made.