Podcast #128: We chat with Kent C Dodds about why he loves React and discuss what life was like in the dark days before Git. Listen now.

Questions tagged [saturation]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
1
vote
2answers
365 views

Saturation in differential pair

I'm reading Analysis and Design of Analog Integrated Circuits by Gray & Meyer. In the differential pairs' chapter, there is this circuit and it says: Assume the collector resistors are small ...
-1
votes
1answer
382 views

how does a Avalanche photo diode[APD] recovery time depend on TIA

in one my of low light pulse detection project i want to sense a very low light of 1mW/m2 so for this kind of scenario an APD is a device with its internal gain can give me abundant current to detect ...
7
votes
2answers
961 views

Why does a C4467 transistor turn off slowly when collector-emitter current is low

I built the following circuit simulate this circuit – Schematic created using CircuitLab The clock has an amplitude of approx. 5 VDC. It's provided by a 555. I used two different values of R2 ...
0
votes
2answers
722 views

Unsaturated BJT

I'm struggling for an answer to part (c), I can do the first two questions. I know that \$i_C = \beta \times i_B\$, however, I don't know how to calculate the maximum current gain of the unsaturated ...
-1
votes
1answer
57 views

How was saturation current found? Was it assumed in this question?

I'm just a really confused about how Saturation current, Is, was either solved/derived or assumed?? Please see images of question and solution. The question requires that you find all the bias ...
0
votes
2answers
96 views

saturation point of electrical iron

In my work with electrical iron, I have done a lot of research to try to understand how to determine the quality of it. Is there a simple way to test for the saturation point? Some of the methods I ...
-1
votes
1answer
124 views

ngspice MOSFET region of operation

how to find region of operation of MOSFET in a circuit in ngspice? or how do you know that a MOSFET is in saturation in a circuit in ngspice?
1
vote
3answers
1k views

Photodiode in photovoltaic mode, overcoming saturation

can anyone explain to me why moving to configuration (b) overcame the problems I was having with the photodiode saturating? Many thanks, John
1
vote
2answers
6k views

How to find a saturation current for BJT from datasheet?

Saturation Current is one of parameters in Ebers Moll Model, but I can't find it in datasheets. I explore SC1627 and BC856 datasheets. How to find it? As opposed to How do I saturate an NPN ...
0
votes
2answers
548 views

What causes “positive feedback” in audio amplifier

I am currently using an audio amplifier to make a presentation. However, sometimes mid presentation the audio amplifier will go into a "positive feedback" mode where the sound coming out of the ...
1
vote
2answers
403 views

Why doesn't Class C modulator operate in saturation?

The following circuit is a class C (actually class B) amplifier used in AM modulator in my previous question. According to the textbooks, the transistor is driven into saturation in this class. A ...
0
votes
1answer
2k views

Output resistance of a BJT in saturation

It seems by the characteristic curve of a BJT, that it behaves as a resistance in saturation region. Is this conclusion true? and if so how can I calculate this resistance (seen from collector) from ...
1
vote
1answer
3k views

Analysis of Class C AM modulator

The following schematic is a class C AM modulator without use of any transformers I've just changed the parameters in spice to get a correct modulation. however I want to find the theoretical value ...
1
vote
1answer
855 views

decreasing base current on saturated npn transistor

I would like to know if decreasing the current at the base on a saturated transistor(as in the attached photo) will cause the transistor gain to increase and by that, to maintain the collector current....
3
votes
1answer
60 views

Is there any way to use the saturation harmonics to determine the rated voltage of a induction motor?

When the motor is running at no-load, the core eventually saturates as the AC supply voltage is increased. Therefore, harmonics will be present in the AC supply current waveform . I suspect that the ...
1
vote
1answer
209 views

Using a COTS common mode choke on DC

Are commercially available common-mode chokes, such as one you'd pull out of a dead switching supply, suitable for DC service up to their rated current, or will they saturate/do other baleful things ...
-1
votes
2answers
193 views

What is the effect of V(CE) to saturation?

