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1. A control device for a switching voltage regulator comprising a switching circuit, the control device comprising: a first input configured to receive a measure signal representative of an output voltage of the switching circuit; an error detector, configured to generate a voltage error signal representative of only a nominal signal minus the measure signal; a proportional-integral (PI) controller, coupled to the error detector and configured to generate a single voltage control signal representative of only an average error of the voltage error signal; a triangular signal generator configured to receive a detection voltage proportional to an inductor current flowing in the switching circuit, and to generate first and second periodic reference signals; a Buck modulator, coupled to the PI controller and configured to compare the single voltage control signal with the first periodic reference signal and to generate at least one first pulse width modulated signal for the switching circuit; and a Boost modulator, coupled to the PI controller and configured to compare the single voltage control signal with the second periodic reference signal and to generate at least one second pulse width modulated signal for the switching circuit; wherein the first and second periodic reference signals have a same period T, same amplitude range, same phase, and different maximum and minimum values; wherein the maximum value of the first periodic reference signal is lower than the single voltage control signal in a Boost control mode; wherein the minimum value of the second periodic reference signal is higher than the single voltage control signal in a Buck control mode; wherein the maximum value of the first periodic reference signal and the minimum value of the second periodic reference signal are higher and lower, respectively, than the single voltage control signal in a transient control mode between the Buck control mode and the Boost control mode; wherein the first pulse width modulated signal switches between on and off control values in the Buck control mode and in the transient control mode; wherein the second pulse width modulated signal switches between the on and off control values in the Boost control mode and in the transient control model wherein a duty cycle of the switching voltage regulator has a Buck-Boost state space comprising: normalized values for a pure Boost mode control in an abscissa line and normalized values for a pure Buck mode control in an ordinate line; a 45°-inclined straight portion line formed by ideal duty cycle transition values between the pure Boost control mode and the pure Buck control mode via a Buck-Boost control mode; and a first straight limit line disposed between a Buck duty cycle maximum and a unity duty cycle for the pure Boost mode control, and a second straight limit line disposed between a Boost duty cycle minimum and the unity duty cycle for the pure Boost mode control and wherein the PI controller is further configured to control a continuous smooth transition along one or more curves within a first triangle formed by the pure Buck mode control abscissa line, the 45°-inclined straight portion line, and the first straight limit line, and within a second triangle formed by the 45°-inclined straight portion line, the second straight limit line, and the pure Boost mode control ordinate line.
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