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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2answers
15 views

how to see dc operating region names in cadence DC annotation for MOSFET

How do I see the operating region names like "active, saturation" in cadence for MOSFET. I remember getting it by setting up View> DC annotation> Setup > selecting DC operating region > Display > ...
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0answers
51 views

Continued Problem of the hot MOSFET in a SEPIC converter

This question is based on the one that I previously posted in: MOSFET gets unusually hot in a SEPIC converter Since that time, I have made a lot of changes to my circuit based on the feedback given ...
8
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3answers
131 views

How many MOSFETs can we safely parallel in condition of very high currents? I had problems with a motor application at 48V 1600A

I tried with some configurations in which 16+16 MOSfets of 240A each (really they are case limited to 80-90A because of source terminal, but i doubled this termminal with a very thick copper wire for ...
0
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3answers
32 views

Using 3N128 mosfets as 12V controller with microcontroller

I recently found a bag of 3N128's at a yard sale, coincidentally, a couple days after I saw this video on YouTube about controlling a 12V motor with a mosfet, car battery, and arduino: ...
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1answer
45 views

How to do DC Analysis for a Common Source Biasing Circuit using NMOS

I am having a lot of trouble with this specific problem. I want to find Vg, Vd, Vs, and Id for this specific common source biasing circuit that has an NMOS. I have these values given: Vdd = 9V, k/2 = ...
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0answers
49 views

How to drive a MOSFET from AC wih max efficiency?

Short version: if I needed to drive a MOSFET from mains AC, that will be switching (PWMing) mains AC as well, and needed to do this "fast and often"* how should I derive the power to drive it's gate ...
0
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1answer
70 views

Switching between two power supplies with a P channel Mosfet, Is VGS or VDS a problem?

So I am using the following circuit to switch between VIN 0-30v and USBVIN 5v. I thought I found the ideal solution until I realised the FET in the schematic only has a max VGS of 8V. But I don't ...
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1answer
35 views

MC34063 P-MOSFET driver?

I've got a successful buck converter design using an LM3485. It's got a MOSFET gate driver output pin that swings between Vin and Vin-5V - perfect. My MOSFET is a SQ1431EH-T1-GE3. It has a maximum Vgs ...
6
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1answer
74 views

A naive solar panel maximum power point control circuit

I am fooling around with a solar panel, just to try stuff and learn in the process (not trying to produce something I would actually use). Its placement is very far from optimal - vertically behind ...
0
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3answers
79 views

Mosfet Power Dissipation

I'm trying to find power dissipation of my mosfet when I pull 17.5A. I'm using CSD18542ktt. Can anyone help me what equations can i use. I have calculated the max power using the following equation. ...
0
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0answers
78 views

Replace BJTs with MOSFETs

Is there anyway to replace this Darlington BJT amplifier pair in this signal detector with MOSFETs instead? Perhaps using MOSFETs to amplify the current instead. I am trying to replace this Darlington ...
0
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2answers
70 views

2N7000 behaviour explanation

I recently bought a 2N7000 transistor and though it was a cheaper replacement MOSFET compared to the STP55NE06 as I didn't need to handle high voltages and high currents. However it acted very ...
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0answers
35 views

Series Gate Resistor needed at low Capacitance?

even though this question has been answered before for various scenarios, I would like to ask for a generic advice. So I want to drive a certain resistive load from a microcontroller pin. Let MCU be ...
0
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2answers
64 views

Logic level MOSFET switch

I am trying to use a FET to switch on a boost converter. simulate this circuit – Schematic created using CircuitLab From reading I have found that people like to use IRFML8244TRPBF for ...
3
votes
2answers
58 views

What is the use of the line connecting drain and gate in current mirror using voltage bias?

