How to convert 3.6v to Transducer excitation 21 volts

[suncq]

I have a project about battery powered telemetry unit now. Battery is 3.6 voltage. I need to convert this voltage to Transducer excitation 21 volts (@ 200mA).Because It will be into ADC channel. the ripple voltage need be as little as possible.
any tip? thanks in advance!
suncq@126.com

 

[blueroomelectronics]

200ma at 21volts will require more than 1.4A from the 3.6V battery since any voltage multiplier will not be 100% efficient. Better have some pretty hefty batteries.

 

[suncq]

thanks for reply!
But I need to provide the Transducer excitation just 2 senconds at 21 volts. I use a 3.5v(14.5AH) battery.

Added after 6 minutes:

you could see the url
**broken link removed**

But I don't kown how they do?

 

[blueroomelectronics]

National Semiconductor make boost ICs. Make sure it's rated for at least 2Amps
Usually it's an IC, powerfet, diode & Inductor.

 

[Computerman29]

Greetings,

Try this chip:

**broken link removed**