Questions tagged [nmos]
A n-channel metal-oxide semiconductor (nMOS) transistor has n-type carriers in the channel. A positive voltage on the gate turns inverts the substrate (PWell) creating the channel and turning the device on. The term may also be used to describe logic circuits built around nMOS transistors.
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Will this over-voltage protection circuit work?
I am designing a PCBA that is powered from an AC adapter supplying + 19 VDC to the circuit. I want to add a protection against over-voltage, let's say up until + 24 VDC. I came up with the following ...
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Voltage drop in NMOS inverter with enhancement load
In the enhancement load NMOS inverter, why is the voltage drop across M2 at least equal to Vth when VIN is low ?
Is it because for M2 when VIN is low the voltages VGS = VDS, so VDS > VGS - Vth and ...
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Analyzing \$g_m\$ vs \$V_{in}\$ for a common source config
I had this doubt while going through the book "Design of Analog CMOS Integrated Circuits" by B. Razavi, if we are to plot \$g_m\$ vs \$V_{in}\$ for the above circuit, then we have \$g_m\$ =0 ...
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How do you justify energy band bending in an unbiased MOS Capacitor?
Here is a MOS Capacitor:
(Image source: Chapter 5 of Modern Semiconductor Devices for Integrated Circuits by Dr. Chenming Hu)
Now lets consider the idea that the gate voltage is held at 0V, just like ...
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Why simulation of single NMOS/PMOS on LTspice has big difference with manual calculation using Level 1 Standard Parameters?
I am researching the mode of operation on PMOS and NMOS using Level 1 standard parameters.
This is the information of the NMOS circuit to be designed.
Using transistor model level 1 parameters, ...
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How to interpret MOSFET connections and voltages
I have a few simple question about MOSFETs on how to interpret their symbols and how the pins and gate voltage are defined.
• I see symbols with the Source shown on the top and Drain on the bottom, ...
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How to determine rise and fall times of MOSFET
Rise and fall times of a PWM switching MOSFET must be paid attention because too slow switching times will decrease the efficiency and too fast will cause ringing. I want to know how to choose a rise ...
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Transistor failure in multi channel high frequency AC signals
[Intro]
To begin with, I am an undergraduate electrical engineering student working on my senior project. I wanted to make a wireless charging pad like that of Tesla's wireless charging platform and ...
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Driving NMOS source with a separate power supply
I am trying to see whether I can turn on 28 V voltage rail from a 5 V input signal using an N-channel MOSFET (NMOS). I am using IRF530N for now which has a threshold voltage of 4 V. I just modeled it ...
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Will my gate driver work for this situation?
This is my own design, I did a gate driver for the MOSFET. Would this design work, or should I instead use a gate driver IC?
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A simple NMOS circuit simulation. Is there a way I can use KCL to find Id instead of doing Id equation?
I know the traditional way to solve this, you find Vgs then you try to find Id.
But for this circuit, we already can figure out the current flowing through the 2K and 3K by doing KVL(assuming I1). Is ...
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is Vov of a nMos always VGS - Vt?
Looking at this graph from Analog Circuit Design Discrete and Integrated by Sergio Franco, is it always true that Vov = VGS - Vt? or is this only true at pinchoff point?
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Reconciling High Drain Voltage with Typical V_BE Drop in nMOS+PNP IGBT Configuration
I'm examining two design methodologies for IGBTs (Insulated Gate Bipolar Transistors) and have encountered a puzzling issue regarding the drain voltage in the nMOS part of an nMOS+PNP IGBT ...
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Multism simulation for NMOS type circuit, why I am not getting the expected graph?
I am trying to simulate my circuit for one of the question problems. The question looks like this
I have written a MATLAB script to see the expected graph
...
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Why is this LDO circuit not working?
I am trying to generate 5 V with this circuit for a load of 100 mA with a 2% tolerance in the output voltage. I don't want to use LDO ICs due to various reasons.
My intention here is to enable/disable ...
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What is the difference between an N-MOS FET and a tri-state buffer? [closed]
Is an N-MOS FET an equivalent of a tri-state buffer, where the source is the input, the gate is the enable, and the drain is the output?
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Finding the mode of a MOSFET
I'm trying to determine the state of MOSFET \$T_1\$ in the following circuit:
We are given that the threshold voltage \$V_\mathrm{T}\$ is \$1.5\ \mathrm{V}\$ and that every voltage source is \$5\ \...
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CMOS (Energy Supply of voltage) [closed]
Can someone please explain why, when \$ln\$ is transitioning from low to high, the energy supplied is \$C_{vdd}\cdot V_{dd}^2\$?
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PMOS configured in common gate
This is an NMOS configured in common gate:
I am trying to understand what a PMOS configured in common gate would look like. Would Vin and Vout be reversed in this case? So, would VDD be connected to ...
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How is the total gate charge of a MOSFET affected by the temperature?
For P- and N-MOSFETs, Vgsth will decrease (in absolute value) when the temperature rises.
What is the impact of the temperature on the total gate charge for P- and N-MOSFETs?
What is the order of ...
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Is there a common N channel MOSFET with Pin1: Gate, Pin2: Drain and Pin3: Source?
I have designed a circuit in which I have used a BSS138 N channel MOSFET as a switch to turn on a 12V 50mA load from a GPIO.
During the schematic design in KiCad, I have chosen the wrong symbol.
These ...
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How to make a power switch using MOSFETs?
I am stumped on trying to create a circuit that, through an enable of 3.3V will let +18V go to the load or prevent it from doing so. This is my current approach. I know the pullup resistor should not ...
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How can I take parameters from power NMOS and power PMOS transistors and translate these into LTspice simulations?
I am trying to simulate NMOS and PMOS power transistors in LTspice, but I keep getting error messages about the NMOS being duplicate.
Some of the earlier LTspice file is here. I am trying to have a ...
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Is it always given that ground has lower resistance than output even If output is far closer in an inverting nmos? [closed]
Currently I'm learning about MOSFETs (N-MOS and P-MOS) --basically how a transistor works. My question is why does the current always prefer the grounding output even though it is further away than ...
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Inverting MOSFET drive circuit, is my scheme correct? [duplicate]
I am an automotive engineer student, building an inverting MOSFET driver (where a MOSFET drives and controls another MOSFET, Vin low -> Main MOSFET closed, Vin high -> Main MOSFET open).
My ...
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Alternative to MOSFET transistors as a switch
I am looking for a 3-legged component that can be used as a switch as an alternative to an NMOS transistor. My circuit currently looks the following: -
simulate this circuit – Schematic created ...
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Bootstrapping circuit vs. charge pump for high side switching
I am designing a circuit where I need to do some high side switching to turn on/off the power to a circuit (part of some protection circuitry). This switching is actually very slow and only occurs ...
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Channel Length Modulation in mos
The follwoing is a screenshot from youtube.
According to the model on the left, it's easy to get
$$I_{DS} = I_{DSAT} + \frac{V_{DS}} {\frac{1} {\lambda I_{DSAT}}}
= I_{DSAT} + \lambda I_{DSAT} V_{DS} ...
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Io of NMOS in small signal analysis
The question is almost 7 years old and a few people seemed to be interested in this question. But the person who had posted the question said it's from textbook. I have doubt whether \$I_o\$ it's ...
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How to make fast CV/CC transition in linear NMOS regulator?
I want to design a linear regulator based on NMOS with CC/CV capability. I made a circuit with two separate loops (CC and CV), each of which is stable. The problem is in the transition moment when the ...
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