For a programmable direct current (DC)-DC converter application, a driver system includes a switched mode power circuit for providing a DC power signal to an electrical load and a control block. Control block includes interfaces coupled to receive at least one real-time input signal from a low voltage region of the switched mode power circuit and to provide at least one control signal to the low voltage region. Control block configures the switched mode power circuit to provide the DC power signal having at least one power parameter within a tolerance of a power configuration setting value of the electrical load. Control block responds to the at least one real-time input signal from the low voltage region to adjust operation of the low voltage region via the at least one control signal. Low voltage region can include a plurality of switched converter circuits.

A bleeder current control method. The bleeder current control method includes the following steps: The rectifier bridge transmits a post-bridge input signal to the power system. The shaping circuit obtains the post-bridge input signal and shapes it into a bleeder current reference signal, the bleeder current reference signal is inversely correlated with the initial post-bridge input signal. Acquiring a current sampling signal representing the bleeder current, and comparing the error of the current sampling signal with the bleeder current reference signal to obtain an error signal. The current sampling signal is controlled according to the error signal, so that the current sampling signal is output based on the waveform of the bleeder current reference signal. Thus, a reliable and full-time sine wave envelope signal is provided to the power system, so as to reduce the loss caused by the bleeder current to the power system.

A circuit includes two thyristors coupled in anti-series. An AC capacitor has first and second electrodes respectively coupled to two different electrodes of the two thyristors. The first and second electrodes are coupled to receive an AC voltage. A control circuit detects discontinuance of application of the AC voltage to the AC capacitor and in response thereto simultaneously applies same gate currents to the two thyristors. A current path through the two thyristors (one passing current in forward mode and the other in reverse mode) discharges a residual voltage stored on the AC capacitor.

A circuit includes two input nodes and two output nodes. A rectifier bridge is coupled to the input and output nodes. The rectifier bridge includes a first and second thyristors and a third thyristor coupled in series with a resistor in series. The series coupled third thyristor and resistor are coupled in parallel with one of the first and second thyristors. The first and second thyristors are controlled off, with the third thyristor controlled on, during start up with resistor functioning as an in in-rush current limiter circuit. In normal rectifying operation mode, the first and second thyristors are controlled on, with the third thyristor controlled off.

A control circuit for a power factor correction (PFC) circuit, the control circuit includes a multiplier having first, second, and third multiplier inputs and a multiplier output. The control circuit has an adder having first and second inputs and an output. The first input of the adder is coupled to the multiplier output. The control circuit further includes a root mean square (RMS) calculation circuit configured to determine a square of a root mean square of an input sinusoidal voltage. The RMS calculation circuit has an output coupled to the second multiplier input. An input voltage square calculation circuit is configured to determine a square of the input sinusoidal voltage. The input voltage square calculation circuit has an output coupled to the third multiplier input.

Multilevel conversion circuit having a flying capacitor and method for precharging the same are provided. The multilevel conversion circuit includes: a first bridge arm including a plurality of switches connected in series; a second bridge arm including a plurality of switches connected in series and a flying capacitor group, midpoints of the two bridge arms connected to a power supply and an inductor to form a series branch; a DC bus capacitor to which the two bridge arms are connected in parallel; a first voltage clamping module connected between a first end of the flying capacitor group and a first end of the DC bus capacitor; and a second voltage clamping module connected between a second end of the flying capacitor group and a second end of the DC bus capacitor.

A multilevel conversion circuit having a flying capacitor is provided, including: a first bridge arm; a second bridge arm including a flying capacitor, the midpoints of the second and first bridge arms connected to a series branch defined by a first current limiting circuit, a power supply and an inductor; a DC bus capacitor connected in parallel to the first and second bridge arms; a rectifier circuit having an input end coupled to the power supply and an output end connected to a first auxiliary power supply; and a controller coupled to the first auxiliary power supply and the plurality of switches of the second bridge arm to control corresponding switches of the second bridge arm, the power supply charges the flying capacitor through the corresponding switches of the first and second bridge arms and the first current limiting circuit.

Methods and apparatus for active EMI cancellation in a switch mode power supply are provided herein. For example, an apparatus comprises an active EMI cancellation circuit coupled to a switch mode power supply circuit comprising an isolation transformer, wherein the active EMI cancellation circuit is positioned such that current flow through an EMI coupling capacitor substantially matches displacement current flow through a primary-to-secondary interwinding capacitance of the isolation transformer.

A circuit for use in a switched mode power supply includes a dual-boost power-factor correction converter having an active rectifier stage with first and second rectifier transistors and first and second boost stages each with an inductor and transistor. An active rectifier controller circuit generates control signals for driving the rectifier transistors, respectively, on and off in accordance with an AC input voltage. A PFC controller circuit generates a pulse-width-modulated (PWM) control signal that is based on an output voltage of the boost stages and which is further based on a current sense signal representing the current passing through the active rectifier stage. A logic circuit generates a control signal for the transistor of the first boost stage and a control signal for the transistor of the second boost stage, based on the PWM control signal and at least one of the control signals for the rectifier transistors.

The present disclosure provides a power conversion device. The power conversion device includes the multi-level power factor correction circuit, the at least one output capacitor, the at least one input capacitor group, the first resonant conversion circuit and the second resonant conversion circuit. The at least one input capacitor group includes the first input capacitor and the second input capacitor. The at least one output capacitor is connected to an output part of the multi-level power factor correction circuit. The at least one input capacitor group is connected to the at least one output capacitor in parallel. The second input capacitor is connected to the first input capacitor in series. The input part of the first resonant conversion circuit is connected to first input capacitor in parallel. The input part of the second resonant conversion circuit is connected to the second input capacitor in parallel.