Flash ADC (Parallel ADC) and Half-Flash ADC Explained

In this video, the working of Flash (Parallel) type ADC and Half-Flash ADC is explained.
By watching this video, you will learn the following topics:
0:27 Flash ADC Working
7:07 Flash ADC Advantages and Disadvantages
8:26 Half-flash ADC working
The Flash ADC:
The Flash ADC (also known as parallel ADC) is fastest among all ADCs.
The Flash ADC consists of
1) High-speed Comparator
2) Resistive Voltage Divider Network
3) Encoder Circuit
In this video, the working of 3-bit Flash ADC is explained.
Advantages of Flash ADC:
It is fastest among all other ADCs and it is suitable for large bandwidth applications ( e.g Satellite Communication, High-Speed Data Acquisition for Oscilloscope, etc)
Disadvantages:
1) High Power Consumption
2) Large Die Size
3) High Cost
4) Limited Resolution
5) High Accuracy of the Components (Resistors and Comparators)
Half-Flash ADC:
In applications where low power consumption and small die area is main criteria (for the same resolution with relatively good conversion speed) then Half-Flash ADC can be used.
For N-bit Conversion, this Half-Flash ADC requires two (N/2) bit Flash ADC and one (N/2) bit DAC.
In this video, the working of 8-bit Half-flash ADC is explained.
The link to the other useful videos related to ADC and DAC:
1) Introduction to ADC and DAC
• Introduction to ADC an...
2) Dual Slope ADC
• Analog to Digital Conv...
3) R-2R ladder DAC
• R-2R Ladder DAC Explai...
4) Counter Type ADC
• Counter Type ADC Expla...
5) Tracking Type ADC
• Analog to Digital Conv...
6) Successive Approximation ADC
• Successive Approximati...
This video will be helpful to all the students of science and engineering in understanding the working of Flash ADC and Half-Flash ADC.
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[@ALLABOUTELECTRONICS]

The timestamps for the different topics covered in the video: 0:27 Flash ADC Working 7:07 Flash ADC Advantages and Disadvantages 8:26 Half-flash ADC working

[@poojashah6183]

Your efforts are commendable and the knowledge you share is priceless👌🏼

[@Shafayet01]

Thanks man. You helped finishing my pre-lab assignment

[@World_Theory]

Thanks! This gives me answers to all the questions on this subject that I had.

[@pascalkreis1524]

What an amazing video. It helped me a lot. Good grahics too. Well earned view and thumbs up :)

[@BananaLassi]

it saving my project. thanks

[@praveens9390]

Thank you so much! I might just clear one subject coz of you guys:)

[@World_Theory]

Something new occurred to me regarding your audio… The effect that I presume is clipping, may be caused by echo in the room your recording in, especially is the surfaces are mostly bare. If this is a problem, and you want to fix it, there are a lot of different ways. But a quick one would be to hang some kind of cloth on your walls. Although I have a hunch that filling a large mesh net with packing peanuts, or some other loose, light material, and attaching it to your ceiling would work pretty good. I don't know you opinion on this, so I'm sorry if I seem pushy or something. Just trying to help…

[@ruvalcabagonzalezgerardo6316]

Hermano, tus vídeos son excelentes Muchas gracias 👌🏻

[@sahil8380]

Superrr brooo well said..👌👌 keep gng on always with more useful content and more videoes..we always love ur videoes and also love u..😍😍😍😍😍😍

[@tavishishaw3782]

u helped me a lot for exam😄

[@sabrinagarciasosa7517]

thanks for the video, I really understand better this topic :)

[@samriddhisharma7095]

Thank you so much for this video

[@mayurshah9131]

Just Superb 👌👌

[@vijayakumarr3519]

Sir is ADC and DAC series over for gate syllabus ?

[@ALLABOUTELECTRONICS]

For gate perspective all the topics have been covered. But I am going to cover other ADCs like sigma- delta and pipeline ADC, and importance of performance parameters of the ADC. I think it will be useful in general to everyone one who are going to use ADC and DAC in some application.

