Patent ID: 7081740

Claim:
A switched-mode DC/DC converter producing at least one output voltage (Vout), comprising: At least one power stage (PS) for the purpose of converting an input voltage (Vin) into an output voltage (Vout), each power stage including at least one controllable switching device (CS); and A control device (CD) for the purpose of turning ON and turning OFF said controllable switching device, characterized in that Owing to the temporal resolution of the control device, Δt, both the turn ON and turn OFF times of the controllable switching device are constrained to be integral multiples of Δt; and A duty cycle control mechanism (DC) for controlling the duty cycle of said controllable switching device, comprising: A mechanism for estimating the target duty cycle, the target duty cycle being the duty cycle essential to achieve the desired output voltage (Vdo); and A duty cycle quantization mechanism (DQ) for determining, for a target duty cycle estimate, a set of two quantized ON time/OFF time pairs suitable for controlling said controllable switching device, characterized in that the quantized ON time and OFF time of each pair (in said set) are determined independently of each other; that is, the sum of the ON time and OFF time is not fixed; and may vary, pair to pair, constrained to a set of discrete values {Tswi} (i=1, 2, . . . I) where Tswi is an integral multiple of Δt; and A sequencing mechanism (SM) for determining the turn ON and turn OFF times of said controllable switching device by choosing, cycle by cycle, an ON time/OFF time pair from said set of two ON time/OFF time pairs, choosing in such a manner that the time-averaged value of the resultant duty cycle is equivalent or nearly equivalent to the estimated target duty cycle.