Gandledorf said:
How would one figure out the working voltage range then, when one could reliably draw 5V @500mA? The general data sheet for this device is here:
https://www.electro-tech-online.com/custompdfs/2004/01/tps7150-2.pdf, I'm just a little unclear as to what I am looking for to determine this. I'm interested in the TPS7150 series.
EDIT: On page 16 there is a graph of input vs. output which I missed, do I correctly assume that I can expect 5V regulated output @ 500mA until my pack hits 5V?
If you zoom in on that graph, you'll see that when your input gets down to 5v, your output will be
about 4.9v. Figure 8 on p.15 shows that the dropout voltage at 500ma is 130mv, so your output will start to drop when your input reaches 5.13v. These numbers are
typical, not guaranteed. Keep in mind that your circuit will probably work down to at least 4.5v, possibly lower.
The TPS7150 is not a switching regulator. If you want maximum battery life, you should probably use a switcher.