Questions tagged [powermosfet]

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56 views

MOSFET as a switch: operation region during Rise time

In the below picture, during the time period Tri the drain current Id starts increasing linearly wrt gate voltage Vgs and the voltage Vds is clamped to Vd since the drain current hasn't yet taken up ...
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0answers
40 views

What will happen if a MOSFET switch circuit is run without the source?

I have a situation where I have to supply the power to the MOSFET gate drive circuit permanently even when the main switch for source battery is turned off. It is because of the fact that the drive ...
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34 views

Controlling DC motor by MOSFET

I am trying to control the speed of a DC motor speed by varying Vds and keeping Vgs constant at 9volts by potentiometer, but I am not getting appropriate and smooth control of the DC motor this way. ...
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1answer
157 views

What is the difference between an inverting and non-inverting MOSFET Driver?

I'm looking for a High Side MOSFET Driver (have the MIC5014/15 in mind) to drive an N-Channel MOSFET, and I noticed that this IC had a Inverting and Non-Inverting variant. What is the difference ...
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61 views

Getting More Power out of an H-Bridge

tl;dr: how to design an h-bridge to give more power to motors. pre-fab circuits are not an option. Hi, so for my electronics class we have to build robots from scratch. So no pre-fab circuits (with ...
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4answers
249 views

What is the general criterion for selecting a MOSFET voltage and current rating?

I've used an N-Channel MOSFET (IRF540) rated at 100V 28A as a switch with a 54V load and current source that maxes out at 20A. The switch worked however, using the load for a while resulted in MOSFET ...
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0answers
172 views

Why does MOSFET get damaged when used as a switch in a RF remote control circuit?

simulate this circuit – Schematic created using CircuitLab Update: The MOSFET gets damaged when not running the motor even once. Maybe even without connecting the motor at all. There is an alarm ...
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1answer
78 views

N-channel mosfet turn constantly on after a while

Hi; N-channel mosfet (Q4) work fine for couple of time and suddenly turn on constantly. I changed Q4 multiple of times and each time it work for couple of time and suddenly turn on constantly. the ...
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1answer
79 views

How to connect low power components to high power component?

I have a fairly standard circuit: I am controlling a 12V starter motor + 12V car battery with an Arduino PWM signal. I have an array of 4 MOSFET's to connect the low power circuit (Arduino) to the ...
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0answers
36 views

What is wrong with I_drain?

After adding an inductive load at the switching node of the half bridge circuit, the drain current keeps increasing. Why is this so? What have I done wrong in the circuit? I first tried to put L,C,R ...
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1answer
29 views

Is my circuit to power 38 kHz LED matrix correct?

I'd like to send 38kHz signals to an LED matrix to pulse 5V IR LEDs. The intention is that a lot of IR will be reflected when a finger is placed on a translucent 3mm acrylic panel above the LEDs. The ...
3
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1answer
92 views

Help identifying this MOSFET

Trying to figure out what this is, and suitable replacements. Markings are "1 Wt 77" Cannot seem to find anything. Edit: I removed and sized it today, looks like 2.04 mm square package, ...
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1answer
89 views

Back-to-Back N-MOSFET inrush current limiting

I try to develop an application where I need to switch 55V at 20A in both directions using MOSFETs. Because of the high current, I decided to use N-MOSFETs (because they are available with lower rdson)...
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3answers
416 views

Calculating MOSFET gate current at certain PWM frequency

I want to power the gate of an IRLB3034 MOSFET by a PWM output from an arduino. I know that the current required to charge the gate increases, the higher the switching frequency is. With 5v powering ...
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1answer
71 views

Multiple devices on a heat sink

I am mounting multiple devices (TO-247) on a large rectangular heat sink. What difference does it make to mount them on the edge of the heat sink vs. the middle?
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59 views

BMS won't output voltage despite good LiPo Cells

I have an 20 cell LiPo battery pack that is healthy at 80V in total, the BMS uses 12 MOSFETs in parallel to switch the negative terminal and they all seem healthy but won't switch on, so I can't get a ...
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0answers
22 views

Vgs for MOSFETs in BLDC circuits

I'm confused about how N-channel MOSFETs operate in BLDC circuits. Say we had MOSFETs that are being driven with Vg = 10V, and DC+ is 36V. Say we have Q1 and Q4 on at some instance (Through phase A ...
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1answer
234 views

Simulation isn't working for high voltage amplifier

Been trying to simulate on multisim a circuit I saw about high voltage amplifier: The input is 8 Vp-p and 100Hz and reached to output of 1800 Vp-p and 100Hz. The publisher mentioned he used the ...
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1answer
67 views

What is the R-C Feedback to this FET?

I'm studying this RF Power Amplifier and I'm curious about the drain-gate feedback shown as R3 and C6: What is the purpose of the R-C feedback? What is this mechanism known as?
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2answers
62 views

High Power Mosfet

I am developing a DC to DC converter(40V -> 12V) circuit using Mosfet. As I am using solar two panels rated 375 Watts (Max 10Amp,37.5V) each, so the convertor needs to handle 750 Watts at peak. ...
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0answers
179 views

Replacement for fnk3070pa

I have a JR1738RX-12V remote control system in my child 4WD car. We noticed that it's too slow/weak so we decided to put 4xRS-570 motors to give it more juice but they are 65W compared 45W from ...
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0answers
61 views

How to increase Vdss of power MOSFET?

I want to build a Tesla coil with mains voltage. I found a schematic online but it uses an irfp460n MOSFET which can handle 500v (Vdss) but I only have couple of irfp260n and irf250n MOSFETs with 200v ...
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0answers
41 views

Robotics Dual Battery System

Background: I'm designing a general purpose robotics controller. The controller is split into two boards, a power board, and a computation / data handling board. The controller is intended to be ...
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0answers
79 views

How to calculate snubber for switched inductor?

I'm driving inductive load with PWM and my MOSFET can not handle hard switching without reduce dv/dt ramp between drain-source. So I need to add RDC (resistor-diode-capacitor) snubber, but I don't ...
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3answers
129 views

Level Shifting a MOSFET

I have a high current low voltage MOSFET I'd like to drive with a higher voltage and a micro to reduce power losses through it. I built this circuit based off the typical level shifting designs. The ...
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3answers
70 views

Mosfet damage (internal shorting) with zero gate voltage

I am working on a switch for my quadcopter. I designed a basic circuit with MOSFET as the switching device. I am using an LDO to supply the gate voltage to the Mosfet. The circuit diagram is attached ...
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1answer
70 views

Verifiying what Vgs means

I am looking for a MOSFET that is capable of dealing of a max pulsing voltage of 60A(between drain and source) and came across these 2 MOSFETS https://www.onsemi.com/pub/Collateral/NDPL070N10B-D.PDF ...
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1answer
54 views

How to identify duplicate vs original FETs

I am really confused about this topic. Wheather it's ok to use duplicate MOSFETs or not. Say for example my application requires to handle upto 20 amperes of motor current. Is it ok to use 100A or ...
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4answers
2k views

Kelvin Source Terminal on MOSFETs

On MOSFETs with multiple source pins, is the so-called "Kelvin-connected source pin" connected any different internally? Or is it just like every other source pin? EDIT: Just to be clear, I ...
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0answers
87 views

Can anyone help with designing a MOSFET load switch

Can anyone help me design a load switch using the Infeneon IPP120P04P4L p channel MOSFET and the necessary filter components? I would like to use the Texas Instruments ULN2803A darlington driver to ...
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0answers
52 views

Calculating MOSFET gate current with \$Q_\text{total} = I_\text{gate} \cdot t\$

Hi I am using the MOSFET IRFP4368. I want to use the equation $$ Q_\text{total} = I_\text{gate} \cdot t $$ to calculate the required gate current of my MOSFET driver. I have my total \$Q_\text{total}...
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1answer
115 views

Need help understanding the mosfet trailing edge Dimming

I am working on a circuit to control AC loads up-to 1.5KW by using Mosfets(FCHD125N65S3R0-F155) Circuit is I have few concerns The current is flowing through the body diode of Q2 for positive half ...
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2answers
274 views

H Bridge runs for few minutes and MOSFETS start smoking

I have created an H bridge as shown in the schematic below. PWM signal to the MOSFET driver is given by a microcontroller running on 5V. The MOSFETS are screwed to heat sinks. To control the motor ...
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1answer
262 views

MOSFET H-Bridge FAN7388

In this question Fan7388MX on StackExchange, someone asked how to choose the resistor values for FAN7388MX MOSFET driver. Datasheet: https://eu.mouser.com/datasheet/2/308/FAN7388-D-1805672.pdf The ...
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3answers
107 views

