0
\$\begingroup\$

I'm using this Mitsubishi RF amplifer in a portable device. The Mitsubishi amp operates well between 7V - 9V.

But I have to interface with a power source that gives 1.5V, and stepping 1.5V up to 7V seems like a huge waste.

Are there any RF amps for a 400 MHz signal that operate closer to 1.5V? Or are there any super efficient step up regulators?

\$\endgroup\$
2
\$\begingroup\$

You wont find any 5W RF PA's running at low voltage let alone ultra LV like 1.5V. So you need a Step-up converter. Lots to choose from. 90% but not at 1.5V.. Look harder for a higher supply voltage.

Added:

Is this from a single D cell? I need to know the ESR of the 1.5V sources. i.e. the regulation of the voltage with current delta V / delta I.. This is essential.

Also will you have enough power to drive 6W step up converter that can deliver 5W.

http://www.maxim-ic.com/datasheet/index.mvp/id/1254 This is 90% efficient , and will deliver 1 Amp in the range 7~9V so exceeds your requirements. Cost It also has dual output capability.

| improve this answer | |
\$\endgroup\$
  • \$\begingroup\$ I bet you have NOT found an efficient 7V 7W up converter yet. some work at lower Voltage and corresponding power levels. WHat is needed? Good Ruck. \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Apr 20 '12 at 2:37
0
\$\begingroup\$

I assume you used this part because you needed 7 W output. There are all sorts of regulations you need to meet for transmitting at that power. Given your question, I don't think you are up to meeting those requirements.

It's not a huge waste of power to do the step-up. A 7 V requirement isn't unusual for a 7 W amplifier. But for 7 W and 40% efficiency you will need 17.5 W in. It just will be higher current if you start from a lower voltage. It shouldn't be hard to find a switcher that is 80% efficient to go from 1.5 V to 7 V.

| improve this answer | |
\$\endgroup\$
0
\$\begingroup\$

DC to DC step-up converters can be found here: http://para.maxim-ic.com/en/search.mvp?fam=stepup&tree=powersupplies

| improve this answer | |
\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.