### Welcome to EDAboard.com

#### yefj

##### Full Member level 5
Hello ,the general form of SAR ADC is as shown bellow in the formula but when i try to develop the 3 bit private expression for 3 bit as shown bellow:
i try
101 is 4C+C
But i cant see how $\frac{(N-X)}{N}=5/8$
N=2^3 X=3
X is Bits that set in a givern corevention
why in our private case X=3?
Thanks

#### yefj

##### Full Member level 5
Hello,we have a genral formula for the SAR ,
N=2^3-8
Why X=3 ? (bits that set in a given convertion)

#### sutapanaki

Maybe it is good to give a link to the thing you are reading so people can get the whole picture.

#### yefj

##### Full Member level 5
Hello,The genaral formula on slide 18 of the attached leacture
i am tryong to understand why th provate case in slide 14 means X=3?
Thanks

#### Attachments

• 1.2 MB Views: 5

#### yefj

##### Full Member level 5
Hello,In the formula shown bellow why the charge between V+ and GND is minus to the charge of Vref and V+ ?
Thanks.