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# nmos

• ## Current source load mosfetJuly 21

Guys I have a silly doubt. above is a standard circuit. I wish to ask how can a small signal current exist through the transistor shown above? The current source ( which is dc) will always force the saturation cureent of nmos to be = ID. So how can t

• ## Analysis of a Common Source MOSFET AmplifierFebruary 15

Here's a design question our prof gave us to study for the exam. I'm having trouble putting it together. The transistor has the the following properties: Kn: 1.4mA/V^2: Vtn = 0.2V; λ=0.01 V^-1; Cgs=5pf; Cgd=0.8pf A 5V peak-to-peak sine wave is seen a

• ## Biasing using constant current sourceFebruary 11

guys i was going through this diagram in my book when these lines came along(i am a student): Here RG(usually in M-ohm range) establishes a dc ground at the gate and presents a large resistance to input signal..... I want to ask why resistor is used?

• ## Voltages to keep my circuit running at 200mA with NMOSFETSFebruary 7

Im trying to build a circuit to send information using IR led, using pulse signals my leds (TSAL6400) operates at 1.35V, and their maximum pulse current is rated 200mA After struggling a bit with BJT transistors, and realizing that since I'll send th

• ## 3-pin MOSFET: P or N type?February 5

This may be a silly one but I couldn't seem to find an explicit answer: with a 3-pin MOSFET, how do I determine whether it's an NMOS or PMOS? I'm making some assumptions here: I've already found the Gate pin, which has no conduction to the other two

• ## microelecectronics doubt January 25

I was going through Sedra and Smith (6th edition) and had a doubt. In example 4.11 (page-405), how do we know in a question if we have to join G and S terminals and there will be a current flowing through Rg which is of 10MOhm. In the equivalent smal

• ## Multistage CMOS amplifier designJanuary 14

my professor gave us a task to design a multistage amplifier using NMOS and PMOS transistors with a minimum width W=18um, 1.8v battery(multiple if needed and any sort of resistor/capacitor. The only requirements are: Voltage amplification: A=10 Input

• ## Basic Nmos amplifier workingDecember 28

I am trying to understand this circuit here. I do not understand clearly how this works. I know that the PMOS is a current source but what impact does the resistor Rb have on this ? Could anyone help me out with its working ? --------------Solutions-

• ## Trying to simulate the linear region of a MOSFETDecember 6

I wanted to simulate the linear region, so I tried this: – Schematic created using CircuitLab I expected the triangle wave to be curved, but it didn't have those features. Am I doing something wrong or am I expecting the wrong results? How does one u

• ## Can a NMOS transistor be used as a Current Controlled Voltage Source?November 28

Assuming an NMOS transistor is in saturation. Can you apply a current \\$I_{DS}\\$, resulting in an output gate-source voltage (\\$V_{GS}\\$)? --------------Solutions------------- The gate is isolated so by itself it cannot generate a voltage. An NMOS on

• ## NMOS - Why is a resistor necessary?November 26

I understand how the logic levels of an NMOS work with a pull-up resistor. 1. What would happen though if there was no resistor attached? (What would the logic levels look like and why?) 2. What would happen if there was a pull down resistor instead?

• ## Depletion Mosfet working as enhancement NMOSNovember 23

The depletion mosfet can also operate in enhancement mode when the gate voltage is positive (say for depletion type NMOS). My question is : Will the Shockley equation be still valid in the enhancement mode? or Should we use the equations of enhanceme

• ## Bias common source diode connected loadNovember 17

To amplify small signal we need to bias M1 and M2 in saturation mode. Obviously, M2 is always in saturation because Vgd = 0. However, how should I bias M1 in saturation? --------------Solutions------------- In order to keep M1 in saturation, Vg - Vth

• ## Biasing an NMOS to get rid of \\$V_{th}\\$November 2

So here's a common way of cancelling out the \\$V_{th}\\$ in an NMOS. Am I better of use a good quality zener (in series with a resistor) or stick with voltage divider R1 and R2 below. Assuming we can have very low tolerances for R1 and R2 and we can c

• ## MOSFET shorted after I connect them in parallel, what's wrong?October 28

One of my MOSFET source-drain shorted after I connect them in parallel? So I was making an ARC speaker yesterday, and I used one MOSFET ( irf540), and it got really hot, but it did not blow up, so I decided to put another MOSFET connected in parallel

• ## SOT-23 NMOS transistor power dissipationOctober 9

I am working on a design of a control system that controls a few small solenoids, each drawing about 200 mA of current and operating at 15-18 V. These solenoids are activated by NMOS transistors. Due to the size constraint that I have for the PCB con

• ## Simple NMOS transistor circuit output impedanceOctober 6

I am having trouble figuring out the best way to determine the output impedance of this simple NMOS transistor circuit: Both transistors are equal, and the body effect is ignored. What method should I use to find the output impedance? Should I find t

• ## CMOS: Why is an nMOS transistor a bad conductor of high logic, but a good conductor of low?October 2

I can't find an answer that addresses this and makes sense to me. I know that V_t is subtracted from the 'output', but I don't understand why. --------------Solutions------------- It's all to do with gate voltages. A standard Enhancement Mode NMOS re

• ## Gate voltage and drain current relationSeptember 27

I am new to electronics and have the following doubt. Say Vgs= 3V to a NMOS produces Id= 3A. Now if we place a 3A current source at the drain,will it cause a 3V at the gate, when the gate is open (assume source is grounded) ? Why? Also what happens w

• ## High Drain Current MOSFET vs Low Drain Current MOSFET for Synchronous Buck ConverterSeptember 2

For a battery charging application, i have to build a synchronous buck converter (i/p voltage = 12V , o/p Voltage = 4.5V) which would be driven by a PWM signal from the micro-controller. This Buck converter's operating frequency would be around 62kHz