A balun includes an unbalanced terminal; balanced terminals; first and second main lines; and first and second sub-lines. The first main line has an end connected to the unbalanced terminal. The second main line has an end connected to the first main line and an end that is open. Each of the first and the second sub-lines is connected between the balanced terminal and a reference potential, respectively. The second sub-line includes a first partial line connected to the balanced terminal, and a second partial line connected between the first partial line and the reference potential. The second main line includes a third partial line connected to the first main line, and a fourth partial line connected to the third partial line. The distance between the first partial line and the third partial line is shorter than the distance between the second partial line and the fourth partial line.

An electronic device has a substrate and first and second metallization levels with a resonant circuit. The first metallization level has a first dielectric layer on a side of the substrate, and a first metal layer on the first dielectric layer. The second metallization level has a second dielectric layer on the first dielectric layer and the first metal layer, and a second metal layer on the second dielectric layer. The electronic device includes a first plate in the first metal layer, and a second plate spaced apart from the first plate in the second metal layer to form a capacitor. The electronic device includes a winding in one of the first or second metal layers and coupled to one of the first or second plates in a resonant circuit.

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.

Micro-isolators exhibiting enhanced isolation breakdown voltage are described. The micro-isolators may include an electrically floating ring surrounding one of the isolator elements of the micro-isolator. The isolator elements may be capacitor plates or coils. The electrically floating ring surrounding one of the isolator elements may reduce the electric field at the outer edge of the isolator element, thereby enhancing the isolation breakdown voltage.

The present disclosure provides a signal convertor, which includes a circuit board, a plurality of isolation transformers, a capacitor, a signal-converting module, an electrical connection interface and a plugging interface. The isolation transformers, the capacitor, the signal-converting module are disposed on the circuit board. The signal-converting module is for converting a plugging signal received from the plugging interface into an electrical signal and transferring the electrical signal to the isolation transformers, or for converting the electrical signal received from the isolation transformers into the plugging signal and transferring the plugging signal to the plugging interface.

The present disclosure provides a signal convertor, which includes a circuit board, a plurality of isolation transformers, a capacitor, a signal-converting module, an electrical connection interface and a plugging interface. The isolation transformers, the capacitor, the signal-converting module are disposed on the circuit board. The signal-converting module is for converting a plugging signal received from the plugging interface into an electrical signal and transferring the electrical signal to the isolation transformers, or for converting the electrical signal received from the isolation transformers into the plugging signal and transferring the plugging signal to the plugging interface.

A transformer connection method for a transformer includes a first high-frequency terminal configured as a first end of a first plate winding, a second high-frequency terminal configured as a first end of a second plate winding, and a direct current terminal connected to a second end of the first plate winding and a second end of the second plate winding. The transformer connection method comprises connecting the first high-frequency terminal and the second high-frequency terminal to a circuit board to cause the first high-frequency terminal and the second high-frequency terminal to be upright from a surface of the circuit board; and connecting the direct current terminal to a component or to the circuit board connecting with the component, the direct current terminal extending from a portion between the transformer and the circuit board to an outside.

A LNA comprises an input, a transformer structure and a first transistor and a second transistor, each having gate, source, and drain terminals. The transformer structure has a first winding pair, a second winding pair and a third winding pair. Each winding of the first winding pair connects to the input node and one source terminals of the transistors. The second winding pair is proximate the first winding pair. The second winding pair connects to a ground node and the transistor source terminals. The third winding pair is proximate the first winding pair and it connects to a bias signal source and a gate terminal of the transistors. An output connects to the transistor drain terminals. The windings of the first and second winding pairs are offset and rotated 180 degrees with respect to the other winding in the pair. The third winding pair performs a Gm boost function.

The invention relates to a circuit arrangement for combined protection of a load from temporary and transient overvoltages with emergency operation of the load in the presence of a temporary overvoltage and with integrated follow current limitation, wherein a first surge arrester, in particular a spark gap or a varistor, is provided between network-side input terminals and a second surge arrester, in particular a varistor, is provided between load-side output terminals for follow current limitation. According to the invention, at least one controlled semiconductor switch is provided in each case in the series branch between the input terminal and the output terminal and in the output-side parallel branch, wherein a mechanical switch and a series capacitance are connected in parallel with the semiconductor switch in the series branch. Furthermore, the semiconductor switch in the parallel branch is part of a series circuit comprising a parallel circuit comprising a second surge arrester and a parallel capacitance. A series inductance is provided in the series branch between the input terminal and the parallel circuit comprising the series capacitance, the controlled semiconductor switch and the mechanical switch. A microcontroller for controlling the semiconductor switches is also present, wherein the microcontroller is connected to a current detector in the series branch.