Electronics - Bipolar Junction Transistors (BJT) - Discussion


When transistors are used in digital circuits they usually operate in the:

[A]. active region
[B]. breakdown region
[C]. saturation and cutoff regions
[D]. linear region

Answer: Option C


No answer description available for this question.

Bhargava said: (Oct 31, 2010)  
Generally the digital circuits have two operating points 0 and 1. So when transistor operates in saturation region it can be switched on and off.

Priya said: (Nov 2, 2010)  
Saturation mens input voltage is max and out is minimum so it can consider as zero and in cutoff region input is zer hence max output. So can consider as 1.

Chenchureddy said: (Mar 3, 2011)  
Digital circuits operate 0 or 1 in binary form. So saturation and cut off regions can operate the circuit.

Arnab Bhattacharya said: (Apr 8, 2011)  
Generally Digital circuits require swithcing elements and that's why tarnsistors whenever used in digital circuits, always are operated in saturation (ON) and cut-off (OFF) mode.

Amit Kumar said: (May 26, 2011)  
Priya is right. I totally agree with her. Good.

Mahender said: (Jul 6, 2011)  
Digital circuits operates only in two modes ie saturation & cut off because it contains binary format 0 & 1 where it operates.

Anil said: (Jul 21, 2011)  
Priya is right. I also agree very Good.

Veerendra said: (Sep 3, 2011)  
I accept you, but you say about active region.

Xyz said: (Sep 9, 2011)  
Hey Mr.Veerendra Active region is the region of operation.

Tanisha said: (Oct 3, 2011)  
It should be active region.

R.Divya said: (Oct 25, 2011)  
Here saturation region means max range and cutoff region means minimum voltage. So in digital sys we are using 1 and 0 only.

Sukhpreet Klar said: (Jan 28, 2012)  
In saturation region transistor acts as closed switch and in cut off region it acts as open switch. In digital circuits o/p can be 0 or 1. So when in saturation region means closed switch it gives output 1 and in cut off region means open switch it gives o/p 0.

Sukhpreet said: (Jan 28, 2012)  
While transistor has to be used as an amplifier then it is operated in active region.

Santosh Singh said: (Feb 18, 2012)  
Saturation region of transistor is maxim. Current flows (collector base, emitter base current in forward direction, but collector current not constant with rapidly inc. Ck. This is resign behind that.

Jay said: (Feb 27, 2012)  
In digital cirucuit transistor are used as a switch.

Transistor used as a switch when they are either operate in the saturarion or in cutoff mode so answer is option c.

Thelip Kumar said: (Mar 1, 2012)  
For amplifying purpose we use transistor in active region and saturation or cutoff regions used in digital electronic circuits.

Rajkumar said: (Aug 10, 2012)  
Where these tranisitors are used in real time fields ?

Shakti Raj Chopra said: (Aug 14, 2012)  
Why we are discuss, I don't know.

Simply For amplifying purpose we use transistor in active region and saturation or cutoff regions used in digital electronic circuits.

Dileep Kumar said: (Aug 15, 2012)  
Basically the digital circuits operate only binory digits (i.e 0 and 1) , when ever this is opearates in bjt saturation region (the swith is on) , &the cut off region (the switch is off).

Praashant Yadav said: (Sep 14, 2012)  
Digital circuit requre swiching element (ON&OFF) , that why transistor whenever used in digital circuit always operate in saturation (ON) & cut off (off) in region.

Sukirti said: (Sep 25, 2012)  
Digital circuits always operates in two modes that is 1 & 0, and we can also say that though its a circuit so the transistor can be act as a switch, and switch always obtained in saturation and in cut-off modes. Active mode is used only for amplification factor.

Sulukumas said: (Oct 4, 2012)  
Should be in saturation and cut of region.

Vimal said: (Oct 18, 2012)  
In digital circuit We works with either HIGH or LOW, so when transistor is in saturation (Vce i.e. max) it is on high voltage, and low voltage when it is in Cutoff (0V).

Sayan Spc Burdwan Gangpur said: (Dec 25, 2012)  
As far I think that Digital circuit require switching element (ON&OFF) , that why transistor whenever used in digital circuit always operate in saturation (ON) & cut off (off) in region. Basically the digital circuits operate only binary digits (i.e. 0 and 1) , when ever this is operates in bjt saturation region (the switch is on) , &the cut off region (the switch is off).

Yogesh Kale said: (Jan 31, 2013)  
For switching purpose transistor are used in saturation and cutoff. Whereas for amplification purpose transistor are used in active region.

