I would like to build a 6 bit flash ADC using comparator

[barath_87]

Flash ADC design...

Hi,

I have designed comparator for pipelined adc , I would like to build a 6 bit flash ADC using that comparator.So please give some suggestions and materials regarding ....

Thank you in advance.

 

[mickey_melomane]

Flash ADC design...

Use 2^6 comparators with different Vrefs... Generate Vrefs using stacked MOS diodes, (Take care that ur current consumption is well under control...

The output of all your comparators together forms the "thermometer code output"...

Make sure all your comparators have same rise times, so that your output bits appear together...

Sidharth

 

[barath_87]

Re: Flash ADC design...

Use 2^6 comparators with different Vrefs... Generate Vrefs using stacked MOS diodes, (Take care that ur current consumption is well under control...

The output of all your comparators together forms the "thermometer code output"...

Make sure all your comparators have same rise times, so that your output bits appear together...

Sidharth

Thank you but I am stuck up in the thermometer code output to binary conversion can you pls help me in that part....

 

[fly6987]

Flash ADC design...

The book "CMOS Integrated Analog-to-Digital and Digital-to-Analog Converters by Rudy J. van de Plassche" is very good!

You can find all the answers in it!

 

[naalald]

Re: Flash ADC design...

Hi,
First, try simulink simulation of the ADC. That halps you a lot.

 

[rfsystem]

Re: Flash ADC design...

Be careful!!!


Its not 2^6 but either 2^6-1 or 2^6+1 comparators. The second solution gives you a overflow and underflow too.

 

[muralicrl]

Re: Flash ADC design...

Hi,

Kindly see the attachment, it may be useful to you,

If you need more details, don't hesitate to contact me.

Regards,

N.Muralidhara
CRL-BEL