I am trying to figure out the best possible circuit for MCP16251/2 feeding from 2 AA batteries in series with an output of 3.3v. MCP is extremely efficient boost converter with very low quiescent current which is ideal for my low-power battery application, however my problem is that two fresh AA batteries in series can potentially output higher voltage at the beginning of their lifespan than the Output setting of 3.3v used in my MCP16251/2 set-up. What are the potential consequences of having this overvoltage on the input pin? Unfortunately the datasheet does not mention anything for such scenario except for:
"Output Quiescent Current: < 4 µA typical, device is not switching (VOUT > VIN, excluding feedback divider current) For VIN > VOUT, VOUT will not remain in regulation." ...and I am not exactly sure how to interpret that. Will the chip just act as a pass-through or act funky in any way?
I suspect that the converter just won't regulate any voltage and act as pass-through, but just curious if this set up can damage the boost converter in any way? Any suggestions - theoretical or based on experience would be highly appreciated!
Attached is my current schematics based on somewhat improved reference design: