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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26 views

what is the tempreture at which the thermal limit of an amplifier is reached

Introduction: I am upgrading a "power amplifier" that a fellow engineer has designed , my job is to add thermal protection against failure in prolonged use ( or if operator miss use). The ...
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1answer
38 views

What type of FinFET is this? It is an example file of Sentaurus TCAD

As as I am totally new to TCAD software, I'm unable to parse the code. My doubts are as follows: 1) Whether it is a SOI Finfet? 2) Why am I only able to see half structure at the last node? ...
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0answers
59 views

Audio POT with FET and PWM

I've been trying to build a simple audio pot to be controlled with PWM with an arduino, but I'm not sure why it doesn't work. I could do it with a LED (not directly which is simple, but with a FET), ...
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1answer
59 views

Help in chosing Mosfet [on hold]

we have a circuit using a DAC http://www.analog.com/media/en/technical-documentation/data-sheets/AD5593R.pdf so basically the DAC output voltage is from 0 to 5V This DAC needs to finely control ...
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2answers
38 views

Mosfet driver(Pin configuration)

I would like to know what Vcc(supply voltage) and Vin(input voltage) do on Gate driver. Here is the datasheet. http://www.ti.com/lit/ds/symlink/tps2813.pdf
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3answers
178 views

What design decisions must I make to select a suitable P-Channel MOSFET

I need a PFET with a logic level gate to trigger a power connection to a hobby servo that pulls more current than my MCU pin can handle. The requirement is simple but I'm trying to understand how to ...
0
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1answer
49 views

Driving 4 100mA motors using GPIO pins and BS170s

I'm trying to drive 4 tiny vibrating motors which draw 100mA at a maximum of 5V. I need to control them using PWM from the GPIO pins and would like to accomplish this in the smallest form-factor ...
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1answer
64 views

How MOSFET gate capacitances (Cgs, Cgd) are calculated?

I have read somewhere that the gate capacitance (Cgs, Cgd) of a MOS is calculated as below: Strong inversion: Cgs=(2/3)Cox.W.L + Cov Non-saturated: Cgs=Cgd=(1/2)Cox.W.L + Cov where Cov is ...
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0answers
27 views

Switching ON/OFF the enable input pin of TPS63060 DC-DC switching converter

I need to make an ideal switch to turn ON/OFF the EN pin of a Texas Instruments TPS63060 buck-boost converter. Now, my PCB has got a MC14093B "Quad 2-Input “NAND" Schmitt Trigger" to drive the gate ...
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0answers
16 views

Replace hybrid-pi model with proposed Thevenin model

This lecture (page 10) shows how to replace hybrid-pi model with proposed Thevenin model. Could you tell me how to calculate \$A_{v}\$ to get the result as in the page?
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2answers
42 views

Raspberry Pi + IRFZ44N to control a 5050 RGB LED strip: current seems to be limited

Introduction and General Question: Scalability I have assembled very simple circuitry to successfully control one RGB LED strip. I have also managed to improve slightly its yield. However, when I ...
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2answers
95 views

What is the purpose of this bias resistor?

I am unsure what the following statement on page 4 of this application note (Over Voltage Protection Circuit for Automotive Load Dump) means. Resistor R4 provides a small amount of bias to Q2 ...
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0answers
105 views

Mosfet keep circuit closed (vape mod)

Hello i made circuit with IRLB3034 mosfet for using vape mod with low current rated button, but i have problem - mosfet is firing itself when i plug battery in and its overheating (coil is 0.5ohm). I ...
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2answers
64 views

Multi level logic in transistor level. Possible?

I am currently studying the MOSFET transistor for Digital CMOS IC design. There, the noise ratio is defined and the 50% margin is assigned for a logic HIGH and LOW. Taking the noise into account, do ...
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1answer
45 views

What can I replace a BSS138 N-Channel MOSFET with?

I'm replicating this level shifter by Sparkfun but they use a transistor that I don't have. Frankly, I know next to nothing about transistors so reading the specs is way over my head at this point. ...
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7answers
82 views

Why should we set input source equal zero for calculating output resistance of common source amplifier?

