Effective bit question

[yefj]

Hello, the first stage output is 2Vin-Vdac,the second stage is 2(Vin-Vdac)
I know that in order to calculate the effective bit we do Log2(x) calculation.
Why in the first stage we put x=2 and the second we put X=3
why the first one is called one bit. and the second one is 1.5 bit?
Thanks.

 

[Puppet123]

Read this: https://www.maximintegrated.com/en/...~:text=A 1.5-bit flash ADC,on the VRESIDUE vs.