Questions tagged [transistors]
A transistor is a semiconductor device that can amplify signals and switch power. The types that are used most are BJT (Bipolar Junction Transistor), UJT (Unijunction Transistor), and MOSFET (FET, for Field Effect Transistor).
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Phase shift near saturation mitigation in input stage amplifier -- How does this work, why does this work?
I'm trying to understand how this circuit works on the input stage to the 4192A Impedance Analyzer.
Apologies for the quality... this is the best scan I could find. The design is furnished with the ...
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Why does output of this reverse bias noise source not have normal distribution?
I am trying to build a noise source based on reverse biased PN junction (i am trying to replicate this project https://altusmetrum.org/ChaosKey/ ). At this point i tried multiple iterations but so far ...
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Arduino - Using NPN transistor as a switch to pull-up/down analog pin
Let me start by saying that I am not an EE, and my knowledge in Electronics is basic, so please bear with me and be patient if, initially I am bending a few rules.
In Epee fencing, a touch is awarded ...
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Is there any reference to design a 4*4 bit ram only using transistors
I'm currently doing a project and would like some help. I need to create a 4-bit 4-word RAM using PSPICE. (I'm both new to the PSPICE program and new to the topic of RAM)
I currently have successfully ...
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GaN Vs IGBT performances
I was making some research on GaN and I do not understand why GaN is so reveolutionnary. When I take a look on the following specification RdsOn and Coss (Cds + Cgd), the GaN semiconductor has lower ...
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Piezo Buzzer Driver Circuit
I haven’t used a buzzer before so I have tried to find out as much I could and finally, I am here to clear my few doubts:
Few details about my application:
Buzzer: AST1240MLTRQ (i was not allowed to ...
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What is the easiest way to change the polarity of a transistor based simple amplifier?
I would like to amplify signals from a silicon photomultiplier, which is an array of many small avalanche photodiodes (APDs). When one or a few APDs get hit by a photon, a small current will flow ...
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Transistor Ic vs Vce Curve Trace for one 2N3906 Shows Weird Scope Display Not Sure Why
I recently built a transistor curve tracer on a breadboard with my Oscilloscope and Arbitrary Waveform Generator. Most BJT Si transistors (NPN and PNP) show typical/normal traces but one device under ...
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Need help in selection of FET for transfer gate
I was studying the variable potentiometer X9C10x series. They are using a series of fixed resistors and some FETs to select points in this series branch. I need one variable point in my circuit. Can ...
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Identifying exact type of transistor
I can not identify the exact model of this transistor.
It reacts as a bipolar NPN Si transistor with EBC pin configuration (first image left to right,) not ECB! This seems to be made by Siemens. ...
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Gain of single input differential amplifier
When performing the small signal analysis of the circuit shown below, with \$ V_{1} = V_{in} \$ and \$ V_{2} = 0 \$, and output taken from \$ V_{02}\$, I consider the small signal model for half of ...
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Calculating the gain of a specific transistor amplifier circuit
NOTE: There is an error in the drawing above — C1 should be connected to the emitter, not the collector.
Hi Electronics SE, hope this is the right place to ask this, if not I'll gladly take it ...
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Comparing sine wave and triangular for spwm using comparator
i am trying to generate sinusoidal PWM by comparing sine and triangular wave.
First i just tried to compare sine wave with reference voltage in order to check the working of op-amp. I get a problem ...
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Alternate uses for Gate Driver - Driving a Load without External IGBT or FET
What issues would one encounter by using a gate driver IC to directly drive a load instead of using it to drive transistors?
For consideration would be the very affordable Infineon 2EDN752x series ...
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How does the biasing work in a JFET based triangle to sinewave converter?
To those who haven't see this cool little circuit it employs the non-linearity and symmetry of the JEFET to clip a triangular signal to make it more sinusoidal
Can someone please explain to me how ...