This lecture (page 10) gave derivation of common source output resistance. What I don't quite get here is why we should set the input source equal 0 for calculating output resistance. Could anyone ...
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3answers
70 views

Open circuit resistance in common gate amplifier

I am reading about common gate amplifier on this page and there is a small signal model that I am a bit confused. The common gate amplifier and its small signal model is shown below. As you can see ...
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5answers
886 views

Is there an ideal PWM frequency for DC brush motors?

I'll be using a microcontroller to create a pwm signal for motor control. I understand how PWM and duty cycle works, however I am unsure about an ideal frequency. I do not have my motor in yet, so I ...
0
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1answer
98 views

mosfet bootstrap explained [closed]

I'm trying to get a hold on bootstraps for high side n-mosfets. as i currently understand it, it works somewhat like this: when pwm is high, mosfet is closed and capacitor is loaded to 12V. when PWM ...
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1answer
26 views

Can you use less then the rated current on a High Side Smart Switch such as BTS555

I often see Minimum Current listed on the data sheets of some Smart Switches, Power distribution Switches etc. For example in the data sheet of BTS555 it states that the minimum current is 128A so ...
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2answers
57 views

Half Bridge with dual powre supply and two N-channel Mosfets?

I wanted to ask (can't find a straight answer) if it is possible to make a half bridge with two N-channel MOSFETs (I have the solution with one nmos and one pmos, but I'd like two nmos). For the ...
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1answer
36 views

Control an inductive load with VCO

I am trying to tune this circuit, dimensioning the values of resistors Ra,Rb and the capacitor C... The circuit work in this way: a voltage Vin regulates the current flowing in the inductor, via the ...
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1answer
67 views

Use Transistor As Mosfet [closed]

I want to make mazilli ZVS Flyback driver based on this tutorial www.instructables.com/id/ZVS-Driver I needed IRFP250 mosfet for making it I cant find it locally.In the schematic picture they said ...
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0answers
49 views

Mosfet LED switch protection

I'm designing a Mosfet based switch that uses a low current reed switch to control either 24V or 12V LED strip lighting. Having some issues with the protection circuits. My specifications are as ...
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1answer
59 views

How are few-nanometer multigate MOSFETs fabricated?

Intel and IMEC came up with multigate MOSFET designs with channels as narrow as new nanometers. Which methods/techniques/machines are used to pattern/fabricate such small features? (source) (source)
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2answers
42 views

Electronic circuit analysis: Find V_out with several MOSFETs

I have a question about an exercise from my electronic circuits class, number a): Find an expression for the large signal V_out at DC. Since it is DC, we can ignore the capacitor, it will act as an ...
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2answers
315 views

Wires from car battery to solenoid catching fire after connecting a second solenoid

I have two solenoids connected to my AVR and car battery: simulate this circuit – Schematic created using CircuitLab But when I start switching them the circuit burns up (literally there ...
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3answers
219 views

What causes this knee in my MOSFET drain voltage drop?

FINAL UPDATE: Understand a previously mysterious power MOSFET switching waveform wiggle! @Mario uncovered the root cause here below, distinctive to so-called VDMOS devices, typical of many power ...
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3answers
94 views

PMOS as a switch

I am trying to get a PMOS(BS250) act as a switch according to following diagrams. But the motor(its a servo) doesn't work no matter what signal I give at the gate. Any inputs on why this might be ...
0
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0answers
31 views

Operating frequency of RD15VHF1 and 1N5822

I am currently building an inverter circuit and a rectifier circuit. I proposed to use RD15VHF1 and 1N5822 in the circuit because my target is to operate the circuit in the range 500kHz to 1.5MHz. In ...
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0answers
98 views

Simple resistance based water sensor works in stagnant water but blows out in running water, under faucet

The circuit is intended to flash an LED every 7 seconds when there is no water and to flash it very rapidly (time period less than 1 second) when it "senses" water. It all worked well when tested with ...
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2answers
145 views

Double polarity pulse with one single power source and virtual spdt switch

I have a problem in the design or my circuit. I need send data at a maxixum bitrate of 12000 bits /second. The high value should be +12v and the low value should be -12v providing at least 35mA of ...
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0answers
62 views

Why does my MOSFET output depend on source-drain bias sweep direction?