I am following this tutorial about transistors. In the tutorial, it is stated that to be in the cutoff region, \$V_{BE}<0\$ and \$V_{BC}<0\$ must be true. The tutorial also states that however ...
1
vote
2answers
1k views

Newbie question - sawtooth signal generation - capacitor discharge via bjt

I'm trying to realize a sawtooth wave generator. The circuit is composed by an op-amp integrator which creates the ramp. Then the integrator output is chained to a comparator with a fixed threshold, ...
1
vote
2answers
367 views

Linear operating range of an amplifier as a function of frequency

How does the linear operating range of an amplifier (the linear part of the function that describes Power Out vs. Power In), both in theory and in practice, vary with frequency? In other words, if I ...
2
votes
1answer
944 views

How is reverse saturation current of a BJT measured empirically?

I'm not asking the definition, but wondering how do the manufacturers measure this parameter's quantity in a lab for instance? For example for Ic Vce characteristics they keep Ib constant and they ...
0
votes
1answer
445 views

Can an opamp be neither in linear region nor saturated?

I'm trying to build a voltage controlled DC current source. For this, I built this circuit: A little bit of context. The voltage supply is 5V. Current range must be from 0mA to 30mA or so. Load will ...
1
vote
4answers
2k views

Confusion in interpreting NPN transistor's saturation region

Above screen-shot is from a SPICE simulation of an NPN BJT where it shows the output characteristics Vce versus Ic. Ib is kept constant at 5uA where Vce increased from 0V to 5V. I'm having difficulty ...
1
vote
1answer
1k views

Forced beta too small

Let's take an example in which the recommended beta for a transistor's(NPN) saturation is 10.If you use a forced beta smaller than 10,will the transistor still be saturated succesfully?Can hFE be ...
2
votes
3answers
377 views

BJT Saturation with small load/ H-bridge

I am trying to analyze the operation of a BJT H-bridge configuration. I have searched through these forums and Google and can't seem to find an answer to my question. It is my understanding that it ...
1
vote
2answers
27 views

How to tell if a switching element is operating linearly?

For example, a p-mosfet in a buck or buck boost topology converter. Is it working optimally or inefficiently?
2
votes
1answer
412 views

Confusion with MC34063 Vsat

I'm currently designing an e-ink panel driver. My choice is MC34063 for generating required voltages and I want to use two of these for step-up and inverting converters. However I'm somewhat confused ...
1
vote
3answers
931 views

How is this BJT in saturation?

I simulated this circuit using Qucs: With Vin = 5V, VB = 0.746V and VC = 0.024V which means ...
1
vote
2answers
5k views

Saturation regions for BJTs and MOSFETs

After reading this post (3rd answer): (https://electronics.stackexchange.com/a/129423/54580) I almost got it why the saturation regions of BJTs and MOSFETs are in different regions of their diagrams....
2
votes
3answers
3k views

Push pull core saturation

I want to build a circuit similar to this one: I read that using push pull without per-pulse current limit or series with trafo cap can cause core to saturate because two pulses aren't perfectly ...
0
votes
2answers
6k views

Reverse saturation current of BJT?

This might be a basic question...but I'm having a hard time understanding reverse saturation current in collector-base junction in the active region(Is), Could anyone explain about it? Its temperature ...
0
votes
3answers
257 views

Understanding transistor circuits

I have been working my way through The Art of Electronics by Horowitz and Hill and I've just started the chapter on Transistors. I am having some difficulty in understanding this transistor circuit: ...
2
votes
1answer
86 views

Verify that an increase in 8º C will saturate a common emitter

In the Art of Electronics there is an assertion that if a bias is established with 0.5 the supply voltage, the transistor will saturate if the temperate goes up 8ºC. The schematic is the basic one for ...
1
vote
0answers
235 views

one-sided saturation with op-amp and RC high pass filter

I am working with a photodetecting circuit built as follow: When I drive an LED ON and OFF, I get the following waveforms: Blue indicates that the LED is turned on when a voltage is high and turned ...
0
votes
1answer
86 views