[@arunasadeepa2795]

Sir , In the half flash adc ,can we get the first 4bits of the output by directly from the first ADC ?

[@ALLABOUTELECTRONICS]

Yes, that's exactly how we get the 4 MSBs of output. (As I have mentioned at 9:13)

[@arunasadeepa2795]

Ok sir thanks for the quick response ❤️

[@JagadishTejavath]

A flash ADC uses comparators with a settling time of 40ns and a 3 stage digital decoder made of gates possessing a delay of 2ns.Determine the conversion time of ADC ?

[@GauravGupta-pb8mk]

Thank you sir

[@kimothefungenuis]

7 comparators is pretty expensive though!

[@ALLABOUTELECTRONICS]

That is why flash ADCs are not cheap.

[@kimothefungenuis]

@@ALLABOUTELECTRONICS Is it the type we use for signal processing and control? because the delay caused by standard ADC's can distort a real time signal that needs to be processed right then and there because say a temperature signal is a sine wave, it could appear distorted when inputted this way due to the sequential part that varies depending on values.

[@pramodsb1944]

Hi sir, on what basis we should select vref , if my input signal is varying from 2v to 6v

[@ALLABOUTELECTRONICS]

Typically for ADC, the reference voltage is specified in the data sheet. ( like 3.3 v, 5V, 9V, 12V etc)In your case, you need a reference voltage more than 6V. For example, if ADC supports up to 9V, then you can use that voltage. But again that depends on the ADC.

[@mohithreddymalapati7127]

I have a doubt that for this encoder we need 8 inputs but from 7 comparators we are giving 7 inputs to encoder then what about 8th input.

[@uditgohil7547]

I'm not getting an output one of the comparator when applying the input voltage of 5volts. Instead of that I'm getting 10volts.

[@ALLABOUTELECTRONICS]

Would you please elaborate how you have connected the circuit?

[@kannanvlsi8213]

Good Job.. Superb....

[@Vanshmishra023]

How it is 1v after R divides by R + 7R

[@shubhamkathare3128]

Awesome explaination👌👌

[@hendriagustian7082]

For the second flash adc onwards it is rather difficult to change to digital (too small) , 8:37

[@uditgarg6508]

how no. of comparators is 2^n- 1? it should be 2^n only

[@ALLABOUTELECTRONICS]

Just look at the diagram of 3 bit flash ADC. It requires 7 comparators.

[@subhradeb4800]

Awesome

[@Devil-dn2ew]

Sir, What is sigma delta ADC! Is it another kind of ADC! I haven't found in our channel ALL ABOUT ELECTRONICS!!!

[@ALLABOUTELECTRONICS]

Yes it's another type of ADC. It is typically used where high resolution is required. ( But speed is not that important). Someday, will also cover that on the channel.

[@Devil-dn2ew]

@@ALLABOUTELECTRONICS okay Sir!! Thank you.

[@drsherifff]

Every ADC should pick flash and maybe ignite

[@bubbles12350]

In our they teach me 8-comparator and 7resister .sir

[@ALLABOUTELECTRONICS]

It is in fact, other way around. Imagine just 1-bit comparator. To compare the voltage, using a voltage divider, you need at least two resistor. That means for 1-bit, you need 1 comparator and 2 resistor. That is 2^1 -1 comparator and 2^1 resistor. The same is true for n-bit flash adc.

[@freedomisfood6966]

Very very 😊 🫂 🙏 😊 🫂 🙏 😊 🫂 🙏 thanks

[@shoaaamir2110]

Maza nahi aaya

[@xXCrashTXx-1]

easier to understand is this: flash adcs are meta and half flash adcs not, Kappa

[@mohithreddymalapati7127]

I have a doubt that for this encoder we need 8 inputs but from 7 comparators we are giving 7 inputs to encoder then what about 8th input.

[@mohithreddymalapati7127]

I have a doubt that for this encoder we need 8 inputs but from 7 comparators we are giving 7 inputs to encoder then what about 8th input.

[@ganeshjami9606]

Another one is ground