Mosfet Definition and 215 Threads

Homework Statement Homework Equations Id=K*(Vsg-Vth)2 KVL The Attempt at a Solution On part A, Haven't had much experience with PMOS. Used large signal model, to find Rs. Equivalent circuit: We know that Vs=0. That means Vd=-7.5 V. If we say the voltage across Rs is Vdd-Vd, then that...

Homework Statement [/B] Homework Equations K=0.5μnCox(W/L) ID=K×(Vgs-Vt)2 Kirchhoff's voltage Law The Attempt at a Solution For part A, My initial assumption was that since we are trying to find the DC bias current(to help find K), we would use the large signal, where capacitors are...

Ok, so i have a picaxe microcontroller putting out a pwm signal to the gate of an irlb3034 "logic level" n-channel mosfet. The mosfet is for grounding on and off about 8v of 20 to 40 amps. When i take my circuit and jump 8v directly to the gate of my mosfet everything works perfectly...

I am using trying to familiarize myself with P-Channel mosfets since I don't have too much experience with them. I am trying to use the FET as a switch, being driven in the typical highside FET manner using an NPN transistor. Is there some standard way of quickly discharging the FET during turn...

Preface: I'm a chemical engineering undergraduate student but as small-time and noob electrical engineering hobbyist. I really only have minimal experience in circuitry and the like. I want to build a series of electromagnets with a variable their strength in order to levitate an opposing...

I'm working on a few little 12VDC projects, and am wondering on the logic for choosing different types of transistors... Bipolar vs IGBT vs Mosfet... What makes one of them a clear choice in each application? I can see bipolar transistors would be ideally suited for for analog/linear...

Homework Statement Homework EquationsThe Attempt at a Solution We have been given this question along with some parameters. It asks for find drain votltage, my question is why isn't the drain voltage just equal to 1.8? I mean the resistor should be getting the entire 1.8V so?

Homework Statement I have been given the world's longest transistor problem as an assignment :wink: Here is the circuit: I am asked to find: a) V1, V2 and V3 using DC analysis b) AC equivalent circuit c) AC tension gain: Ava=Vx/Vsig d) AC tension gain: Avb=Vo/Vx e) Total AC tension gain...

Homework Statement I would like to plot Vout vs Vin for the following circuit: Homework Equations Square law equations for MOSFET transistors. The Attempt at a Solution I'm calling the threshold voltage Vth. My understanding of the circuit is this: 1. From 0 < Vin < Vth, the transistor...

Ok, so I've read around and have become quite confused with, not only the terminology about whether a device is in linear or saturation or ohmic or active region, but now my whole concept of mosfets is on the brink of breaking down! This is my understanding. In the attached picture, the...

I'm building a MOSFET driver like this. The signal source is 7V peak-to-peak. Vcc is 12V. The push-pull stage is 2n3904/2n3906.(datasheet http://www.kynix.com/uploadfiles/pdf8798/2N3904.pdf) I've tested the push-pull output before adding the transformer, and using a 50 ohm load, the output...

Homework Statement The equations provided require the oxide permittivity (εox)as well as the oxide thickness (tox) to determine the gate oxide capacitance per unit squared (Cox). How to solve this? Homework Equations In triode region: ID = μn * Cox * W/L * ((VGS-Vth)* VDS - VDS2/2 In...

I'm looking at making a reasonably simple FET driver with current limiting / short circuit protection.. I tried to keep all the pointers in mind from my 'voltage divider with offset' thread from a month or so ago. Goals for this are to have a driver that can run off automotive power sources (I...

Let's say I have a Mosfet with Vth=4V. According to the circumstances for it to be in linear mode Vds<Vgs-Vth, if I apply Vgs of 10volts, my Vds must be lower than 6V in order for the transistor to operate just under saturation. Is that right? And if I want to use it as a switch, I would apply...

Homework Statement I've found the gain, but now I need to estimate the upper cutoff frequency with the open circuit time constant method, so the upper 3dB cutoff would roughly be $$\sum_{i = 1}^{n} \frac{1}{\tau_i}$$ The attempt at a solution I'm currently trying to make sense of the given...

Homework Statement A bypass capacitor increases gain in the mid-band region. Explain how with the figure and small signal model. Assume gm=0.5mS. Homework Equations Rs = 1 k Ohm The Attempt at a Solution With the bypass capacitor, the source would be treated as grounded and the equations...

