Abstract:
A control circuit includes: an output terminal configured to be coupled to a control terminal of a transistor that has a current path coupled to an inductor; a transconductance amplifier configured to produce a sense current based on a current flowing through the current path of the transistor; and a first capacitor, where the control circuit is configured to: turn on the transistor based on a clock signal, integrate the sense current with an integrating capacitor to generate a first voltage, generate a second voltage across the first capacitor based on a first current, generate a second current based on the second voltage, generate a third voltage based on the second current, turn off the transistor when the first voltage becomes higher than the third voltage; discharge the integrating capacitor when the transistor turns off; and regulate an average output current flowing through the inductor based on the first current.
Abstract:
A control device controls a switching converter having an input alternating supply voltage and a regulated direct voltage at the output terminal. The converter comprises a switch and the control device is adapted to control the on time period and the off time period of said switch for each cycle. The control device has a first input signal representative of the current flowing through at least one element of the converter and comprises a zero crossing detector adapted to detect at least one pair of first and second zero crossings of said first signal for each switching cycle, said second zero crossing immediately following the first zero crossing and occurring in opposite direction with respect to the first zero crossing. The control device comprises a synchronizer adapted to synchronize the start of the on period with each second zero crossing of said first signal.
Abstract:
A PWM controlled multi-phase resonant voltage converter may include a plurality of primary windings powered through respective half-bridges, and as many secondary windings connected to an output terminal of the converter and magnetically coupled to the respective primary windings. The primary or secondary windings may be connected such that a real or virtual neutral point is floating.
Abstract:
A method and a controller for controlling a converter are provided. In the method and controller, a capacitance is charged simultaneously using a first current and a second current that is different than the first current or discharged simultaneously using the first current and the second current. Sourcing and sinking transistors source or sink the first current for charging or discharging the capacitance. An operational transconductance amplifier determines a level of the second current based on a level of current flowing through the resonant tank. The operational transconductance amplifier sources or sinks the second current for charging or discharging the capacitance. Further, logic is provided to output a switching signal for operating the converter based on a voltage across the capacitance.
Abstract:
A power control module for an electronic converter is disclosed. The electronic converter includes a power stage comprising two input terminals for receiving a first power signal and two output terminals for providing a second power signal. The electronic converter includes, moreover, a control circuit configured to control operation of the power stage as a function of a feedback control signal. In particular, the power control module includes a pre-elaboration module configured to generate a reference signal as a function of the feedback control signal and a first signal being representative of a voltage applied to the two input terminals. An error amplifier is configured to generate a modified control signal as a function the reference signal and a second signal being representative of a current flowing through the two input terminals.
Abstract:
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.
Abstract:
The present disclosure is directed to a switching power converter having a regulated output voltage or output current. The power converter uses a control unit having a signal conditioning circuit to produce a control voltage signal, which is used to drive a power stage of the converter. The signal conditioning circuit includes a comparator that compares a measured electrical quantity to a reference value representative of a desired regulated output quantity, and produces a digital detection signal based on the comparison. A control actuator uses the digital detection signal to produce a correction signal, which is received by an averaging circuit. The averaging circuit then produces the control voltage signal based on an average of the correction signal.
Abstract:
A power control module for an electronic converter is disclosed. The electronic converter includes a power stage comprising two input terminals for receiving a first power signal and two output terminals for providing a second power signal. The electronic converter includes, moreover, a control circuit configured to control operation of the power stage as a function of a feedback control signal. In particular, the power control module includes a pre-elaboration module configured to generate a reference signal as a function of the feedback control signal and a first signal being representative of a voltage applied to the two input terminals. An error amplifier is configured to generate a modified control signal as a function the reference signal and a second signal being representative of a current flowing through the two input terminals.
Abstract:
The present disclosure is directed to a primary-controlled high power factor quasi resonant converter. The converter converts an AC power line input to a DC output to power a load, generally a string of LEDs, and may be compatible with phase-cut dimmers. The power input is fed into a transformer being controlled by a power switch. The power switch is driven by a controller having a shaping circuit. The shaping circuit uses a current generator, switched resistor and capacitor to produce a reference voltage signal. The controller drives the power switch based on the voltage reference signal, resulting in a sinusoidal input current in a primary winding of the transformer, resulting in high power factor and low total harmonic distortion for the converter.
Abstract:
A method of controlling a switching converter and a related controller suitable for the switching converter allow to implement a burst-mode functioning without generating acoustic noise and with a relevantly reduced ripple of the regulated DC voltage or current provided in output to a supplied load. The method includes sensing the difference between the error signal and the burst-stop threshold at the beginning of a burst period. If the error signal has surpassed (either upwards or downwards) the burst-stop threshold, the method sets the switching stage in a high impedance state at a new active edge of a clock signal, keeps the switching stage in the high impedance state for an integer number of cycles of the clock signal, and re-enables the switching stage to switch the energy tank circuit up to the end of the burst period. The integer number is determined based on the difference between the error signal and the burst-stop threshold.