Dc-dc converter

A DC-DC conversion method using a DC-DC conversion scheme comprising a buck converter including a first switch connected in series with a first inductor, the first switch and first inductor providing a switched connected between an input and an output, a second switch being connected across output, and a DC boost arrangement connected between the first switch and the first inductor, the DC boost arrangement comprising second and third magnetically linked inductors, the second inductor being connected in series between the first switch and the first inductor, and the third inductor being electrically connected to a point intermediate the first and second inductors, the windings of the second and third inductors being such that a change in current flowing through the second inductor induces a boost current in the third inductor supplementing the current flowing through the second inductor, the method comprising the steps of repeatedly opening and closing the first switch such that, when the first switch is closed, a changing current flowing through the second inductor induces a current in the third inductor supplementing that flowing through the second inductor, thereby boosting the current supplied to the Buck converter.

A DC-DC conversion scheme comprising a main inductor, a first circuit leg and a second circuit leg, each circuit leg including a primary switch, a secondary switch and a primary inductor, the primary switch and the primary inductor of each leg being connected in series with the main inductor between an input and an output, the secondary switch of each leg providing a switched ground connection, connected to a point intermediate the associated primary switch and the primary inductor of the associated leg, and wherein the primary inductors of the first and second legs are magnetically linked.

The method of operation of a circuit of the type comprising a main inductor, a first circuit leg and a second circuit leg, each circuit leg including a primary switch, a secondary switch and a primary inductor, the primary switch and the primary inductor of each leg being connected in series with the main inductor between an input and an output, the secondary switch of each leg providing a switched ground connection, connected to a point intermediate the associated primary switch and the primary inductor of the associated leg, and wherein the primary inductors of the first and second legs are magnetically linked, wherein during at least certain phases of operation both of the primary switches or both of the secondary switches simultaneously occupy closed conditions.