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Switching IC via FTDI232 DTR and transistor
I am trying to switch an IC on/off via the DTR signal pin on an FTDI232 USB/TTL Serial converter.
Basically during the flashing of my ESP8266, I need to be able to power the IC off and then on again.
...
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Gate of a transistor and mosfet damaged
In my schematic, I found that the base of transistor Q7 (2n2222) was damaged. I tried to replace it with a BS170 MOSFET, and the same thing happened where the gate was damaged.
The microcontroller ...
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Turn on/off a LED using a D-FF and a transistor
I'm trying to control a LED using some microcontroller and I designed a circuit using a D-FF and a transistor to handle it. It looks like this:
So I can control when to turn it on or of by simply ...
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High power boost converter circuit issue
simulate this circuit – Schematic created using CircuitLab
I made a dc-dc booster converter circuit.
With a 3 mF capacitor, 48V can be boosted to 200V in 0.5 seconds.
But for some reason, ...
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How to make an integrated circuit diode?
I have a design that makes use of some diodes. For example, see the left figure below where I connect a diode at some node to cause the voltage at that node to saturate at a voltage given by \$V_D + ...
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Is there a name for this transistor configuration?
The transistor configuration found in the schematic below can be used as the input to an op-amp that can work with a common mode input at or above the high supply rail. For example this configuration ...
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Transistor impedance
According to LDMOS transistor AFT05MS031N datasheet at p. 13 " ZSource - Test circuit impedance measured from gate to ground" for 155 MHz is
Z = 4.31 + j.7.54
https://www.nxp.com/products/...
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Possible FET with SMD marking 2YJ33
I need to replace a SOT-23 SMD transistor with the marking 2YJ33 (image attached Q1 and Q2). Any idea what it could be?
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RHP pole of two stage OTA
I learnt that for any amplifier (with some capacitor) if we short/open the capacitor and the polarity of gain changes, it is a sign of RHP zero.
Now, while applying the same analysis I obsevred that ...
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Weird NPN transistor symbol with a box connecting all three pins?
I've come across this symbol in the datasheet (link below) of a transistor for a halogen "electronic transformer" that uses two in a half-bridge operating at about 35KHz. The datasheet ...
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Small signal output impedance for a circuit with bipolar transistor?
For the following circuit, I need to find the small-signal impedance looking into the collector of the transistor at terminal X, not taking the load resistance Z into account:
My attempt at a SSM is:
...
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Design of transistor amplifier for nanosecond signal (with NPN transistors)
For a project/learning experience I want to design/build an amplifier.
The signal I’m provided has an approximately 1ns pulse width (duty cycle of 1%) with a peak of 2.2V and a repetition frequencyof ...
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MOSFET gate substrate voltage
In a MOSFET the channel is formed between gate and the body it would sense to use gate body voltage to form the channel. Why is gate source voltage used to form the channel?
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Circuit that can support incandescent or LED bulbs
I have a project using an ESP8266 to control a lamp socket. In very simple terms the sketch switches the lamp socket on or off based on some conditions. The sketch works fine.
What I would like to be ...
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Can I work out Vs of a saturated transistor with just the resistance of the resistor and the bulb? What would happen if I decrease R?
I know that I_c will be approximately equal to I_e but given I do not have more information I don't think it is possible to work out the voltage of the source??
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Help Identifying SMD Transistor
What is this component?
The only markings on the component are 96 G and M1. The board silk screen designates it letter Q so I'm thinking it's a transistor?
Please advise
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Mounting Emitter ballast resistor close to the power transistor
I am helping one of my HAM radio friends to build a 25 A, 13.8 V linear reg power supply. As commonly done, I am using the parallel power transistors to deliver the current and to limit thermal ...
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Why aren't semiconductor wafers diced into triangles?
Semiconductor wafers are circular, and usually they are divided into squares or rectangles. However it's more efficient to pack triangles into circles than it is rectangles, so less wafer area would ...
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How do you derive the output impedance of this BJT stage?