How to digitally control a MOSFET? [closed]

I'm trying to make a temperature controller for peltier module using MOSFET. The peltier uses 3.3 to 12 volts and 15A. So far I've only come across a way in which the circuit uses a potentiometer at ...
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2answers
217 views

MOSFET gets hot in an Op-amp MOSFET-based constant current load build

I've made this schematic following the circuit steps in this site: and after running the output with just 0.1-1A (which works ok according the input setting and current reading seems correct) but the ...
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1answer
116 views

Why do bare die chips (MOSFET) have a maximum storage temperature?

As far as I understand, a chip in general and a MOSFET in particular has a maximum operating temperature (let‘s say 125 °C or 150 °C for Si) because above that temperature the risk increases of ...
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2answers
207 views

Oscillations in voltage-controlled current source with MOSFETs and opamp feedback — Why?

I have a circuit that should operate as a voltage-controlled push-pull current driver, able to source or sink at least 2A (into a 1 ohm load). It has unexpected oscillations on the output current. ...
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1answer
74 views

P-channel MOSFET switch - very high Rdson

I am trying test my p-channel mosfet (IRF9Z34) high side switch on load. On circuit simulator I get the result I expect, Rdson (VM1) is low and load current is 1.4A. (In the target system the gate ...
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3answers
83 views

what is causing this ring effect on my MOSFET testing circuit and how would I be able to calculate the MOSFET power losses?

So I have the following circuit This is the data sheet for the MOSFET enter link description here Using equations, I worked out what my Rgate to be 2.36 ohms. where Rtest was a 470ohm ceramic block ...
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5answers
429 views

Improving dV/dt turn-on immunity of a mosfet without increasing turn-off time

I'm designing a solid state battery disconnect switch and I want to improve the mosfets' turn-on immunity (high dV/dt on Vds) without impacting the turn-off time. I don't really care about the turn-on ...
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1answer
88 views

MOSFET Voltage Spikes

I have a voltage source that has a square wave between 20V and 35V with 12.5khz frequency. Even i fully close the MOSFET, it is still conducting in rising and and falling edges of voltage source. How ...
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1answer
77 views

Electronically Actuated DPDT Switch?

I am trying to be able to dynamically switch two wires on a brushless motor ESC for a Quadcopter. The plan is to wire an arduino to the flight controller so that I can program it to switch the ESC ...
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2answers
867 views

Upgrade BLDC motor controller (ESC) to higher wattage (replace mosfets/shunt)

I was wondering if I could upgrade my current bldc motor controller (three phase motor)(*) to a higher wattage/output power by doing the following modifications: Replace mosfets with higher power ...
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3answers
847 views

Removing voltage spikes and overshoots using power MOSFET as switch and 555 timer as pulse generator

I'm trying to turn on a power LED using LM555 timer as input signal of IRF630N N-channel power MOSFET as Fig1. Fig1. pulse generator and switching circuit. Here is the output of LM555 Timer (Not ...
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0answers
29 views

SIZING steps and Interpreting Mosfet datasheet

After reading those Interpreting Maximum Power of a MOSFET from the datasheet How to interpret Vgs(th) min/max in a MOSFET datasheet? https://www.infineon.com/dgdl/Infineon-...
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2answers
116 views

Power MOSFET internal diode: when does it conduct?

So I'm currently studying power MOSFETs and I'm getting a bit confused about when and how it conducts current. Let's start with the normal MOSFET functioning. I'm considering a n-enhancement type ...
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0answers
171 views

Mosfet control Rds on , and Vgs

I want to know how to calculate Vgs , assuming load current Id is constant , Vd = voltage of battery is constant , and fet is operating in thermal stability region , so there is no thermal runnawy , ...
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0answers
42 views

How much does the gate charge of a MOSFET change over lifetime?

Is the total gate charge of a silicon power MOSFET changing over lifetime, as long as it is used inside its rated operation conditions? I am using a SIHB6N65E (650 V, 600 mOhm) were the datasheet ...
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1answer
184 views

High side MOSFET driver with transformer

I am reading the application note " Fundamentals of MOSFET and IGBT Gate Driver Circuits" written by Texas Instrument. In order to control High Side MOSFET, the application note suggests to use this ...