Questions tagged [mosfet]

An transconductance (using voltage to control current) electronic component used for switching and amplification. Acronym for Metal-Oxide-Semiconductor Field-Effect Transistor. (from http://en.wikipedia.org/wiki/Transistor)

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50 views

Problems with low-side MOSFET in 12V LED dimming switch

I'm pretty new to electrics/electronics. I'm sorry if I make dumb questions, and thank you for your time. I wanted to control my LED strip shipped from Ebay, which works well with 12V 2A DC adapter. ...
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52 views

What happens if a voltage is applied to the gate of a MOSFET when both drain and source are shorted?

Can this damage P- or N-type MOSFETs? Does this affect gate current absorption? A side question: Instead of connecting D and S together and letting them float, what if they are both tied to ground, ...
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58 views

Current Dependent Switch [closed]

I have a 24v DC circuit; I need a contact that breaks the positive line if the current in the negative line differs from the current in the positive line. So if the negative line has become broken or ...
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50 views

MOSFET Rds on curves

I'm attempting to switch a resistive DC load (50VDC @ 10 amps) using an N-channel MOSFET. This is the particular MOSFET I'm considering. https://www.ti.com/lit/ds/symlink/csd18536kcs.pdf On page 1 ...
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58 views

Driving a MOSFET with a lower Vgs than required?

I'm working on a project where I need to control a MOSFET through an arduino uno. The MOSFET I've selected is a IRFP460, and the Vgs characteristic is Vgs = 10V. Can I run it through an arduino PWM ...
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84 views

Half-bridge circuit not working, high side running hot

As I'm a noob in this field I’m experimenting with a half bridge circuit to run a buck converter to learn about it. First I tested my circuit by putting everything together on a breadboard and it ...
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70 views

How to tune period for MOSFET IRF3205 with gate driver optocoupler PC817?

I want to test 100W power output using coils for wireless power transfer project. I used 2 IRF3205 MOSFETs with 2 gate driver optocouplers PC817. I used Arduino for optocouplers. The problem is I don'...
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39 views

Explanation of capacitor usage in this N-MOS application

I'd like to understand why capacitor is used in this circuit instead of connecting PWM pin directly to N-MOS. How does Q3 have HIGH reference with no direct connection? What kind of advantage I have ...
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32 views

Why is the gate phisically bigger than the inversion layer in a MOSFET?

In other words why does the gate overlap a bit of the source and drain instead of being exactly on the middle, please look on the following diagram You can clearly see that L is smaller than the gate ...
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33 views

Short-channel MOS body effect

Using the Cadence GPDK045, I generated the following plots of threshold voltage (left) and drain current (right) vs. body voltage for an NMOS device with 45nm channel length. As you can see, over a ...
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IRFZ44N with Arduino works fine on breadboard but not when directly connected with wire

I have a circuit that looks like this in the picture below. I am getting 5V to power Arduino Nano BLE 33 from the powerboost 500 module that is connected to the 450mAh lipo battery and the wireless ...
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84 views

Why coil at high frequency pass lower current?

I am currently working on a project that uses an H-bridge to output different direction current. I use 2 P-channel MOSFETs (IRF4905), and 2 N-channel MOSFETs (IRF3710) to build my H-bridge. *reference ...
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47 views

MOSFET N loss power battery calculation

I have a circuit to calculate my battery level using NodeMCU. I use this formula: ...
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49 views

nRF52840 with optocoupler and mosfet

I would like to make a switch which will be able to switch on/off 12-60V low current devices using nRF52840, optocoupler and mosfet. I found this schematic and my idea was just to adjust R1 because ...
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287 views

How to increase the output current of a dual supply (virtual ground) circuit

I need to build a dual 5 volts power supply capable of 200mA output current. I've seen designs using TLE2426 and BUF634, but they cost too much for my project. Is it possible to use a simple OpAmp ...
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70 views

Basic voltage/current regulation with MOSFET, cannot fully close current controlling MOSFET

I tried to decrease value of Rg resistor on the gate of the MOSFET (the one on the right) but then the MOSFET does not open enough and i get low currents trough it, i have this setup on breadboard and ...
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61 views

Transconductance value in LTSpice

I am trying to work out how to specify the transconductance value or Kn for LTspice. I have a part I can't find a suitable model for so I'll need to create one. I've tried this before and got values ...
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52 views

Can I use MOSFET as replacement for the SSR or EM relay?

