Demystifying Switched Capacitor Circuits

Demystifying Switched-Capacitor Circuits

238

goes high, C

1

is discharged to the load through the Φ

21

switch. But the remaining

capacitors (C

2

and C

3

) are not discharged, hence their voltages are intact. Next, the

Φ

21

switch is turned off and the Φ

22

switch is turned on, and C

2

is discharged to the

load while C

1

and C

3

are not. Finally, Φ

23

is on and only C

3

is being discharged to

the load. We will now look into how this interleaving confi guration helps further

reduce output ripples.

Consider an (N − 1)-stage converter, if the Φ

21

, Φ

22

, Φ

23

, till Φ

2N

switches in Figure 6.6

are turned on simultaneously, then input/output voltage waveforms such a ...