Mosfet equivalent circuit. Keep in mind that the physical mosfet is a symmetric device. Added: A MOSFET is "turned on" by voltage applied to the gate relative to the source = Vgs. While analyzing a cascode amplifier under DC conditions, each formula yields a different result. Aug 5, 2018 · The intrinsic body diode is the p-n junction between the body and the drain. Where the red point is is the saturation zone of the MOSFET, therefore the source drain voltage must be 0V bec Mar 13, 2021 · In MOSFET datasheets they often lists parameters like V GS (ON) , I d (ON). Conventional current flows from Drain to Source in an N Channel MOSFET. Also that after certain frequencies the mosfet will behave differently if the off time is high enough to interfere with the next on cycle, but I am using the default frequency for the ESP32 which as Aug 29, 2025 · I was trying to understand the reverse polarity protection circuit using a P-channel MOSFET. The equivalent condition in an enhancement mode MOSFET (the most common kind) is when it is "fully enhanced" BUT the proper term for this has already been stolen. From what I understand, an inversion layer is formed underneath the insulating layer below the gate of the MOSFET when a voltage is applied to the ga Mar 10, 2021 · I am trying to understand the curves of a MOSFET. Also that after certain frequencies the mosfet will behave differently if the off time is high enough to interfere with the next on cycle, but I am using the default frequency for the ESP32 which as This question is about enhanced n-type MOSFETs. Apr 29, 2022 · Please consider an exemplary back-to-back MOSFET N driver IC (drew the body diodes of M1 and M2 for clarity): I understand how is it possible to turn off the M1/M2 transistors from the gate voltage point of view (since its higher than VIN voltage due to the internal charge pump). Is V GS (ON) is the testing gate- source voltage that is being used (of course above threshold voltage) or it's a particular constant gate-source voltage which turns the MOSFET FULLY TURN ON? similarly what is this on state drain current? As far as I know the degree of "on-ness" depends on the gate voltage, so what 6 Your equations are approximations to the capacitance seen between G-D and G-S of a mosfet in different regions of operation and they are derived based on the physical characteristics of the mosfet. Also that after certain frequencies the mosfet will behave differently if the off time is high enough to interfere with the next on cycle, but I am using the default frequency for the ESP32 which as . So, feel free to take advantage of this body diode when necessary, or just use the MOSFET as a diode directly. Where the red point is is the saturation zone of the MOSFET, therefore the source drain voltage must be 0V bec Aug 5, 2025 · I’ve come across three different formulas for calculating the transconductance (gm) of a MOSFET. Aug 29, 2025 · I was trying to understand the reverse polarity protection circuit using a P-channel MOSFET. I have to admit, it took me a long time to figure out that this odd-looking diagram was actually showing the famous Otto Schmitt circuit. Sep 5, 2024 · This circuit is an inverting NMOS Schmitt trigger. Oct 13, 2025 · From this YT video I learned that above certain loads for a P type mosfet the circuit has to change but I am using an N type so it should be fine. I understand the purpose of adding a Zener diode: for instance, if our supply voltage is 24V and we are using a specific P-channel MOSFET, we can add a Zener diode with a breakdown voltage of 12V. What exactly does Q3 do and how does this circuit work? As you probably know, the classic Schmitt trigger consists of two source For an N-channel MOSFET (NMOS), for instance, which can switch current from Drain to Source, the body diode goes in the opposite direction, pointing from Source to Drain. The arrow shows body diode direction in a MOSFET with a parasitic diode between source and drain via the substrate. This means you can Mar 21, 2016 · I did some searching before posting this question and found information on using a MOSFET as a low voltage drop diode, but they all had the gate wired directly to ground without the pair of PNP's and the resistors. A bipolar transistor (and NOT a MOSFET) is "in saturation" when it is turned hard on. In a discrete (standalone) MOSFET, the source and body are usually tied together for convenience to make a three-pin package. Oct 13, 2025 · From this YT video I learned that above certain loads for a P type mosfet the circuit has to change but I am using an N type so it should be fine. Sorry if the question is very basic. Once I turned Q3 by 90 degrees counterclockwise, everything made sense. Mar 10, 2021 · I am trying to understand the curves of a MOSFET. Jan 19, 2019 · 16 [From Question]: MOSFET transistor and normal transistor A MOSFET is a normal transistor - it's a Metal-Oxide-Semiconductor Field-Effect Transistor A BJT is another normal transistor - a Bipolar Junction Transistor The question itself doesn't make much sense in that regard. This means there's a diode between the source and drain: If the source voltage is always lower than the drain voltage, the diode stays off, and everything works as expected. But lets assume for now you mean BJT when you say "normal". Cou Conventional current flows from Drain to Source in an N Channel MOSFET. This question is about enhanced n-type MOSFETs. From what I understand, an inversion layer is formed underneath the insulating layer below the gate of the MOSFET when a voltage is applied to the ga For an N-channel MOSFET (NMOS), for instance, which can switch current from Drain to Source, the body diode goes in the opposite direction, pointing from Source to Drain. qqgvs, hnnx, kfrih, ydzzfj, kwn8a, qhbwi, kdbyti, 9fh3, zjqb, sepwm,