Questions tagged [mosfet]
Metal-Oxide-Semiconductor Field-Effect Transistor, a type of field-effect transistor (FET). MOSFETs have an insulated gate, the voltage of which determines the conductivity of the device. This can be used for amplifying or switching electronic signals. (From: Wikipedia)
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MIL-STD-1275E surge protection
I am building a protection circuit for MIL-STD-1275E,
and my manager says the circuit will not work and to figure it out.
now I have addressed all the 4 main events in said STD: the surge, the spikes, ...
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Gate driver power supply design simplification
Looking at many reference 3 phase inverter designs given by reputed manufacturers(such as TI, Infineon, Toshiba etc), they design every aspect of the gate driver power supply. (Using pulse ...
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Can't identify logo for a 135N68A MOSFET. Hunting for datasheet. Any ideas?
This MOSFET was inside an unbranded Chinese made PWM solar charge controller with no model number:
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Is a flyback diode needed when using an RC snubber?
In order to minimize ringing when switching the mosfet, I had to implement an RC snubber circuit. Now, in that case, is the flyback diode still required?
Also, I measured with an oscilloscope the ...
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IRF9540N P-MOSFET Heating UP
simulate this circuit – Schematic created using CircuitLab
Hello, so I am trying to make a solenoid based injector driver circuit capable of ramping current from 0 to 17A within 100us and then ...
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\$I_{on}\$ and \$I_{off}\$ of MOSFET
I have a question from test ( translation from my language to English ):
We want to create MOSFET with \$\frac{I_{on}}{I_{off}}=10^4\$.
We also know that \$s=80m[V/dec]\$, what is the minimum ...
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micro usb is not giving 5v but instead vbus is giving 0.45v
I just got my first 4 layer newly assembled board from PCBway.
When USB cable is connected, the board is not powering on.
When I checked the vbus it's showing 0.45v. After this I checked the MOSFET q1 ...
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Is this schematic ready to be made into a circuit?
I made this schematic for a board that will be the brain of a lamp I want to build.
The lamp will be able to move in 2D (up-down, front-back) with two motors which are connected via J3.
The lamp has ...
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BLDC Gate Drive cross conduction
I am making a BLDC controler using 6 MOSFETs and 3 gate-drivers.
I have the following issue:
When the Low-Side MOSFET gate is active the High-Side gate is also active. It's not a problem from the gate ...
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What is the purpose of R1, D1 in this gate driver? How they can control the turn on/off time?
I'm reading the datasheet for the ZXGD3004E6 gate driver. I don't understand why R1 and D1 are there.
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Voltage spike comparison between SiC MOSFET and Si MOSFET? Which one is the lowest? [closed]
Under identical conditions (same circuit, switching frequency, PCB layout, etc.), is there a difference in the voltage spikes during turn-off between SiC MOSFETs and Si MOSFETs? Generally speaking, ...
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Solenoid driver circuit with peak hold
Many fine solutions for making a “peak hold” Solenoid driver, like TI DRV104/DRV120/TPS1H000 (1-channel), Maxim/Analog devices MAX22200 (8-channel).
But they are sole source, so the price will surely ...
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MOSFET Common-Source Stage with Resistive Load
If the Vgs is constant, the graph,
drain current is as shown If Vgs varies, the drain current is as shown
My question is, what actually is a saturion region for MOSFET? Why does in 2, the current ...
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IRF540 MOSFET overheating when used with IRS2104 driver as class D amplifier
Source:
https://www.infineon.com/dgdl/Infineon-IRS2104-DataSheet-v01_00-EN.pdf?fileId=5546d462533600a40153567633f727a1
I'm trying to drive a Powerhap 1919 haptic actuator (which I have represented as ...
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Flexinol Resistance Measurement in PWM-driven Control Circuit
I'm using Flexinol (a Nitinol shape memory wire that contracts when current is passed through it) as an actuator for a project. I have a functioning circuit that uses a PWM-controlled MOSFET to ...
