Abstract: According to an embodiment, a flyback converter includes a transformer, a power switch coupled to the primary winding of the transformer, and a controller. The controller comprises a voltage-dependent current source, a reference capacitor, comparators, and logic circuitry. The controller estimates the primary inductance of the transformer based on the voltage across the reference capacitor, detects a saturation condition based on the estimated inductance and primary current, and implements a protection mechanism in response. The controller can distinguish between genuine overload conditions and potential magnetic tampering attempts. The protection mechanism may involve increasing the switching frequency. The controller may include an adjustable transconductance to set the saturation detection threshold and implement a delay before activating protection. This allows for more targeted protection against core saturation and magnetic interference while maintaining normal operation under high-load conditions.

Abstract: According to an embodiment, a flyback converter includes a transformer, a power switch coupled to the primary winding of the transformer, and a controller. The controller comprises a voltage-dependent current source, a reference capacitor, comparators, and logic circuitry. The controller estimates the primary inductance of the transformer based on the voltage across the reference capacitor, detects a saturation condition based on the estimated inductance and primary current, and implements a protection mechanism in response. The controller can distinguish between genuine overload conditions and potential magnetic tampering attempts. The protection mechanism may involve increasing the switching frequency. The controller may include an adjustable transconductance to set the saturation detection threshold and implement a delay before activating protection. This allows for more targeted protection against core saturation and magnetic interference while maintaining normal operation under high-load conditions.

Abstract: A control circuit for a switching stage of an electronic converter a driver circuit configured to generate one or more drive signals as a function of a Pulse-Width Modulation (PWM) signal and a PWM signal generator circuit configured to generate the PWM signal. A first comparator asserts a comparison signal when a feedback signal having a voltage being indicative of a current flowing through an inductance of the switching stage is greater than a reference signal. In response to a clock signal, a storage element asserts the PWM signal, whereby the clock signal indicates the duration of the switching period of the PWM signal. Conversely, in response to determining that the comparison signal is asserted, the storage element de-asserts the PWM signal.

Abstract: Provided is a power supply control circuit for a power supply, including a PFC converter configured to generate a bus voltage, an electronic converter and an auxiliary power supply configured to generate an auxiliary supply voltage. The PFC converter comprises a PFC control circuit configured to drive the PFC converter to regulate the bus voltage to a requested value. When the output power is greater than the threshold, the power supply control circuit supplies the PFC control circuit with the auxiliary supply voltage. When the output power is smaller than the threshold, the circuit compares the bus voltage to upper and lower thresholds. When the bus voltage is greater than the upper threshold, the circuit inhibits supply of the PFC control circuit with the auxiliary supply voltage. When the bus voltage is smaller than a lower threshold, the circuit supplies the PFC control circuit with the auxiliary supply voltage.

Abstract: A control circuit for an electronic converter is generates a drive signal of the electronic converter by setting the drive signal to a first logic level in response to a switch-on signal, and to a second logic level in response to a switch-off signal. The control circuit comprises a valley detection circuit and a combinational logic circuit. The control circuit comprises a blanking circuit configured to generate the blanking signal by determining a blanking time, and asserting the blanking signal when the blanking time elapses since the start of the switch-on or the switch-off interval. The control circuit comprises a blanking time adaption circuit to adapt the blanking time as a function of a blanking time adaption signal based on the input voltage, and to increase the blanking time when the input voltage increases, and decrease the blanking time when the input voltage decreases.

Abstract: A control circuit for a switching stage of an electronic converter is described. The control circuit includes a driver circuit configured to generate one or more drive signals as a function of a Pulse-Width Modulation, PWM, signal and a PWM signal generator circuit configured to generate the PWM signal. A first comparator asserts a comparison signal when a feedback signal having a voltage being indicative of a current flowing through an inductance of the switching stage is greater than a reference signal. In response to a clock signal, a storage element asserts the PWM signal, whereby the clock signal indicates the duration of the switching period of the PWM signal. Conversely, in response to determining that the comparison signal is asserted, the storage element de-asserts the PWM signal. Specifically, the reference signal is generated as a function of the voltage at a capacitance.

Abstract: A control circuit for a driving an electronic switch associated with a switching node of a flyback converter includes a comparison circuit configured to generate a switch-off signal by comparing a current measurement signal with a current measurement threshold signal. A valley detection circuit is configured to generate a trigger in a trigger signal when a valley signal indicates a valley in a voltage at the switching node of the flyback converter, and a blanking circuit is configured to generate a switch-on signal by combining the trigger signal with a timer signal provide by a timer circuit. The timer signal indicates whether a blanking time-interval has elapsed.

Abstract: A control circuit for an electronic converter is described. The control circuit generates a drive signal for an electronic switch of the electronic converter by setting the drive signal to a first logic level in response to a switch-on signal, thereby closing said electronic switch for a switch-on interval, and to a second logic level in response to a switch-off signal, thereby opening the electronic switch for a switch-off interval. The control circuit comprises a valley detection circuit configured to generate a trigger in a trigger signal in response to detecting a valley in the voltage at the electronic switch during the switch-off interval, and a combinational logic circuit configured to generate the switch-on signal by masking the trigger signal in response to a blanking signal.

Abstract: A control circuit for a driving an electronic switch associated with a switching node of a flyback converter includes a comparison circuit configured to generate a switch-off signal by comparing a current measurement signal with a current measurement threshold signal. A valley detection circuit is configured to generate a trigger in a trigger signal when a valley signal indicates a valley in a voltage at the switching node of the flyback converter, and a blanking circuit is configured to generate a switch-on signal by combining the trigger signal with a timer signal provide by a timer circuit. The timer signal indicates whether a blanking time-interval has elapsed.

Abstract: A control circuit for a driving an electronic switch associated with a switching node of a flyback converter includes a comparison circuit configured to generate a switch-off signal by comparing a current measurement signal with a current measurement threshold signal. A valley detection circuit is configured to generate a trigger in a trigger signal when a valley signal indicates a valley in a voltage at the switching node of the flyback converter, and a blanking circuit is configured to generate a switch-on signal by combining the trigger signal with a timer signal provide by a timer circuit. The timer signal indicates whether a blanking time-interval has elapsed.

Abstract: A control circuit for a driving an electronic switch associated with a switching node of a flyback converter includes a comparison circuit configured to generate a switch-off signal by comparing a current measurement signal with a current measurement threshold signal. A valley detection circuit is configured to generate a trigger in a trigger signal when a valley signal indicates a valley in a voltage at the switching node of the flyback converter, and a blanking circuit is configured to generate a switch-on signal by combining the trigger signal with a timer signal provide by a timer circuit. The timer signal indicates whether a blanking time-interval has elapsed.

Abstract: A method of controlling an output voltage of a pulse width modulation (PWM) converter with a PWM signal driving a power switch of the converter may include using a comparator to compare a reference voltage with a scaled output voltage of the converter, incrementing or decrementing an up/down counter at each pulse of a clock signal applied to the counter depending on a state of the comparator, and controlling the comparator to generate the PWM signal with a control voltage selected from a look-up table using a value of the counter.

Abstract: A method of controlling an output voltage of a pulse width modulation (PWM) converter with a PWM signal driving a power switch of the converter may include using a comparator to compare a reference voltage with a scaled output voltage of the converter, incrementing or decrementing an up/down counter at each pulse of a clock signal applied to the counter depending on a state of the comparator, and controlling the comparator to generate the PWM signal with a control voltage selected from a look-up table using a value of the counter.