There is provided a power supply device configured to boost an input voltage to output an output voltage, the power supply device including: an oscillator circuit configured to receive the input voltage and to output an oscillation signal; a step-up circuit configured to output a boost voltage based on the oscillation signal; a first hysteresis comparator and a second hysteresis comparator configured to compare boost voltages with threshold values; a first switch that is connected between the oscillator circuit and the step-up circuit and that is controlled based on a comparison result of the first hysteresis comparator; and a second switch that is connected to an output terminal configured to output the output voltage and that is controlled based on a comparison result of the second hysteresis comparator.

A half bridge DC-DC converter device includes a primary circuit and a secondary circuit, which include separate windings that are disposed around a magnetic core. The first circuit includes two switches and a drive circuit to turn the two switches on and off in an alternating fashion. The primary circuit further includes two thermal regulating components to regulate the current at the base of the two switches over a range of operating temperatures. The regulation of base current over a range of different operating temperatures results in the half bridge converter device being efficient and maintaining a stable switching frequency over the operational temperature range.

A DC-DC converter includes: an transformer having a primary winding and a secondary winding magnetically coupled to the primary winding; a power oscillator applying an oscillating signal to the primary to transmit a power signal to the secondary winding; a rectifier connected to the secondary winding of the transformer to obtain an output DC voltage by rectification of the power signal; comparison circuitry to generate an error signal representing a difference between the output DC voltage and a reference voltage; a transmitter connected to the secondary winding of the transformer to apply an amplitude modulation to the power signal at the secondary winding of the transformer in response to the error signal to thereby produce an amplitude modulated signal at the primary winding; and a receiver and control circuit connected to the primary winding to control an amplitude of the oscillating signal as a function of the amplitude modulated signal.

A DC-DC converter includes: an transformer having a primary winding and a secondary winding magnetically coupled to the primary winding; a power oscillator applying an oscillating signal to the primary to transmit a power signal to the secondary winding; a rectifier connected to the secondary winding of the transformer to obtain an output DC voltage by rectification of the power signal; comparison circuitry to generate an error signal representing a difference between the output DC voltage and a reference voltage; a transmitter connected to the secondary winding of the transformer to apply an amplitude modulation to the power signal at the secondary winding of the transformer in response to the error signal to thereby produce an amplitude modulated signal at the primary winding; and a receiver and control circuit connected to the primary winding to control an amplitude of the oscillating signal as a function of the amplitude modulated signal.

The present disclosure provides a starter circuit for energy harvesting circuits for an energy source having a first and a second potential of an input voltage, in particular for thermoelectric generators.

The present disclosure provides a starter circuit for energy harvesting circuits for an energy source having a first and a second potential of an input voltage, in particular for thermoelectric generators.

A power converter apparatus is provided with: a plurality of leg circuits, each including two switch circuits connected in series between input terminals; a transformer including a primary winding and a secondary winding, the primary winding having a first terminal and a second terminal; and at least one capacitor. The at least one capacitor is connected between the first terminal or the second terminal of the primary winding of the transformer, and a node between the two switch circuits in at least one leg circuit among the plurality of leg circuits. The first terminal of the primary winding of the transformer is connected to at least two nodes between the switch circuits in at least two first leg circuits among the plurality of leg circuits, via at least two first circuit portions having at least one of capacitances and inductances different from each other, respectively.

The present invention concerns a power converter including: a capacitor (CBUS) having first and second electrodes respectively coupled to first (E1) and second (E2) input terminals via a current-limiting element (R1, L1); at least one normally-on transistor (K1, K2, K3, K4, K5, K6); a circuit (170) for powering a circuit (CMD_K1, CMD_K2) for controlling the normally-on transistor; and a switch configurable to, in a first configuration, couple first (g) and second (h) input terminals of the power supply circuit (170) respectively to the first (E1) and second (E2) input terminals of the converter, upstream of the current-limiting element (R1, l1) and, in a second configuration, connect the first (g) and second (h) input terminals of the power supply circuit (170) respectively to the first and second electrodes of the capacitor, downstream of the current-limiting element (R1, L1).

Methods and systems for controlling an output voltage of a resonant converter during a light load condition. One such method includes generating a normalised conduction time of the resonant converter that varies inversely with a switching frequency of the resonant converter by continuing to operate the resonant converter in a Pulse Frequency Modulation mode at a low switching frequency that is similar to the resonant frequency. The method also includes controlling a power level delivered to a secondary winding of a transformer positioned between a resonant tank and an output rectifier of the resonant converter by regulating the normalised conduction time, where the delivered power level is variable based on load conditions. The method further includes generating an output voltage using the output rectifier wherein the magnitude of the output voltage corresponds to the power level delivered to the secondary winding.

In a described example, a circuit includes a mode control circuit having an input and a mode control output. The mode control output is adapted to be coupled to a mode input of a DC-to-DC power converter. The mode control circuit is configured to provide a mode control signal at the mode control output. The mode control signal has a frequency and a duty cycle for causing the power converter to operate within an inaudible frequency range by transitioning the power converter between a power save mode and a pulse width modulation (PWM) mode. The mode control circuit is configured to control the duty cycle responsive to the input of the mode control circuit.