From 3.3V to 5V: charge pump or DC-DC converter?

[surianova]

from 3.3V to 5V

hi!

I have a power supply 3.3v. Need to boost up to 5v to drive a circuit for about 8 mA. Should i use the charge pump to boost or DC-DC converter (boost up converter) ? In term of size and external component, which one is better?

 

[IanP]

Re: from 3.3V to 5V

Charge-pump requires less external components, so in general circuit based on a charge-pump will be smaller ..
**broken link removed**
Regards,
IanP

 

[marshel]

from 3.3V to 5V

You can use charge pump. I know some of this kind of IC such as LTC3200 (Linear) REG710 (TI) and CP2128 (chiphomer)

 

[flushrat]

Re: from 3.3V to 5V

For a 8mA load current, maybe you will need external capacitors, unless you have a rather high frequency clock.
Let's consider a common dc-dc.
+ -------Reff------ +
|
V1 Iload V2
|
- ------------------- -

V1=2*3.3=6.6V V2=5V Reff=1/(f*C) (f is chock frequency of chargepump, C is boost cap)
and (V1-V2)=I/(f*C)
if f=100MHz, then C=50p, which will occupy a quite large on-chip area.

 

[hi_hedonist]

Re: from 3.3V to 5V

dc-dc conveter is also a good option