I am given the following circuit (neglect Early effect):
And, I am asked to find the output impedance looking into where V_out is taken
By inspection, I can tell ...
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Optocoupler 4N25 cut and saturation for zero crossing detector circuit
This is my first time working with an optocoupler and I'm trying to find the right resistors for a zero crossing detector circuit that has a 4N25 optocoupler, but the values I've calculated are not ...
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Protecting unpowered op-amp, or how can I use 12V to switch 3.3V?
I'm designing a Eurorack synthesizer module which includes an MCU, DAC (TI DAC8565), and TL074 op-amp for scaling and buffering the DAC output.
In normal operation the module will operate from a +/-...
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2N2222 NPN Transistor, no current flowing through collector
I have a 2N2222 NPN Transistor wired up in the most basic common emitter setting (emitter grounded, base hooked up with a 1k resistor to 5V, collector connected to load and load connected to +12V). ...
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Source-Follower Large Signal Analysis as Level Shifter
I have a question about the MOS source-follower / common-drain stage. In particular, it's behaviour as a level shifter:
The book mentions the following:
I'm having some trouble figuring out how the ...
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Series variable resistance with NPN transistor
i'm trying to build a symple voltage controlled low pass filter and in the design they ask for a transconductance amplifier (which works as a series resistance in the R C pair for the passive low pass)...
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Beginner trying to resolve transistor issues
I have designed a basic transistor circuit with the EveryCircuit simulator.
The idea is that when the switch is open, one LED comes on and when the switch is closed the other LED lights up instead.
It ...
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What is the purpose of a power MOSFET in this voltage-peak detector?
I am trying to understand the use of the 3 different power MOSFETS described in this peak-detect circuit. The circuit was designed to measure the voltage peaks from a photomultiplier and the Arduino ...
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Reading 2N2222 BJT datasheet
I know this question was asked before, But couldn't understand properly the datasheet reading.
I would like to control water pump via ...
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How do you find rO when solving this differential amplifier?
gm could be determined using Jacoletto (40*Ic, where Ic was found while solving the bias point)?
Some of my attempts at solving the circuit
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How does this timer 555 and transistor circuit work?
Is this the way this circuit works ?
If vref = 5v on the pin #5, then Vthreshold = 5v, and Vtrigger = 2.5v
With Vthreshold = 5v, if voltage on pin #6 Vp6 > 5v, then Vp3 is Vo = 0
With Vtrigger = ...
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How to choose MOSFETS by using the datasheets infos?
I know all the theory behind the MOSFETs, how to calculate the Id current based on (W/L) and (Vgs-Vth) and etc. But, now that I need to project a real solution, I feel like all of this is kinda ...
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How to control motor (1.5 V at about 0.5 A) with Particle Photon using optocouplers and transistors?
I’m trying to control a motor that runs at 1.5v at ~0.5A using a Particle Photon. I’m powering the Photon over USB (for now, at least) and the motor with a AA battery. I’ve tried designs based off ...
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Looking for a consolidated datasheet for commonly used transitors
I found it challenging to look for individual transistor pdf datasheets with somehow different layout styles then extract common parameters. Is there any consolidated datasheet or table that lists the ...
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Are there errors in the description of this circuit?
Background
The circuit describes the operation of a variable voltage power supply. In the description below the circuit diagram there are errors. Read through the description and note down any errors....
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Does UJT work as amplifier?
I had got a question in job interview " Draw a circuit of common emitter amplifier using Non Bipolar Transistor."
As the question said Non Bipolar, so I assumed that it might be related to UJT. But ...
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How to estimate the voltage gain, Input impedance, current gain, power gain, and output impedance for the amplifier in the fig?
β of the BJT is 100 and from dc analysis it is found that the quiescent point is ICQ=4.12mA and VCE = 6.72V.
If the emitter resistor RE is subdivided into RE1=100 Ω and RE2=900 Ω, with bypass ...