I measure my MOSFET at fix gating voltage (on-state). When I sweep source-drain bias from 1 V to 0 V, current decreases from \$10^{-6} A\$ to \$10^{-12} A\$. But when I sweep source-drain bias from 0 ...
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1answer
49 views

High current motor control

When designing for relatively high currents, e.g. 6-10A, what is the standard practice for motor control? Is it to construct an H-bridge out of discrete components, to use integrated half bridges, or ...
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2answers
80 views

TO264 package at 100 Amps

I'm trying to design a BLDC motor controller rated to run a 200kW electric motor, 240v dc ~833A. Looking at MOSFETs I've found a TO264 n-channel which is rated for 500V 100A. How are the legs not ...
1
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1answer
49 views

Understanding MOSFET ouput characteristics on a log-log scale

I am a second year BS Electrical Engineering student, and I am working on making an autonomous robot in my summer vacations, nowadays. Right now I am designing an H-Bridge using discrete components ...
0
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2answers
103 views

Mosfet not passing enough current using a microcontroller and 2 power supply

I have made this circuit: Ignore "high voltage circuit" is not used. It's a prototype built in a breadboard with jumpers, and i have a problem with the mosfet "IRL540N", is not passing the optimal ...
0
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1answer
86 views

Relay Vs MOSFET or IGBT

Curious on your thoughts for an application and the pros and cons of using a relay or a MOSFET or IGBT. The application involves switching a 96V lead acid battery pack on and off for periods of 5 ...
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votes
1answer
41 views

Reverse Current in N Channel Power Mosfet

I am designing a bidirectional current source to drive a large (~60A) current through a large inductive load (100's mH) and facilitate very fast switching times (as close to an 1A/us as possible). My ...
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3answers
101 views

A mosfet switch for PWM signal

I was wondering if my circuit will work. The 5V signal is coming from a microcontroller, based on a condition. If its 1(5V) I want the PWM signal to be received by the motor. If its 0, the motor ...
0
votes
1answer
45 views

What characteristics of a MOSFET should I be looking at? [duplicate]

I'm trying to determine a MOSFET for a circuit I'm building which will drive the gate of an N-channel MOSFET at 3.3v with an available current 40mA (**this will be driven using PWM at 4MHz), the ...
6
votes
1answer
230 views

Simulation model for floating gate

I am designing a non-volatile memory cell and foundry does not have model for floating gate . So I used the Voltage controlled current source to mimic floating gate. For output characteristics, I ...
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1answer
42 views

MOSFET Replacement for PNP BJT in a 12V switching circuit

I used a PNP to control 12V in circuit. as follows System_Load/2 is 12V DC, MIC1_PWR is the output and LCD_W2/1 is the control signal. This circuit would work fine if the control signal's High is ...
0
votes
1answer
82 views

Current limitations of a MOSFET [closed]

I am using IRFZ44N for supplying current to the RGB LED strip. The current that is supplied by the three MOSFETs for the three corresponding colors (R-G-B) is not uniform and much less than required ...
1
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1answer
55 views

N-type channel mosfet

I try to explain how a n-channel mosfet works. But as I try to explain there is an ambiguity that I can not understand. As I read many books and searched in the internet does not say anywhere clearly ...
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2answers
76 views

Charge pump circuit with one MOSFET

This is an example of charge pump from MOSFET Models for SPICE Simulation: Including BSIM3v3 and BSIM4 by William Liu. Could anyone explain why \$ v_D = \frac{(v_{IN} - V_T)}{2} \$ here? Why \$ V_T \...
4
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1answer
59 views

Vgs and semi-active rectification

simulate this circuit – Schematic created using CircuitLab I'm new to the world of mosfets and am trying to learn them better. Would this rectifier IC be safe for input voltages of 24V if Vgs ...
4
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3answers
181 views

How to increase mosfet switching speed, and decrease switching losses?

I hope this is not a too broad question, but what are the best practices to achieve fast switching on a MOSFET driven by a PWM signal? My current knowledge tells me I can do two things: 1 - To use ...
2
votes
1answer
55 views

Class B power amplifier using only Nch FETs

I'm building a combined linear regulator/electronic load. When the output is lower than the supply Q3 acts as a linear regulator and when the load tries to pump power back the other way, Q6 acts like ...
0
votes
1answer
100 views

How can CAN transceivers ouput CANH=3.5V and CANL=1.5V?

When sending a dominant bit (0bit) on the CAN bus, I understand that CAN transceivers output CANH=3.5V and CANL=1.5V. But when looking at the schematics of a CAN transceiver, I do not understand how ...