According to its datasheet, the TPS43061 "is a low Iq current-mode synchronous boost controller with wide-input voltage range". My intent is to use this controller to boost and regulate the stepped-down and rectified mains voltage from 12.6 V to 15 V, supplying up to 6 A output.
Under "Power Supply Recommendations" in Section 10 of the datasheet, it says that "[the] input supply should be well regulated." How regulated is "well" regulated? There doesn't appear to be a line regulation parameter in the electrical characteristic section.
My guess is that the "well regulated" part means that the input voltage ripple should not exceed some designed amount, and indeed the minimum input voltage is used in calculating the values for various external components.
Can I assume, living in the United States, that the mains voltage will be stable enough to follow this recommendation, assuming that the output of the rectifier has enough capacitance?
Best Answer
If the input supply isn't well regulated, under some loading conditions its voltage may drop too low and cause the booster circuit to try and take significantly more current from the input supply (in order to maintain the boosted output voltage on its own load) and this rapidly spirals into either failure of the input supply or some kind of oscillation on the booster output.
In other words, when using a voltage booster either take care to prevent sudden changes in output load current inflicting even greater changes on the current taken from the input voltage supply or use a powerful input supply that has inherently good regulation.