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MOSFET switching with PWM
I have a question about MOSFET switching. I have a 126V voltage source and I want to drive it with a PWM signal. There will be a buck converter at the output of this MOSFET.
What is wrong with this ...
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Is having negative voltages on a MOSFET gate a good idea?
What is the purpose of C21 and D7 in the below circuit?
C21 is shown in the link provided to be an internal cap. However what effect does it have also placing a cap externally to the fet between the ...
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Problem with an Arduino DC motor controllable circuit
I am a material science student currently working on a project to build a simple circuit for controlling the speed of a DC motor. My goal is to avoid using motor driver modules by utilizing a MOSFET, ...
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Power latching circuit MOSFET is stuck ON
I've used a design I found online to for a power latching circuit.
My goal is to be able to shutdown the whole system using a pin on the MCU, and to turn it on by pressing a button.
User presses ...
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Hello, I am trying to replace a multi channel 12v switching relay board (automotive application) to something like a MOSFET or IC
Project details.
Automotive application 12V ignition system.
Currently using a 12V multi channel relay board in a NC configuration. All source channels (pulled low by ECU) are wired to the COM ...
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How to disable Tx line of USB to Serial converter?
I have a working system where using a CH340 based USB to Serial converter I am sending data over UART to an ATMEGA16 microcontroller at a baud rate of 9600. Now I am trying to implement an other ...
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Controlling 5 V / 2 A power with a photodiode (sensing red/green LED)
I am trying to design a circuit that will switch a 5 V / 2 A power on or off depending on voltage on a photodiode. If the voltage on the photodiode is below 40 mV, then it should be “ON”, otherwise “...
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Is My Magnetic Sensor-Activated Power Switch Circuit with Dual P-Channel MOSFETs Correctly Configured?
Is This Magnetic Sensor-Activated Power Switch Circuit Correctly Configured?
I'm working on a circuit designed to control power using a magnetic sensor and two P-channel MOSFETs. The magnetic sensor ...
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How to choose the right PMOS for inrush limiting application
I have a DCDC Buck-Boost converter circuit that needs inrush protection. I have looked around the internet and the resources for a viable solution and decided to use the following circuit from this ...
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Current-limiter circuit messes with voltage measurement in my 12 V battery balancer PCB, and I dont understand why?
I am currently designing a passive battery balancer for a battery pack with three 12 V batteries, the balancer needs to discharge the battery that has the highest voltage. The INA148UA difference ...
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Why is there 2.27V on the drain terminal of M1?
I have a circuit I am making to either switch two capacitors C1, C2 in parallel or in series. The intended behavior is when V3, V1 = 0V, V2 = 5V; they should be connected in series and the opposite ...
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How can I turn a MOSFET on and off with a PNP transistor?
I need to control a MOSFET (a Jiangshu JieJie JMSL0302AU) with an ATtiny1616 to turn a 40 A load on and off (without switching.) Could you please check if this schematic is correct? The ATtiny will be ...
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Electric moped PWM MOSFETs failure
I am back with my PWM moped project. Here is a link to my previous question if you're interested:
Advice about power MOSFET layout and heat management
Here is a quick summary of my circuit along with ...
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Is this design effective for ensuring that only one power source is active when two power sources are connected?
I found a design online that originally used a P-channel MOSFET, but I swapped it for an N-channel MOSFET. I'm not sure if this was the right choice or if it will work as expected. Any advice would be ...
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Use MOSFET to drive a high current source from a low-current digital logic output
I'm a beginner hobbyist here, and I'm in a bit over my head with MOSFET transistors. I want to control a fan with a microprocessor, and since it pulls more current than a digital I/O pin can drive, I ...
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Using Gate Threshold as Overvoltage Protection
I need to charge my lithium battery using TP4056 via a 5 W solar panel, open circuit voltage on that solar panel can reach 21 V, TP4056 can only handle a max voltage of 8 V.
I was thinking of looking ...