Jabez said: (Jun 28, 2013)  
Digital circuits used for switching purpose thats why transistor works only in saturation and cutoff region.

Omkar said: (Sep 19, 2013)  
But transistor is mostly used as an amplifier in active region of it.

Dheeraj said: (Oct 6, 2013)  
Anybody tell me what is the significance of cut off region?

Jhansi said: (Oct 28, 2013)  
Cut off (no collector current), useful for switch operation.

Zainab Jamal said: (Dec 25, 2013)  
What can we say about the voltages in cut off as well as saturation ? I mean when Ic is zero in cut off Vce should be maximum right?what about other voltages i.e. (base emitter and collector base) I know that base emitter junction will be reverse biased but can we come to know about the exact voltage? kindly guide me.

Zainab said: (Dec 25, 2013)  
I just want to know the voltages in both the modes i.e. cutoff and saturation.

Anubhav Chaturvedi said: (Jan 9, 2014)  
Digital system as very clear having two states namely high or low, saturation implies high state and cut off implies off state.

Purushotham.T said: (Mar 9, 2014)  
The whole digital world considers only two states. That is on and off/ 1 and 0. So now the transistors saturation and cut-offs can be considered as on and off respectively.

Amir Khan said: (Apr 6, 2014)  
Is transistor operates in saturation or active region itself (as the amplify or switching) or we do this?

Supriya said: (May 6, 2014)  
When transistor is used as an amplifier then it has to be operated in active region and when the transistor is use in a digital circuits then it can be operated in Cut off (open s/w means 0) or in saturation region (closed s/w means 1).

Munna Babu said: (Oct 19, 2014)  
In digital electronics world transistor is nothing but a switch, switch has two modes can be ON or OFF. To get the desired output you decide what you need it ON or OFF. Now we conventionally assume if ON is 1 then OFF is 0.

So saturation mode means your circuit is closed which also means your switch is ON which lead us to say our output is 1 and cutoff region is opposite. Common sense if you transistor in saturation mode output is max which is 1 however in cutoff it is opposite.

Key points : Saturation MEANS ON what is ON your switch also means circuit is closed. And cut OFF is OFF what is OFF your switch means circuit is open means 0 output.

Priytam Kr Singh said: (Nov 7, 2014)  
As we know that when we talk about digital circuit then one thing is very clearly understand the operation of the circuit is totally depend on logic 1 (i.e high voltage) or 0 (i.e. Low voltage) and we can say that saturation is logic 1 and cut off region is logic 0.

So no doubt when transistor are used in digital circuit they operate in saturation and cut off region only. Because it full fill the digital circuit requirement.

Sumanth Punda said: (Mar 29, 2015)  
Digital circuit means 0 or 1 therefore cutoff means 0 and saturation means 1, that's all.

Firoj Hosen said: (Sep 8, 2015)  
Saturation and cut off region.

Shivam Thakkar said: (Oct 12, 2016)  
What about active, breakdown and linear region?

Dipak said: (Jan 6, 2017)  
In which region, Analog circuit will work?

Dipak said: (Jan 6, 2017)  
In which region, Analog circuit will work?

Vijay said: (Jan 27, 2017)  
Yes I agree @Tanisha.

Prince Pandey said: (Sep 13, 2017)  
Generally we are using min and max term in digitial circuit like that the term will be 0 to 1 or others like that one is min and second one is max then the transister will be linear region and it also oprate in satutration region which help us the switch will be on and off.

Hussam Sarhan said: (May 10, 2019)  
Yes, I agree with this answer because the saturation and cut off mode are the most available for this question.

Anomie said: (May 30, 2019)  
The transistor is always work in digital as a switch on/off or close/open and 0/1 is similar as 0V(low) and 5V(high)so, saturation and cutoff regions is the answer for digital function.

Although transistor is work in the active region because it has a biased voltage 5V/15V so ip is forward biased and op is reversed biased when ip is apply >0.8V op is 5V(high) and ip is <0.7V op is 0.4V(low).

Anvesh Dangeti said: (Oct 29, 2020)  
One of the most common uses for transistors in an electronic circuit is as simple switches. In short, a transistor conducts current across the collector-emitter path only when a voltage is applied to the base. When no base voltage is present, the switch is off. When the base voltage is present, the switch is on.

The areas of operation for a transistor switch are known as the Saturation Region and the Cut-off Region. And use the transistor as a switch by driving it back and forth between its "fully-OFF" (cut-off) and "fully-ON" (saturation) regions.

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