I am trying to look for a solution that can help me in turning ON/OFF my 24VDC, 2A LED load. So as per the application needs I may have to turn ON/OFF this load 30 times max per day. So it is a DC ...
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58 views

Removing collected charges in a IC CMOS circuit exposed under a 30keV electron beam source

I would like to know if there is any mechanism (for example UV light exposition) to remove charges collected in an IC CMOS circuit that was exposed under a 30keV electron beam source. Presumably, ...
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46 views

Parallel MOSFET and H-Bridge

I need to control a 12V 100A DC motor and I was thinking of using this circuit, I saw many post and application notes that talk about parallelizing MOSFETs but I did not see any circuit using MOSFET ...
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71 views

basic p-type mosfet circuit, breaks mosfet?

So I've made this basic circuit to drive Vout between ~0V and ~1.65V. The default state should be ~0V, hence I use a p-type mosfet: https://docs.rs-online.com/d95a/0900766b800ae907.pdf Now, for some ...
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73 views

MCU, N-channel MOSFET, ~15m led strip, 24V power supply. Whats happening?

Disclaimer Hi, Firstly, I'd like to underline, that I do not have masters degree from electrical engineering and I didn't study electrical engineering on high school. I'm software engineer who likes ...
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48 views

Simultaneous wireless information and power transfer using MOSFETs for modulation

I have found an interesting simultaneous wireless information and power transfer concept where two MOSFETs are used as switches to switch two other resonant capacitors. Because of the switching in the ...
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49 views

Calculate the minimal MOSFET source current needed for 12 TTL MOSFETS [closed]

This is definitely a beginner question as this is the second PCB I ever designed but you can't learn unless you do something. (It's an optimization of an older board I have to do as project.) I would ...
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57 views

Error in compensator for buck

I'm trying to put my ZVS buck converter (DCM) in closed loop. I ran some simulations on MATLAB, and figured that just multiplying the transfer function of the open loop buck by 0.5 gives acceptable ...
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79 views

Boost converter MOSFET shorting

I apologize in advance if this is a more common sense question - I'm still learning some of the basics and using this project partially to just build my knowledge. I've built this circuit with an ...
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Mosfet Protection Diode Part Number 3S4L VH10

Mosfet Protection Diode Part Number 3S4L VH10 I can not find it or anything like it. It has 2 leads like a diode, but uses a Mosfet. Very low voltage drop. I am using it for reverse voltage ...
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35 views

Single pulse generator using discrete components

I've a board like this: simulate this circuit – Schematic created using CircuitLab What I want to do is to drive LEDs with OUTPUT pin. This LEDs are used like flash source, so I turn them ON ...
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60 views

Large voltage drop across source terminal

I am using an N-channel MOSFET to enable another IC. My gate voltage=1V, the drain voltage=3.3V. After rigging up the circuit, the voltage across EN_DC23 was measured with reference to ground and it ...
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87 views

Backfeeding MCU gate output bad?

I am trying to modify a work light (1S3P 18650 3,6V) that is controlled by an 8 pin PADUK type micro. An output from the micro goes through a 100 Ohm resistor straight to the MOSFET gate. It has the ...
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78 views

TVS/Bidirectional Zener for N-MOSFET Gate Protection

I am using a MOSFET to read a square wave, which usually ranges between -1 and 16 V. However, on occasion, the signal can reach values of -30 to 45 V. My current setup uses a Zener-protected STN3N45K3 ...
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36 views

Gate noise on KA3525

I am designing a 1kHz inverter in a push-pull configuration with KA3525 and IRF540N MOSFETs. Input - 12V Output - 110Vac - square wave filtered to sine wave Power - 15W at 1000Hz When I fire it up ...
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27 views

Can I use 2 H-Bridge for drive a motor?

I've a 12V 80A motor, for drive this i'll use a H-bridge with mosfet, in order to divide the current per H bridge we can drive a motor with 2 H-bridge? I'll use mosfet, we cant put mosfet in parallel
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74 views

TO-247 case maximum current

I've this TO-247 MOSFET http://www.datasheet.es/PDF/203551/2SK3271-01-pdf.html how much current will support this case? I've to control a 12V 80A DC Motor
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113 views

Getting glitches on GPIO using a MOSFET as a logic level converter

I need to connect an Event Detection pin (pin of the NXP NTAG 5 component) to a GPIO of the NXP i.XM6 processor. The problem is that the NTAG 5 pin has a logic level of 5V and the GPIO has a logic ...
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75 views

High gate pin current leakage on a p channel mosfet

I have added a P-MOSFET before my main circuit, between the v+ of the battery, and the Vcc main power line of the circuit, so that the battery stays disconnected and doesn't drain until I am ready to ...
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31 views

Deviation in the switch current in a flyback converter

This is the current waveform of the switch and the Vds of the MOSFET. Ideally, the current should fall off in a normal fashion with the switch turns off. Here, the current fall stops and becomes flat ...
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Why are standalone MOSFETs and transistors preferred over integrated load switches?

As a novice to EE concepts who's trying to apply it to Arduino projects, I was doing hours of research on how to electronically switch another higher current (or voltage) device/component/subsystem on ...
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106 views

MOSFET getting hot. Is it normal?

I am using a Diodes AL8871Q IC to power a XHP70 LED at 3.4 A. My thermal cam shows the MOSFET at 108 degees C after 60 seconds with PWM control running at 40% duty. Is this expected? MOSFET I am using ...
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Is there a typical “Active Directivity” for LDMOS components?

Active Directivity is a measure of how much an amplifier's source match potentially affects its output impedance, or its load match affects its input impedance. High active directivity is a good thing....
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81 views

Redesigning MOSFET switches

Consider the two circuits below, the first is the original: When HIBERNATE goes high, it switches the MOSFETs Q1 and Q2. However, because of the 10 kΩ bias resistors built into BJT Q3, it pulls ...
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125 views

The voltage becomes zero when the load is connected [closed]

This is my circuit. When I connect the load of 10 Ohm, the voltage goes to zero! The voltage goes to zero even if I put resistor of 10 kOhm.
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Bi-Directional Logic Level converter 1.8V-5V using MOSFET

I need to connect an Event Detection pin (pin of the NXP NTAG 5 component) to a GPIO of the NXP i.XM6 processor. The problem is that the NTAG 5 pin has a logic level of 5V and the GPIO has a logic ...
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1answer
35 views

Bi-directional High Side Load Switch Design

I want to design a high side load switch which can allow or block DC current in either direction based on a 3.3V input. Some considerations: The 3.3V rail is potentially created as a result of power ...
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25 views

Negative voltage to the drain of NMOS

In NMOS, when, Vgs = Vth Vds < (Vgs - Vth = 0) so, Vds is -ve, so initially I thought in nmos, if Vds is -ve, Id direction ...
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55 views

Polarity switching circuit

I have a variable resistor as a load that want the current to remain constant by changing the voltage, This circuit also has polarity switching (like H-bridge). Each time the circuit is turned on, ...
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67 views

Generating Asymmetric AC PWM with MOSFETs

I have a tricky project that requires -10 V low, +40 V high, duty<0.5%, 2 kHz PWM. Load: 50Ohm resistive (forward),backward is probably in MOhm range. max power 1W (only works with very low duty). ...
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56 views

Arduino transistor switch

I'm building an Arduino switch for two different signals and I'd be very grateful if you can revise the schematic and tell me if there's something wrong or if something can be improved. In the ...
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154 views

How to drive a high side MOSFET with an optocoupler correctly?

I am trying to create an absolutely minimal motor driver, to create a <5$ low power odrive. But since I am only a software developer, I do not have a 100% understanding of analog components, and ...
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46 views

reverse polarity protection using alternative configuration

it is a typical diagram of reverse voltage protection using N channel MOSFET. what one should do is to connect the anode to the source of the MOSFET. But here instead of that I have connected to the ...