Abstract: An electronic device includes first and second transistors coupled in series between first and second source voltage levels. An inductor is coupled between a node coupling the first and second transistors and a load. Control logic is operative to generate control pulses operative to switch the first and second transistors. The controller generates the control pulses as a continuous stream of control pulses in a continuous conduction mode, and skips generation of some control pulses in a discontinuous conduction mode in response to a pulse skipping signal. A pulse skipping circuit is operative to generate a sense voltage as a function of an inductor current in the inductor, compare the sense voltage to ground, and generate a pulse skipping signal to the control logic when the sense voltage is below ground.

Abstract: A method supplies power from a power source to a load. The method includes, in a first mode, electrically coupling a step-down converter node of a step-down converter alternately to the power source via a conductive bypass path that bypasses a step-up converter and to ground. The step-up converter has an input electrically coupled to the power source and the step-down converter has an output electrically coupled to the load. The method further includes, in a second mode, coupling the step-down converter node alternately to the power source via the bypass path and to an output of the step-up converter.

Abstract: An electronic device includes first and second transistors coupled in series between first and second source voltage levels. An inductor is coupled between a node coupling the first and second transistors and a load. Control logic is operative to generate control pulses operative to switch the first and second transistors. The controller generates the control pulses as a continuous stream of control pulses in a continuous conduction mode, and skips generation of some control pulses in a discontinuous conduction mode in response to a pulse skipping signal. A pulse skipping circuit is operative to generate a sense voltage as a function of an inductor current in the inductor, compare the sense voltage to ground, and generate a pulse skipping signal to the control logic when the sense voltage is below ground.

Abstract: A DC-DC converter transitions between continuous conduction mode (CCM) and discontinuous conduction mode (DCM) without causing any overshoot or undershoot deviation output voltage. The DC-DC converter operates in a PWM mode in CCM. During DCM, it skips PWM pulses when a sustained negative current is detected in an output inductor. The current sensing is achieved by sampling and integrating a voltage, the sign of which is inverse to current direction. The sample and hold and integrator circuits are small, simple, and scale to high frequencies. The pulse skipping circuit automatically adjusts the duty cycle of power pulses to force a zero inductor current at the end of each pulse.

Abstract: A method supplies power from a power source to a load. The method includes, in a first mode, electrically coupling a step-down converter node of a step-down converter alternately to the power source via a conductive bypass path that bypasses a step-up converter and to ground. The step-up converter has an input electrically coupled to the power source and the step-down converter has an output electrically coupled to the load. The method further includes, in a second mode, coupling the step-down converter node alternately to the power source via the bypass path and to an output of the step-up converter.

Abstract: A DC-DC converter transitions between continuous conduction mode (CCM) and discontinuous conduction mode (DCM) without causing any overshoot or undershoot deviation output voltage. The DC-DC converter operates in a PWM mode in CCM. During DCM, it skips PWM pulses when a sustained negative current is detected in an output inductor. The current sensing is achieved by sampling and integrating a voltage, the sign of which is inverse to current direction. The sample and hold and integrator circuits are small, simple, and scale to high frequencies. The pulse skipping circuit automatically adjusts the duty cycle of power pulses to force a zero inductor current at the end of each pulse.

Abstract: A synchronous rectifier, including an energy storage element having a terminal; a power supply input, connected to the terminal of the storage element in a first time interval; a reference line connected to the terminal of the storage element in a second time interval; and a zero comparator, coupled to the terminal of the storage element to detect a current flowing in the energy storage element and disconnect the terminal of the storage element from the reference line upon detecting a zero current, the zero comparator having an offset and a propagation time; the zero comparator further having an offset control input and an output. An offset regulating loop is coupled between the output of the zero comparator and the offset control input and regulates the offset of the zero comparator to compensate the propagation time.

Abstract: A synchronous rectifier, including an energy storage element having a terminal; a power supply input, connected to the terminal of the storage element in a first time interval; a reference line connected to the terminal of the storage element in a second time interval; and a zero comparator, coupled to the terminal of the storage element to detect a current flowing in the energy storage element and disconnect the terminal of the storage element from the reference line upon detecting a zero current, the zero comparator having an offset and a propagation time; the zero comparator further having an offset control input and an output. An offset regulating loop is coupled between the output of the zero comparator and the offset control input and regulates the offset of the zero comparator to compensate the propagation time.