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- Jan 21, 2010
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They are both options. I'm not familiar enough with these devices or your detailed requirements to be able to choose between them.
The texas instruments seems to have better efficiency but the difference is minimal, I cannot seem to find efficiency graphs on any datasheets from linear regulators though.
That's because switching regulators have a theoretical maximum efficiency of 100% (voltage in * current in = voltage out * current out, noting that current in will differ from current out) and there are a variety of issues (aside from quiescent current) which introduce losses. In comparison, the efficiency of a linear regulator is essentially determined by the inverse of the ratio between the input and output voltages.
As an example, a switch mode regulator could require 10V at 100mA in order to drive a load of 5V at 180mA. The efficiency requires you compare the input and output power, and in this case you'll get 90%. That extra 10% is lost in various forms which don't help the regulation.
An equivalent linear regulator would require 10V at 180mA to supply 5V at 180mA. The efficiency is 50%. In this case any losses in the regulator cause part of the losses we know we are causing anyway.
BTW, both examples ignored any power need to actually operate the regulator.
So these regulators along with the SPV1040 could be used? The board sats will just have direct regulation from the regulators and the mothership will charge the battery with the SPV1040 and an overdischarge/overcharge etc protection and then output via a regulator. I'll post a schematic asap since I'm not 100% sure on where capacitors go.
As long as you're not getting your power from a solar panel, these regulators are probably fine to operate a circuit from a lower voltage. However, they're probably not ideal to charge a battery (although, for a single charge cycle, you could do it).