Can the SAR ADC be designed for 40Msps and 12 bit?

[manissri]

REG SAR adc

can the sar adc be desiged for 40Msps and 12 bit.
if not then why .
as we can design the 12 bit 40msps pipeline adc easly but not sar adc .
please clarify my doubt.
regards

 

[zajbanlik]

Re: REG SAR adc

Well first if you want to design 40 Msps-12 Bits SAR ADC, you need 480 MHz takt. That means your comparator, and your DAC need to have 2.1ns response time totally. That is quite a problem.
Second you need to design "12 bit good" comparator (regarding offset) and 12 bit good DAC (regarding matching) which is also very big problem.

Pipeline ist because of it's structure less sensitive to component mismatch (comparator offset). And speed is also not the issue.

 

[stocol]

Re: REG SAR adc

for a 12 bit 40Msps sar adc ,precision conflicts with speed seriously.
piplined adc a wise choice