Digital Electronics - Digital Concepts - Discussion


The range of voltages between VL(max) and VH(min) are ________.

[A]. unknown
[B]. unnecessary
[C]. unacceptable
[D]. between 2 V and 5 V

Answer: Option C


No answer description available for this question.

Sree said: (Dec 20, 2010)  
I think they are necessary because for any circuit we need to know their limits.

Mahesh said: (Feb 2, 2011)  
Unacceptable is right ans.

Mohamed said: (Mar 30, 2011)  
Ya it depends on the emitter and source voltage.

Sushma said: (Apr 30, 2011)  
So? why is it unnacceptable?

Deepika G said: (May 4, 2011)  
My question is sme as shushma's question, why it is unacceptable?

Deepak said: (Jul 2, 2011)  
Same as sushma.

Jigar said: (Jul 14, 2011)  
It is unacceptable in some sense like the components are made by various manufacturers so if we fixed minnimum Vl then the component made by one manufactrer may work on tht voltage but on the same voltage, component made by another manufactere may not work on tht voltage. So my mean to say is the voltage values may varies depending on manufacterers datasheet.

Karthik said: (Sep 5, 2011)  
Exactly as jigar said IC's vary from manufacture to manufacture.

And the values of VL and VH vary.

Kalpana said: (Sep 9, 2011)  
Thank you karthik.

Kishore said: (Nov 2, 2011)  
The range of voltages between VL(max) and VH(min) are unacceptable because in digital system VL(max) is taken as 1 and VH(min) is taken as 0. Other valtages in between are not accepted in the digital system.

Niranjan said: (Nov 16, 2011)  
But in digital systems 0 to 1.5V is treated as logic 0 & 3.5V to 5V treated as logic 1.

So that why it is unacceptable.

Sss said: (Jan 12, 2012)  
I think it is not unexpectable. We need to know every component voltage range.

S.prem Kumar said: (Mar 11, 2012)  
As karthik said, vl and vh values vary from manufacturer to manufacturer. Because, one manufacturer may design for one volategs but on that same voltages, no other manufacturer component doesn't work. So, it is unacceptable.

Poonam said: (Apr 4, 2012)  
Am also agree with niranjan because in digital voltage in b/w 1. 5v to 3. 5v is unvaluable thats why it is unacceptable.

Kaushal Kishor Rai said: (Dec 19, 2012)  
Voltage between vl and vh is not acceptable because the IC property is vary from one manufacturer to other.

Gaurav said: (May 16, 2013)  
Digital devices works on 0 and 1 only. i.e. for 0, the voltage range is VLmin-VLmax and for 1, its VHmin-VHmax. So, the gap between VLmax and VHmin means nothing to a digital system because its neither 0 nor 1. Its just a transition state.

That's why, this region is unacceptable for digital devices.

This question is from digital point of view, not from analog.

Unknown said: (Jun 9, 2013)  
Which voltage they are talking about?

Murugan said: (Jun 21, 2013)  
@Kishore is right answer, in digital electronics logic 0 and logic 1 are the two states, there is none others. Some students said 1.5 is treated as 0 and 3.5 is treated as 1, but even though the voltage is 3.5, then why you are taken it as 1 or 5v because it is unacceptable in digital electronics.

Regine said: (Jul 20, 2013)  
How many voltage that can take in?

Mohit Pathak said: (Aug 8, 2013)  
Normally looking at the options. Option A is not ok because voltages are known and can be measured. Option B Is not ok because all measurable quantity has it's significance. Option D cannot be because we observe less than 2 volt while measuring and 1.5 we do work as low limit. So, would like to go for Option C, because we always go for 0 and 1 in digital electronics so min and max limit are unacceptable.

Rahul said: (Sep 24, 2013)  
Generally In digital logic design there are voltage and current parameters defined so regarding to these parameters it is described that the voltage range between the Vlmax and VHmin in unacceptable i.e it is neither 1 nor 0.

Sai Krishna Kasam said: (Dec 16, 2013)  
It won't make sense if set max and min voltages without knowing circuit components so acceptable.

Pooja said: (Dec 21, 2013)  
There is something called strong 0 and weak 1. Could that be related here, because a voltage near to 5V say 4.8V is treated as strong 1.

Shrenika said: (Aug 17, 2014)  
Why it is unacceptable?

Rudrasen Pal said: (Sep 28, 2014)  
I think in digital by quantization.

We make that level of supply according to our device.

Generally its 0/5 volt.

Parul said: (Nov 5, 2014)  
My question is if value vary from manufacture then its value should be unknown, why it is not acceptable? If in any IC value matches then what?

ARIF said: (Jul 23, 2015)  
It is unacceptable because of emitter current is zero.

BHARGAV said: (Aug 30, 2015)  
I think that the values are not necessary as the circuit operates for either max or min with acceptable errors.

Nitesh said: (Sep 29, 2015)  
I think it related to Noise Margin. So analyse the question right to noise margin.

Srilu said: (Mar 15, 2016)  
Why can't it is unknown.

Kiran said: (Jul 30, 2016)  
Digital circuits are mainly for "low power applications".

So, as Jigar said manufacturer have a requirement to make an IC in which 1-means a high voltage level (Vdd) similarly 0 for low voltage (some. X). That Vdd and x depends on requirement and transistor technology in which IC is manufacturing (channel length).

So the answer is C.

Naina Pathak said: (Sep 20, 2017)  
Answer is C.

Vaidehi said: (Apr 13, 2018)  
Since it is digital that's why no varying value is acceptable thus answer is unacceptable for digital circuits.

Priyanka said: (Oct 18, 2018)  
I can't understand. Please explain it briefly.

Kurdapi said: (Sep 16, 2019)  
I think the right answer should be C. Agree with the given answer.

Prashanth said: (Jul 27, 2020)  
It's not about real voltages. In an ideal world, Digital circuits will have one single high voltage for 1 and another single low voltage for 0. All others are not allowed. Two voltage levels for two symbols. However this is not possible due to noise and hence we consider small ranges for both. So, ideally option C is correct.

Anubhav said: (Dec 26, 2021)  
In this world of semiconductor, anything above VL (max) and below VH (min) is unacceptable, because that is called state of uncertainty.

It has to do with noise margins and fabrication defects. VL (max) is acceptable noise margin for low state, VH (min) is acceptable noise margin for high state.

Actual voltages may differ from implementations to designs and fabrication methods.

Syed Shakeeb said: (Apr 7, 2022)  
0 to 1.5 logic 0.
1.5 to 3.5 is unacceptable.
3.5 to 5 logic 1.

If the value of voltages lies between 2 to 3 is known as unacceptable.

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