Hi there everyone, I have a quick question regarding using an mc34063 and external pass transistor in a design of mine.
Basically, the design is a portable unit, running off of a single 3.7v lithium cell. My intention is to have the ability to vary voltage on the fly, however I've run into a problem, regarding how I can get it to regulate both above and below the battery voltage using the same circuit.
I only need around 2-6 volts out of the product, at 1-1.75 amps (it will be closer to 1 most of the time)
I am aware of the necessity to up-rate components in the circuit. The accuracy of regulation is not hugely important to this application, nor is the smoothness of the supply
My thought was, perhaps I could run the mc34063 in it's inverting configuration, to avoid needing to both step up and down. is there anything I need to consider in using this config? Would any particular configuration be more or less efficient?
Perhaps someone could point me in the direction of a different regulator that'd suit my purpose better? My primary considerations are:
1) BOM cost (including the costs of additional components, I'd be happy to use a more expensive part if it saved on other BOM costs)
2) battery efficiency. I really don't want to get any worse than the 34063, better would make me a happy man.
I hope someone can provide me with some useful info, thank you very much in advance
Chris