A step-up/step-down switching regulator control method for a regulator
having an inductor with first and second leads, a first switch for
controllably coupling the first lead to a source of power, a first device
between the first lead and a circuit ground, a second switch for
controllably coupling the second lead to the circuit ground, and a second
device between the second lead and a regulator, the method comprising
operating the switches in a sequence of phases when the source of power
has a voltage exceeding the regulator output and in the same sequence of
phases when the source of power has a voltage less than the regulator
output, the phases being phase 1 with the first and second switches
closed, phase 2 with the first switch closed and the second switch open,
and phase 3 with both switches open. The first and second devices may be
switches or diodes. Various embodiments are disclosed.