Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [linear-region]

15 questions
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Is the Rds(on) of a MOSFET typically specified at the boundary of the saturation and triode regions?

Datasheets specify the Rds(on) of a MOSFET at some specific gate-source voltage, e.g. 100mΩ @ Vgs=4V. Up until now, I assumed that the test gate-source voltage was essentially arbitrary and chosen depending on the intended application. However,…
Polynomial
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MOSFET in linear region

Can we work with a MOSFET only in the linear region? I want to use it as variable resistor so it can provide a fixed amount of current. The MOSFET SOA should not be violated.
sikhar
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MOSFET terminology seems to vary in every article I read

For someone trying to learn about FETs, it seems there is no consistency in terminology (unless I am reading things wrong.) I am trying to understand the FET as a switch (for power applications.) It has become clear that you want to operate a switch…
Hasman404
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How to conclude region of operation for a series combination of MOSFET

I understand that M1 is on and for M2 to be on the intermediate voltage(drain on M1 and source of M2) should be less than 1.5V. Also if M2 is ON then M2 is in saturation since Vds>(Vgs-Vt) for M2. Now coming down to M1 and applying the same…
Fawaz
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Why aren't these instrumentation amps working for linearly driving a generic MOSFET?

If you've read my previous posts, I would say now that I've pretty much given up on the idea of parallelizing op-amps. I've stumbled onto instrumentation op-amps and decided they were good enough for my purpose. So here I am trying out different…
Tempus Nomen
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Why is the collector region doped?

As long as within the active region the collector-emitter junction is reverse biased, is there a purpose for which the collector must be doped? Moreover, not only that it is doped, but it is moderately doped, thus more than slightly doped like the…
pauk
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FET DC operation in the ohmic region if the SOA curve doesn't have a DC line?

From my understanding, the SOA lists the drain current for a given VDS in the ohmic and saturation regions where the FET can function without damage. I read a thread that says FET SOA graphs with short pulses and no line for DC operation are not…
AllHailTheMilkman
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MOSFET operating point in linear mode

I have this question, where the drain-source current and its bias gate voltage of a MOSFET is known where source is connected to ground. I find its drain current is less than saturation current by a huge margin, but not zero. So I have concluded…
Sairam Madadi
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Current Mirror Circuit

Below is a sample current mirror circuit. I understand that If the transistor Q1 is connected in a diode connected BJT configuration and the Transistor Q1 and Q2 have identical transistor parameters, The current flowing through both the transistors…
user220456
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Linearity in Differential Amplifier

Trying to understand what is the maximum and minimum for the input signal of a differential pair by solving this example below. My solution: To let the circuit operate as a differential pair, it must be in an active region where $$ VCE>…
chami
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Operating of FET in linear region

I have some data and would need some help to design a schematic. My target is to deal with the inrush current. I have a supply voltage range of 25-42V. A capacitive load of 1500uf. So I would like to charge this capacitor with a max 1A current in…
sikhar
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Transistor - Saturation and Active Regions

I am using this BC817-40 transistor as a switch. In the above image, we can see that inorder to operate my transistor in the saturation region, I need to make sure my Ic/Ib ratio is less than 40. And to make sure it is in the active/linear region,…
user220456
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MOSFET regions of operation

Let's say I have a MOSFET already operating in saturation such that Vds > Vgs - Vth. Can I make it to operate in triode or linear region by simply varying the drain voltage such that now Vds < (Vgs - Vth) where Vth is the threshold voltage for…
Ashok Chakri
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CCD sensor: Digital Counts vs Exposure plot vs Dark Digital Counts

First, my question concerns an individual pixel/sensor from a CCD array of a digital camera. From my understanding, the Digital Counts is linear with Exposure time. However, this line will be different for different light sources. My intuition led…
user3731622
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Finding MOSFETs with greatest linear region

I want to make a cheap variable gain amplifier using an op-amp, using a MOSFET as the variable resistance. The circuit is for an audio application at line (signal) levels (ballpark of 1v peak to peak). I need help in finding a suitable MOSFET. At…
Jodes
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