Re: AD/DA design
Hi,
In pipeline ADCs, you can use transmission gates (it is said that they could reach to 15 bits resolution). You should minimize the on-resistance of the switch to minimize the ditortion it causes. But for the input switches especially if you have a sample and hold at the input, you'd better use bootstrap switches in order not to degrade the ADC THD.
The gain of the opamps are defined according to the resolution of the remaining sub-ADC.
The capacitor values are defined according to two main restrictions: noise and mismatch. You should calculate with both methods and choose the bigger one.
In order to have an optimum power dissipation, you can scale the capacitors of the stages, so that you would use smaller capacitors for the last stages.
You should consider a specific error for each of the limited gain of the opamps, the capacitor mismatch and the settling error of the opamps.