need help to design boost converter

[niks]

hi
im designing boost converter Vin = 2.7 and Vout = 45 V with Piezo cap. as load. Just now the efficiency is around 45-50 %. I also tried to use dynamic PWM, but i found that its also not much of use. timebeing im using 1mH inductor with DC resi. 2-3 ohm. and N channel FET controlled by PWM.
in this design im very particular about power consumption. just now inductor current is 150mA and piezo takes 3.2ms to reach 45V at 17.5KHz.
how can i improve the efficiency ???
thanx and regards
~niks~

 

[gabby]

Hi

First for change the signal from 2.7 to 45 the best way is to use a transformer(all the energy move to the second size).

second you have also complete some kind of buzzer
(that called dc buzzer) that have inside also all the interface and can work
also in 2.7v ,but see the power/freq out signal if is good for you if not
goto the first option.


also see supplier buzzer sites they give for you also app for build.

Best regards. 8)

 

[niks]

i cant use the transformer.its the design contraint.for me area and power consumption both are critical factors.so can u suggest any other alternative.
regards
~niks~

 

[gabby]

Hi

I think i have a small understand ??
when you say boost converter you mean to dc-dc converter supplier?
or
when you say Piezo cap you mean to audio buzzer?

If you are looking for design a dc-dc converter:
you have few comp that make them:

www.maxim-ic.com
www.linear.com
www.micrel.com
www.nsc.com
www.vishay.com

the eff that you can find from 2.7v to 45v in low current i think is ~75%
on the converters (maby is avaliable also 91%-97% )


If you are look for buzzer take one more small then 45v.

Best regards. 8)