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MOSFETs keep shorting way below rated current
I'm currently building a small stud welder, which I'm trying to control with IRF1405 MOSFETs (rated at 55 V.) The circuit operates at 48 V and I'm controlling the current and welding time by switching ...
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What parameter decides MOSFET switching response?
I've been playing with some LTSpice simulations of some MOSFETs, the circuit is just an op-amp current source which receives a PWM signal to control the current. Below is some transient simulations of ...
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Placing MOSFET heatsink on PCB?
I'm printing a PCB for the first time, and I would like to know the best way to heatsink the MOSFETs; I'm using 4 RFD16N06LESM9A surface mount MOSFETS connected in parallel:
Would it be best to mount ...
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UART buffer using N-mosfet? [duplicate]
In this circuit, I expect that the designer needs a buffer stage for its UART (same ckt for tx and rx, but how should this work?
Thank you..
Edit: This is not a level shifter, UART is all the way (...
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MOSFET Power Control Problem: DFPlayer Circuit Not Working on PCB
I built a circuit that plays MP3 files and is controlled by an Arduino. I assembled the circuit on a breadboard, and it worked, but when I fabricated a PCB, the circuit failed. The problem is that the ...
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MOSFET Breakdown Voltage for this BMS circuit
I'm trying to design a BMS which has the following characteristics:
20 lithium-ion cells
in the discharging state, the cells are connected in series to develop a voltage of 84V max
in the charging ...
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Over Voltage Protection Circuit
I’ve been trying to figure out how this circuit works but I don't quite understand the point of D32.
D23 is a 33V Zener
D32 is a 15V Zener
D19 is a Schottky it just has the wrong symbol.
Q24 is a P-...
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MOSFET for level shifting - Gate to GND?
I am looking at the bottom left of page 13 of this schematics. It has a level shifter on a UART interface from 1.8V to 3.3V. For some reason they connected the Gate to GND though, which seems weird to ...
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Voltage Controlled High Current Source Mosfet selection
I am working on adjustable VCCS targeting 2 to 3A to my 0.5 ohm load.
According to my schematic:
I am controlling the current size through my load (H1, 0.5 ohm) by using DAC function of my MCU. ...
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Help review my schematic for a LiPo + USB power supply and charger
I've recently redesigned this schematic based on the feedback I've received on an earlier post.
Questions:
Will power source switching MOSFETs work in the configuration I'm using?
Will the tri-state ...
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555 as MOSFET driver always outputs high with input disconnected
I have been using a 555 timer as a MOSFET non-inverting driver for a few months now. It really is a signal amplifier for an Arduino Nano (which outputs 5 V) and it amplifies the signal into the gate ...
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Simple MOSFET LED switch - interference when components are placed close together
A motorcycle daytime light controller outputs 100Hz standard PWM waveform to dim a power LED module. The output waveform is for dimming control only, so a switch is needed to handle the LED current (2....
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High current voltage controlled current source MOSFET selection
I am working on adjustable voltage controlled current source (2 to 3 A) for my project.
I tried different NMOS for the projects, but they all burned.
In my application, the resistance of my load is ...
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Determing the line and load regulation of a Zener MOSFET regulator
I am working on a circuit involving a bridge rectifier, a smoothing capacitor, and a Zener-MOSFET regulator. I need help finding a mathematical representation of line regulation and load regulation of ...
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power switching p-channel or n-channel mosfets
I want to have Vbat enter Vcc when Vdd goes Low. The schematic I'm following is using a P-channel mosfet with Vbat connected to drain. I feel like this is wrong and I should either use a n channel ...
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What happened to MOSBD?
There was a time around 2008 when TI and Toshiba annouced new MOSBD aka FETKEYs. These MOSFETs come with an internal Schottky Diode to reduce free wheeling loss during dead time. See Toshiba Mosfet ...
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Transmission Gate in LTSPICE
I am trying to simulate a transmisson gate in LTspice but regardless of the state of the clock it keeps giving me the exact copy of input as an output. I tried inverting the clock with a inverter but ...
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