摘要:
A control device for a resonant converter, the control device including a first circuit to integrate at least one signal indicating a half wave of a current circulating in a primary winding of a transformer; the first circuit is structured to generate at least a control signal of the switching circuit depending on the integrated signal. The control device includes a second circuit to impose the equality of a switching-on time period of the first and second switches.
摘要:
A control device for a resonant converter, the control device including a first circuit to integrate at least one signal indicating a half wave of a current circulating in a primary winding of a transformer; the first circuit is structured to generate at least a control signal of the switching circuit depending on the integrated signal. The control device includes a second circuit to impose the equality of a switching-on time period of the first and second switches.
摘要:
A resonant dc-dc converter converts dc input voltage to a dc output voltage. The converter includes switching, switching driving, conversion, and disabling circuits. The switching circuit receives the input voltage and generates a square wave voltage oscillating between the input voltage and a low value, at a frequency with a duty cycle. The switching driving circuit drives the switching circuit and includes a timing circuit for setting the frequency and the duty cycle. The timing circuit sets the value of the duty cycle to about 50% when the converter operates in steady state. The conversion circuit generates the output voltage from the square wave voltage based on the frequency and the duty cycle. The disabling circuit temporarily halts the timing circuit after a power on in such a way to temporarily vary the duty cycle of the square wave voltage during a period of the square wave voltage.
摘要:
A control device that controls a switching circuit and minimizes hard switching that occurs in the switching circuit of a half-bridge resonant converter having a high-side transistor and a low-side transistor. The control device is configured to turn the high-side and low-side transistor on and, so that a square-wave voltage is applied to a primary winding of a transformer. The controller starts the switching of the half-bridge converter by first turning on the low-side transistor for a first time period useful for pre-charging a bootstrap capacitor couplable to the middle point of the half-bridge, and then turning the low-side transistor and the high-side transistor off for a second time period that immediately follows and is longer than the first time period.
摘要:
A resonant dc-dc converter converts dc input voltage to a dc output voltage. The converter includes switching, switching driving, conversion, and disabling circuits. The switching circuit receives the input voltage and generates a square wave voltage oscillating between the input voltage and a low value, at a frequency with a duty cycle. The switching driving circuit drives the switching circuit and includes a timing circuit for setting the frequency and the duty cycle. The timing circuit sets the value of the duty cycle to about 50% when the converter operates in steady state. The conversion circuit generates the output voltage from the square wave voltage based on the frequency and the duty cycle. The disabling circuit temporarily halts the timing circuit after a power on in such a way to temporarily vary the duty cycle of the square wave voltage during a period of the square wave voltage.
摘要:
A control device controls a switching circuit for a converter. The switching circuit comprises a half-bridge having a high-side transistor and a low-side transistor. The control device comprises a controller configured to control turning on and turning off said two transistors, so that a square-wave voltage is applied to the transformer primary. The controller is configured to start switching the half-bridge by turning on the low-side transistor. The control device comprises a first timer configure to initially turn on the low-side transistor for a duration given by a first time period useful for pre-charging a bootstrap capacitor couplable to the middle point of the half-bridge, and a second timer configured to keep the low-side transistor and the high-side transistor turned off for a second time period immediately following the first time period and having a longer duration than the first time period.
摘要:
A control device for a resonant converter includes a first circuit structured to rectify a signal indicating the current circulating in the primary winding, a second circuit adapted to integrate at least the rectified signal and structured to generate at least a control signal of the switching circuit according to the integrated signal, and a third circuit adapted to send a reset command to the second circuit so as to inhibit the operation over a time period between the instant when the integrated signal reaches or exceeds a first signal and the instant of the next zero crossing of the signal, indicating the current circulating in the primary winding.
摘要:
A detecting device detects the midpoint voltage of a half bridge circuit of transistors. The circuit comprises a bootstrap capacitor having one terminal connected to the midpoint node of the half bridge circuit and another terminal connected to a supply circuit. The device comprises a further capacitor connected between a second terminal of the bootstrap capacitor and circuit means adapted to form a low impedance node for a current signal circulating in said further capacitor during the transitions from the low value to the high value and from the high value to the low value of the midpoint voltage. The device comprises a detector to detect said current signal circulating in said further capacitor and to output at least a first signal indicating the transitions from the low value to the high value or from the high value to the low value according to said current signal.
摘要:
A control device for a resonant converter includes a first circuit structured to rectify a signal indicating the current circulating in the primary winding, a second circuit adapted to integrate at least the rectified signal and structured to generate at least a control signal of the switching circuit according to the integrated signal, and a third circuit adapted to send a reset command to the second circuit so as to inhibit the operation over a time period between the instant when the integrated signal reaches or exceeds a first signal and the instant of the next zero crossing of the signal, indicating the current circulating in the primary winding.
摘要:
A detecting device detects the midpoint voltage of a half bridge circuit of transistors. The circuit comprises a bootstrap capacitor having one terminal connected to the midpoint node of the half bridge circuit and another terminal connected to a supply circuit. The device comprises a further capacitor connected between a second terminal of the bootstrap capacitor and circuit means adapted to form a low impedance node for a current signal circulating in said further capacitor during the transitions from the low value to the high value and from the high value to the low value of the midpoint voltage. The device comprises a detector to detect said current signal circulating in said further capacitor and to output at least a first signal indicating the transitions from the low value to the high value or from the high value to the low value according to said current signal.