How to drop from 6V to 5V a "clean" way?

[charudatt]

Hello Sougata,

I have a similar requirement, but without the LCD. Same 6V operation and a Piezo buzzer.

Its basically a code lock operating on 6V. A couple of flashing LED, Sounder (piezo) and a Solenoid.

I have a design before me which does not use even a series diode to drop the voltage, So I presume , the PIC can take that, till the Alkaline battery drops down to safer level on its own. Seeing this , I feel a series diode would be good.

I used a GP PNP transistor with zener at its base to regulate the voltage. Don't know if that's the right way.

Any help ?

[Ron Marcus]

Check the new TPS60002(xxx1 for 3.3 volts) from TI. It will take 2.5 to 5.5 volts input, and put out a regulated 5VDC up to 800 mA. It will allow you to wring every drop of juice out of four Alkalines. It's a tiny 3x3 package, but works like a champ.