Demystifying Switched Capacitor Circuits

Demystifying Switched-Capacitor Circuits

266

switches and four capacitors besides the op-amp. As before, C

1

and C

2

are the main

capacitors, while C

3

and C

4

are the auxiliary capacitors, and C

3

/C

4

= C

1

/C

2

.

This circuit can be considered the result of modifying the previous circuit (Figure

7.10). The modifi cation involves two changes. One is to merge the storage capacitor

C

3

into C

1

, and the other is to simplify the switching confi guration in the prediction

path. In addition to the area and power saved through the switch sharing and the

capacitor reduction, these changes give rise to a more aggressive compensation

(especially in the low frequen