I am confused about current mirror. Given this circuit simulate this circuit – Schematic created using CircuitLab it makes sense to connect the drain to the gate in order to make their ...
0
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3answers
69 views

N-Mosfet switch circuit strange behavior laboratory power supply

I'm dealing with an N-Mosfet switch circuit to control, through PWM, the temperature of a heater resistor. The mosfet is a IRFS7430-7PPBF. The load is driven at 12V and has a power rating of 80W. ...
0
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1answer
37 views

Basic doubt regarding attached circuit

Could some one give me a quick answer why voltage drop at the drain of M1 is 4.611V and not 5V. Since the N-FET is non conducting, it acts as a open. similarly the diode should also be off and open. ...
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0answers
74 views

100Khz 150W LED Switching

My test Circuit is 5V VCC + LED + n-MOSFET(Controled by OPAMP for constant current) + n-MOSFET(For ON/OFF) +(feedback)+ Shunt Resistor + GND. 5V/30A SMPS. If there is no n-MOSFET for ON/OFF. It's just ...
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0answers
27 views

Deriving small signal gain for specific circuit

I am working on a small question regarding small signal gain Assume V1 is DC, V2 is small-signal AC source. What is the gain Vy/V2 from V2 to Y ? How would I proceed on this ? I got a hint that ...
3
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2answers
95 views

Is it safe to drive P-channel MOSFET gate directly from an MCU pin and 12V pull-up?

I was wondering how reliable it would be to drive a P-channel MOSFET directly from a micro-controller pin like this: simulate this circuit – Schematic created using CircuitLab When I ...
0
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0answers
21 views

How to plot ac load line?

I am learning how to plot the load line of the BJT and MOSFET .But I find some difficulties when drawing the ac load line In this BJT circuit For the dc load line 18=Vce + ReIc(1+1/β) Ic= ...
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0answers
28 views

Input and Output Load Lines

In parts b and c, what is the input and output load lines? Thanks
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0answers
60 views

Parallel high speed and high current mosfets

In order to speed up switching times and reduce I2R losses, is it worthwhile to put a fast switching (but high RDSon) fet in parallel with a low RDSon (but slow witching and high Qgs) fet? That way ...
0
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1answer
35 views

How to get the same output signal but with an increased capacitive load?

I'm designing a CMOS circuit of a VCO and it works perfectly fine when tested independently. Now when I cascade an other block like a divider to it, the output isn't the same as before. Rather its ...
0
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1answer
51 views

LED switch with externally controlled current from sinking output

My device has sinking output (Vcc=3.3V), the LED current (and voltage) is controlled by another device (a voltage controlled constant current source) as indicated at VLED. The LED IV curves (as ...
0
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1answer
35 views

Switching Fuel Pump through MOSFETs instead of Relays

I'm a member of a Formula Student Team of VIT University, India. We currently are building a power control board where our Engine Control Unit switches the relays which drive the Fuel Pump which ...
0
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1answer
28 views

Common drain stage/Source follower circuit analysis

I have been recently working on different type of MOS amplifiers and the following are my main doubts, 1) When we have a high gain stage such as the common source stage we use the output of this ...
6
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4answers
555 views

What is so special in the power MOSFETS IRFD120 and IRFD110?

I was trying out a hobby project and I was using the IRFD120 and IRFD110 power MOSFETs to control a motor. The transistors worked pretty fine and we simply ran out of them. When I went to buy some ...
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1answer
52 views

0-5V PWM to analog 0-24VDC voltage with MOSFET

Im having trouble understanding how or if it even is possible to regulate a voltage with a MOSFET. I want to regulate an output voltage of 0-24VDC 0.5A(continuosly) with the duty cycle of a 0-5V 1kHz ...
0
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3answers
66 views

Directly driving 5V source MOSFET H-Bridge with 3.3V logic

I am trying to design a H-bridge circuit for my project to drive a thermoelectric cooler (TEC). Basically, I am trying to control the TEC with a voltage source driven by PWM. Now the problem is, I ...
0
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2answers
40 views

How to find value of beta = (mu*Cox)(W/L)/2 of MOSFET in ngspice

How to find value of \$\beta = \frac 1 2 \mu \cdot Cox \cdot \frac W L\$ of MOSFET in ngspice? Is there any command that displays that? The 'show' command displays many parameters but it doesn't ...
0
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1answer
24 views

Small signal model for Mosfet…unsure as to whether its common drain, gate or source

I am looking to solve for the input/output resistance in the small signal model for the below circuit. But, I am unsure as to how to set up the model as I can't tell if it is common gate/source/or ...
0
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4answers
115 views

Oops! N-channel Mosfet on sinking output

I have designed a simple circuit to drive LEDs using a MAX6964 I2C LED driver/GPO chip. Unfortunately, I somehow missed missed that the outputs are open-drain current-sinking outputs. This is not ...
0
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2answers
42 views

