Abstract: An effective method enhances energy saving at low load in a resonant converter with a hysteretic control scheme for implementing burst-mode at light load. The method causes a current controlled oscillator of the converter to stop oscillating when a feedback control current of the output voltage of the converter reaches a first threshold value, and introduces a nonlinearity in the functional relation between the frequency of oscillation and said feedback control current or in a derivative of the functional relation, while the control current is between a lower, second threshold value and the first threshold value, such that the frequency of oscillation remains equal or smaller than the frequency of oscillation when the control current is equal to the second threshold value. Several circuital implementations are illustrated, all of simple realization without requiring any costly microcontroller.

Abstract: An integrated control circuit of a switch is described, which is adapted to open or close a current path; said integrated circuit includes a comparator to compare a first signal with a second signal representative of the current flowing through said current path. The comparator outputs a third variable signal between a low logic level and a high logic level according to whether said second signal is lower than said first signal or vice versa; the integrated circuit has a driver to generate a signal to drive said switch in response to the third signal, and is configured to detect a spike on the leading edge of said second signal and to blank said third signal for a first blanking time period which depends on a turn-on delay of said switch and a second blanking period which depends on the duration of said spike on the leading edge of said second signal.

Abstract: A control device controls a switching circuit of a DC-DC converter. The switching circuit includes a half-bridge with at least first and second switches connected between an input voltage and a reference voltage. The converter comprises a transformer with a primary coupled with the center point of the half-bridge and a secondary coupled with a load. The control device comprises an error detector configured to determine an error signal representing a difference between a first signal representative of the voltage across the load and a first reference signal and a frequency controller configured to increase the switching frequency of the half-bridge when the error signal is kept below a second signal.

Abstract: An effective method enhances energy saving at low load in a resonant converter with a hysteretic control scheme for implementing burst-mode at light load. The method causes a current controlled oscillator of the converter to stop oscillating when a feedback control current of the output voltage of the converter reaches a first threshold value, and introduces a nonlinearity in the functional relation between the frequency of oscillation and said feedback control current or in a derivative of the functional relation, while the control current is between a lower, second threshold value and the first threshold value, such that the frequency of oscillation remains equal or smaller than the frequency of oscillation when the control current is equal to the second threshold value. Several circuital implementations are illustrated, all of simple realization without requiring any costly microcontroller.

Abstract: An effective method enhances energy saving at low load in a resonant converter with a hysteretic control scheme for implementing burst-mode at light load. The method causes a current controlled oscillator of the converter to stop oscillating when a feedback control current of the output voltage of the converter reaches a first threshold value, and introduces a nonlinearity in the functional relation between the frequency of oscillation and said feedback control current or in a derivative of the functional relation, while the control current is between a lower, second threshold value and the first threshold value, such that the frequency of oscillation remains equal or smaller than the frequency of oscillation when the control current is equal to the second threshold value. Several circuital implementations are illustrated, all of simple realization without requiring any costly microcontroller.

Abstract: An effective method enhances energy saving at low load in a resonant converter with a hysteretic control scheme for implementing burst-mode at light load. The method causes a current controlled oscillator of the converter to stop oscillating when a feedback control current of the output voltage of the converter reaches a first threshold value, and introduces a nonlinearity in the functional relation between the frequency of oscillation and said feedback control current or in a derivative of the functional relation, while the control current is between a lower, second threshold value and the first threshold value, such that the frequency of oscillation remains equal or smaller than the frequency of oscillation when the control current is equal to the second threshold value. Several circuital implementations are illustrated, all of simple realization without requiring any costly microcontroller.

Abstract: A control device controls a switching circuit of a DC-DC converter. The switching circuit includes a half-bridge with at least first and second switches connected between an input voltage and a reference voltage. The converter comprises a transformer with a primary coupled with the center point of the half-bridge and a secondary coupled with a load. The control device comprises an error detector configured to determine an error signal representing a difference between a first signal representative of the voltage across the load and a first reference signal and a frequency controller configured to increase the switching frequency of the half-bridge when the error signal is kept below a second signal.

Abstract: The present invention relates to a start up circuit for commutation power supplies (PWM) or DC/DC converters and to a commutation type power supply comprising such a start up circuit.

Abstract: The present invention relates to a start up circuit for commutation power supplies (PWM) or DC/DC converters and to a commutation type power supply comprising such a start up circuit.