Current saturation

I have bought a bunch of 24v LED for the garden, during the first months all of them worked fine, but some after they burned out the power supply. The reason is because they were demanding high ...
0
votes
3answers
334 views

Transistor saturation

I am trying to saturate a transistor , a BC547 A , but I am having a hard time figuring out something.What hFE should I use to compute the base and collector current to make it turn on fully? Here is ...
-1
votes
1answer
55 views

Depletion NMOS that's saturated at 0V

May seem like a weird request for a part, but are there any Depletion NMOS out there that is already saturated when you apply 0V to gate or if the gate is not connected?
3
votes
1answer
4k views

Reverse saturation current in a BJT: active and reverse active modes

In (Sedra; Smith. Microelectronic Circuits), as well as in several other sources, the value of the reverse saturation current (\$I_S\$) is considered the same for the active mode and for the reverse ...
0
votes
1answer
70 views

Can the saturation of an OPA influence its input?

I am working with an analogue processing circuit, finishing with 2 non-inverting OPA one after the other. To characterise the noise produced by the circuit, I wanted to add a third non-inverting OPA ...
0
votes
2answers
573 views

calculate resistor value for transistor base

Below is a circuit where S1 is the output of a 555 IC timer (S1 switch for simplicity). I need to invert the output which I have done so in another project using the circuit below. Starting with ...
2
votes
2answers
559 views

Core saturation detector-differentiator

I am building some project that requires me to measure the saturation corrent of some homemade inductors winded on scavaged ferrite cores, so I decided to try and create a circuit that will aid me in ...
1
vote
1answer
232 views

NMOS saturation mode: why is there no channel?

I have a question about the saturation mode. The cross-section of an NMOS transistor in saturation mode is usually drawn like this: But it seems to me that there can be no current from source to ...
1
vote
2answers
1k views

Op Amp saturating below supply voltage?

I would like to know why op-amps saturate below their supply voltage. For instance I have a circuit with an LM358-N amplifier IC that is powered at +5 [V] and connected to ground on the other rail. ...
4
votes
1answer
2k views

Diy inductor saturation current

I have a boost converter that will convert 12V and 11A to around 20V and 6A. Since I didn't find any inductors (in my local stores) capable of such currents and frequencies and the correct inductance ...
0
votes
2answers
439 views

Would output signal affect input signal when the opamp is saturating?

I have learned that opamp would be saturating when the output signal is too large. My question is would the saturating output affect input signal, for example, change the amplitude of the input ...
1
vote
0answers
530 views

Passive harmonic filter: Why Immensely Hot and Humming

I encountered a passive harmonic filter, PHF with highly non linear loads, i.e. variable frequency drive, VFD (most of the time running 50Hz) serving an induction motor. I believe that it is a ...
3
votes
3answers
9k views

BJT - absolute maximum base current?

Let's look at the datasheet for an MMBT3904, just for example. The absolute maximum section talks mostly about maximum voltage differences, and a single current limit - the collector current. I'm ...
2
votes
1answer
196 views

Dual Op Amp should be saturating but it is instead tracking the negative pin input

I was attempting to implement figure Figure 34 on the AD734 datasheet in multisim (the national instruments SPICE simulator) Based off what I know of op amps, the output of U2b should be saturated to ...
1
vote
2answers
217 views

BJT in Saturation

Is it possible for the base current to exceed the collector current for a BJT in saturation mode? (If the base current was increased without the collector current increasing at all)
4
votes
3answers
155 views

What precisely is \$R_{ds(on)}\$?

I keep getting conflicting answers on this and it's absolutely killing me. Some say \$R_{ds(on)}\$ is the contact resistance in the FET (for instance, make many FETs of varying channel lengths, turn ...
8
votes
5answers
4k views

How to prevent op amp from saturating?

How can an op amp be prevented from going into saturation if the feedback is intermittently disconnected? For example, in this circuit (simplified case of a real-life problem), the op amp acts as a ...