I need to be sure that these are right values for MOSFET 2N7000

I made A circuit for test mosfet in proteus But according to datashet the values are incorrects. I need your help : Is it normal these values ? For example : V(gs) in my circuit is 4 volts and ...
1
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1answer
30 views

Transient response to rectangular impulse of a cascode common source amplifier

There is a cascode amplifier seen on the picture below. A rectangular pulse with amplitude of 10 mV is sent to the input. Due to large negative amplification gain of the cascode amplifier, output ...
0
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1answer
112 views

Best way to control power with MCU gpio pin

This is my circuit. An MCU gpio pin should control the power of another IC. Because the component requires more current than the gpio pin can drive, an N-Channel MOSFET is used. This is IC has no ...
0
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1answer
27 views

Solar MPPT charging circuit

I'm new to this solar stuff. I bought an 20W solar panel. I'm planning to upgrade to 100W. But the problem is I've searched about mppt systems and get bit of confused. So please correct me if I'm ...
0
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1answer
25 views

Limit the current of a fixed voltage via MOSFET+PWM

I have a SMPS which I would like to current limit. The current limiter should have a negligible voltage drop when not limiting (say, <0.5%). I thought of inserting a MOSFET and a hall-effect ...
1
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2answers
53 views

What is the purpose of these extra 'level shifter' BJTs on a MOSFET H-Bridge?

I am working on a 2WD Arduino project. Making the H-Bridge myself, and not using an IC like the L293 is a requirement for my project. After searching a while, I came across this, and based on this I ...
0
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1answer
39 views

Connecting controller to IRF540N

I'm trying to turn on my LED's with IRF540N mosfet. Here's my plan: I'm not totally sure on the resistance. How can I calculate the resistance required between the base and the controller and ...
1
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2answers
56 views

MOSFET as a VCCS or an variable resistance

I am a bit confused. In saturation region, sometimes, an MOSFET is called voltage-controlled current source and sometimes it is called variable resistor where its resistance is controlled by the ...
1
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2answers
70 views

MOSFET-N as a switch for several ICs

I want to use MOSFET-N (MTM232270LBF) as a power switch for several ICs in my project. It should poweron the devices when logic level is high (3.3V) and poweroff when 0V. I want to ask you if ...
3
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1answer
39 views
0
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1answer
34 views

Mechanical Contactor for High Voltage DC - Substitute with Semiconductor

To switch 1kV DC at 5A, I usually use a mechanical contactor (<- Wikipedia) that switches both highside and lowside of a resistive load. Any suggestions on a semiconductor (or non-mechanical part) ...
0
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0answers
35 views

Li-ion protection circuit: MOSFET connection

I've checked a lithium ion protection circuit and found out that the D1 and D2 terminals from AO8810 are connected: But checking AO8810's datasheet I find that the MOSFET's drains are internally ...
1
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1answer
76 views

Push-pull configuration over single mosfet

I'm dealing with a simple application in which I need to drive a pure resistive load and to control it by voltage. I control the load through a pwm signal coming from a microcontroller in 5V logic. ...
3
votes
1answer
69 views

Why are the dimensions of a floating gate layer in a MOSFET so thick?

For a floating gate MOSFET, in order to make the control gate work you have to(generally speaking) make the oxide layer thin(~100 Angstroms) as well as the ONO(Oxygen nitride, acts as an insulator) ...
0
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1answer
42 views

Calculating the input current drawn by a MOSFET driver

I am using a PIC32MZ's OC pins (PWM mode, fault disabled) as input to a dual MOSFET driver (ISL89163 A). I need one OC pin to drive 3 drivers i.e 6 inputs each. The pulse width would be around ...
0
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2answers
46 views

what is the real DC power dissipated by an inductor that is pulsed on off

A meter indicates a higher DC power being delivered to a circuit consisting of an inductor switched on and off by a MOSFET on both the high and low side, than the heat measured by a thermistor. The ...
1
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1answer
114 views

(schematic) Using a micro controller to drive Opto-coupler > 555 timer > MOSFET

I'm trying to use a micro-controller to activate an opto-coupler connected to 555 timer which is connected to a MOSFET. The circuit will drive a solenoid which draws 2amps at 12v. I'm new to circuit ...