I'm working on a project that requires 3.3V from a pair of double AAs. I had thought that LDOs were always buck and if you needed boost you had to use a switching regulator. While doing some research for this project I came across the TPS736 line of LDOs from TI and now I'm confused.


Reading the datasheet leads me to believe that I can get 3.3V from 2 AAs as they run down to the minimum input voltage of 1.7V. Am I reading that right?

  • 3
    \$\begingroup\$ An LDO regulator may also be a buck switching regulator but usually it is a linear (non-switching) regulator. In no way, shape or form can the voltage regulator specified produce 3.3 volts from a smaller input. It is a linear regulator not a switcher. \$\endgroup\$
    – Andy aka
    Commented May 24, 2015 at 14:15

1 Answer 1


At the bottom of Table 6.5, on page 6 of the datasheet, it says:

(1) Minimum V\$_{IN}\$ = V\$_{OUT}\$ + V\$_{DO}\$ or 1.7V, whichever is greater.

So V\$_{IN}\$ cannot be less than V\$_{OUT}\$. So it is a regular LDO.

The datasheet is not written very well.


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