Homework Statement I am not sure i know what is meant by the input load line and the output load line in parts b and c. I tried looking it up in my book (fundamentals of microelectronics by razavi) but to no avail. Any help is appreciated.

Hi, In my electronics class we are learning BJT, Mosfet, JFET theory. My gripe at the moment is that when teaching this you are taught how to troubleshoot and solve for circuits already made. This means you are always solving for various voltages, currents, Gm etc etc. With no previous...

Hello to all ! In MOSFET at strong inversion electrons confined to triangular quantum well, electrons occupy only 1 or 2 lowest subbands. and the Van Dort model gives the quantum mechanical intrinsic carrier density in inversion channel via increased energy band-gap(ΔE). NQM = NCL× Exp(-ΔE/2kt)...

Hi there, I m a beginner in Analog IC design field. Currently, I have a project which is to design a high sensitivity rectifier by using Synopsys simulator. However, I m stuck in the beginning part which is the DC biasing of MOSFET transistor. The design specification as below: Technology ...

Hi, my Voltage Multiplier Simulation does not work properly the first transformer is working just fine, the second one does not really seems to work, for the second transformer i tried to creat AC current with a mosfet, but i think I am doing it wrong :/, can you give me some tips how to...

Hi , I would like to find out does a mosfet have any gate charge if there is no voltage applied across D-S or no ? my intuition tells me that there shouldn't be any gate chrge as there is no voltage on the " second plate" to attract that charge like would be the case in a capacitor, although...

I am new to using MOSFET transistors as load switches. Here, I am trying to trigger the P-channel MOSFET to run a current through the 180 ohm resistor. I can not figure out what I am doing wrong. It is supposed to turn on for a small moment (at the zero-crossing moment of the AC phase), then...

Homework Statement Homework Equations How current flows through n channel mosfet since bassicaly by applying positive voltage to the drain and negative to the substrate we actualy make the depletion layer grow widher. I mean when there is positive voltage at the gate it attracts electrons and...

I'm working on a project where i need to control an electromagnet but I'm not sure how to do it. I tried using a npn but the current passing through the magnet is just to small, should I use a mosfet instead. The specifications for my project say that they will provide us with 9 volts and a...

Firstly, I'm only a beginner at electronics and most of my knowledge comes from googling things. I have (several) ultrasonic transducers (100 watt 40 khz) i'd like to drive with my ultrasonic generator (100 watts 40 khz) but I'd like to up the amplitude of my transducers because I want the...

I have an old mosfet amplifier which I plan to upgrade, I have never done this before but I am very experienced in electronics and have built many amplifiers before, just not mosfet amps. I am not 100% sure how the n and p channel mosfets are biased or set up but one upgrade I want to do with...

This is not a homework question,so please don't yell at me.. There is a question on my textbook..Analyze in a detailed manner the effects of the mismatch in the differential amplifier MOS.Which one has a dominating effect according to you and why? I know how to analyze the effects of the...

Hello, Can someone please describe in a few words the idea behind the VRG Mosfet? Focusing on the Pros and Cons of the device. Thanks!

Hello I'm starting to design my amplifier with Mesfet.I calculated my stable amplifier with scattering parameters,however I don't know how do dc bias because I don't have any dc equations for Mesfet and and I can't extract dc information from datasheet (because datasheets only define IDSS...

I don't know if this is the right way of describing it, but I need to activate an area of capacitance on a touchscreen by applying some current to a piece of conducting material like tinfoil. I am needing to remotely turn pages on a touchscreen ereading device with a microcontroller, and this...

Homework Statement Questions ask me to find the value of VG and R2 as well as Vs Homework Equations R = V/I Id = Kn(Vgs - Vth)^2 The Attempt at a Solution Before i find VG and R2 , I would like to find Vs first. Vs = R*I where R= 1k ohm and I = 1mA ? hence , Vs = 1V Is it correct for Vs?

Hi, I'm planning on using a mosfet with my raspberry pi to controll a circuit, using the GPIO pins which can be set to +3.3V or GND but I'm having problems with choosing the type of MOSFET I will need. I've found the data sheet for a possibility here http://www.diodes.com/datasheets/ZVP3306A.pdf...

https://en.wikipedia.org/wiki/MOSFETLikewise, the "oxide" in the name can be a misnomer, as different dielectric materials are used with the aim of obtaining strong channels with smaller applied voltages. http://www.electronics-tutorials.ws/transistor/tran_7.html In the saturation or linear...

Hiya, I've been mucking around with a 2n7000 MOSFET and I can successfully turn it on and off, but to turn it off I either have to put the gate at 0v and wait a few seconds and it turns off itself or apply negative voltage to the gate and it'll stay off when I return it to 0v. Is this normal for...

I would like to know why the threshold voltage increases for an NMOS transistor when the voltage difference between the source and the body terminals is greater than 0. If, for example, the body terminal is connected to -1V and the source to 0V, holes from the p-substrate are attracted to this...

Recently, I was trying to control the strength of an electromagnet with PWM over a MOSFET or IGBT with an Arduino/microcontroller. It worked but I burnt multiple MOSFETs/IGBTs while testing it, after certain time... so something must have gone wrong... I'd like to build a simple circuit, to...

In a lot of the literature out there, they make reference to the totem pole topology for driving Mosfets (as in an H-bridge) as shown in the figure attached. I for the life of me cannot understand how this is a good circuit. When the output from the PWM controller is high, the upper transistor...

I'm trying to solve for the minimum vIN such that MOSFET is in the saturation region. Here are the given parameters VS+ = 1.0 V VS- = - 1.0 V VT = 0.5 V In order to enter saturation I know that VDS > VGS - VT VGS = VIN - VS- VDS = Vs+ - Vs-, which is 2 V Which means 2V > VIN - VS- - VT 2V...

In Sedra&Smith's microelectronic circuits they have the following expression for the drain current in a MOSFET in saturation iD = 1/2µpCox(W/L)Vov2(1+VDS/VA)But I don't see how this can be correct. Wikipedia also has another expression, see...

Hey guys, I'm looking for some general-purpose N-channel JFET and/or MOSFET transistors (depletion-zone) to be used as audio frequency and radio frequency amplifiers (although probably not higher than 50 MHz). They likely won't be subject to voltages over 12 volts or current higher than 200...

Hi! Here is my task: For differential amplifier on scheme calculate voltage gains Av1=vout1/(vin1-vin2) and Av2=vout2/(vin1-vin2). MOSFET's M1 and M2 have same characteristics. MOFSTE's M3 and M4 have same characteristics. All MOSFET's are in saturation. Assume that gm*rds>>1. How to use fact...

Hi! My task is to calculate input resistance for circuit below: VDD=10V, Vtn=1V, β=1mA/V^2, VA=100V, load resistance RL=20k. Here is model for AC analysis (DC source and infinite capacitances are short circuits, current directions chosen arbitrarily): After calculationg input current iin...

Here is my circuit: Q1 is NMOS and Q2 is PMOS. Q1: VT1=0.7V, beta1=2mA/V^2 Q2: VT2=-0.9V, beta2=1.8mA/V^2. I assumed that both transistors work in saturation. In this mode it must be: Q1: VG1S1 > VT1, VG1D1 < VT1, ID1=beta1*(VG1S1-VT1)^2/2, Q2: VS2G2 > -VT2, VD2G2 < -VT2...

Long story short, I have a circuit board with I programmed smart charger on it. The microcontroller is supposed to put out 5v to trigger an enhancement type n-channel mosfet which simply connects 15v to my battery. But only 3v is coming out of the mosfet. It is an irl510, what is going on?

Greetings. I am not sure how to approximate a MOSFET's switching energy from datasheet parameters. I have stumbled upon a few ways, but in all cases I've found it is pretty rare to find a datasheet with all the correct parameters. Here are some ways I've found: 1) Eon and Eoff are listed...

Hi, I recently conducted a lab experiment involving several mosfets of varying channel length and width and have plotted Ids against Vds for different values of Vgs (below is one of the graphs). I am now trying to find the threshold voltage of each mosfet using their graphs although I am...

Can someone explain this sentence in MOSFET design.. The Since the drain will be at a positive voltage relative to the source the two pn junctions can be effectively cut off simply connecting the substrate terminal to source terminal.

Homework Statement A CS amplifier utilizes a MOSFET with μnCox = 400 μA/V2, W/L = 10, and VA=10v. It is biased at ID=0.2mA and uses RD=6k. Find Rin,AVO,RO Homework Equations VAO= -gm(RD||ro) Ro=RD||r0 The Attempt at a Solution I drew out the equivalent circuit with...

Homework Statement The diagram: http://images.fr1ckfr4ck.fastmail.fm/probC.jpg This MOSFET has the following parameters: |VT| = 0.6V μpCox = 100 (μa/V2) L = 0.25μm λ = 0 Establish a drain current of 0.8 mA and a voltage VD of 1.5V. Determine the transistor width W, and the...