Patent ID: 7298116

Claim:
A multi-output DC-DC converter comprising: an inductor, a main switch for periodically coupling a DC-input voltage to the inductor, a plurality of output switches coupled to the inductor, each one for generating an associated one of a plurality of output voltages to an associated one of a plurality of loads, and a controller for controlling the main switch and the output switches in a sequence of cycles, each one of the cycles comprising an on-phase of the main switch followed by an on-phase of one of the plurality of the output switches the controller comprising: a plurality of comparators each one for comparing an associated one of the plurality of output voltages with an associated one of a plurality of reference voltages, means for determining whether a number of the output voltages which have a value above their associated reference voltage is larger than, smaller than, or equal to a number of the plurality of output voltages which have a value below their associated reference voltage, means for generating the cycles either with a first duty cycle or a second duty cycle being larger than the first duty cycle to obtain a first number of cycles with the first duty cycle and a second number of cycles with the second duty cycle, the first number being: (1) larger than the second number if the number of the output voltages which have a value above, their associated reference voltage is larger than the number of the plurality of output voltages which have a value below their associated reference voltage; (2) smaller than the second number if the number of the output voltages which have a value above their associated reference voltage is smaller than the number of the plurality of output voltages which have a value below their associated reference voltage; or (3) equal to the second number the second number if the number of the output voltages which have a value above their associated reference voltage is equal to the number of the plurality of output voltages which have a value below their associated reference voltage.