Abstract:
Um bei einem Vollbrücken DC/DC-Wandler (1) mit Phasenlagensteuerung Schalten bei Nullspannung (ZVS) zu ermöglichen, ohne dafür eine zusätzliche Induktivität vorsehen zu müssen, ist vorgesehen, dass in der Übergangsphase von der aktiven in die passive Phase vor dem Umschalten in eine passive Phase der Vollbrücke (2) im sekundärseitigen Ausgangsgleichrichter (5) ein Kurzschluss erzeugt wird, der durch den entstehenden Kurzschlussstrom (i k ) über die Sekundärseite des Transformators (T) eine Erhöhung des Primärstromes (i p ) über die Primärseite des Transformators (T) bewirkt.
Abstract:
The embodiments herein describe a switched mode power converter. In particular, the embodiments herein disclose techniques for reducing power consumption of a synchronous rectifier controller of the switched mode power converter. The switched mode power converter includes a plurality of circuit components that control operation of a synchronous rectifier included in the switched mode power converter. One or more of the circuit components may be disabled to reduce power consumption.
Abstract:
An electrical circuit for providing electrical power for use in powering electronic devices is described herein. The electrical circuit includes a power converter circuit that is electrically coupled to an electrical power source for receiving alternating current (AC) input power from the electrical source and delivering direct current (DC) output power to an electronic device. The power converter circuit includes a transformer and a switching device coupled to a primary side of the transformer for delivering power from the electrical power source to a primary side of the transformer. A controller is coupled to a voltage sensor and the switching device for receiving the sensed voltage level from the voltage sensor and transmitting a control signal to the switching device to adjust the voltage level of power being delivered to the electronic device.
Abstract:
A voltage comparator includes an amplifier coupled to receive an input signal at an amplifier input and generate an output signal at an amplifier output in response to the input signal. The amplifier includes a current generation circuit coupled to generate a first current flowing through a first branch and a second current flowing through a second branch. A first transistor has a first terminal coupled to the amplifier input and a second terminal coupled to the first branch. A second transistor has a third terminal coupled to the second branch, a fourth terminal coupled to a reference voltage. A second control terminal of the second transistor is coupled to the first control terminal. An output circuit is coupled to the amplifier output to generate a comparator output signal in response to the output signal. The amplifier output is coupled to the second branch.
Abstract:
An energy efficient apparatus includes a switching device (12), a frequency dependent reactive device (14), and a control element (20) is provided. The switching device (12) is coupled to a source of electrical power (18) and includes a pair of transistors (40A,40B) and is adapted to receive a control signal and to produce an alternating current power signal. The frequency of the alternating current power signal is responsive to the control signal. The frequency dependent reactive device (14) is electrically coupled to the pair of transistors (40A,40B) for receiving the alternating current power signal and producing an output power signal. The frequency dependent reactive device (14) is chosen to achieve a desired voltage of the output power signal relative to the frequency of the alternating current power signal. The control element (20) senses an actual voltage of the direct current power signal and modifies the control signal delivered to achieve the desired voltage of the direct current power signal.
Abstract:
The invention relates to a DC-DC converter device (1) comprising a resonant circuit, a synchronous rectifier (3) and a digital signal processor (DSP). The DSP is comprising rectifier switch gate control terminals (GCsr1, GCsr2) for controlling the first and second rectifier switches (Sr1, Sr2) respectively, and resonant circuit switch gate control terminals (GCsdc1, GCsdc2) for controlling the first and second resonant circuit switches (Sdc1, Sdc2) respectively. A gate driver (GD) is connected between each rectifier switch gate control terminal (GCsr1, GCsr2) and the respective gate (Gsr1, Gsr2) of the first and second rectifier switches (Sr1, Sr2). A shutdown device (SD) is connected between each rectifier switch gate control terminal (GCsr1, GCsr2) and either an enable terminal of the corresponding gate driver (GD) or the gate (Gsr1, Gsr2) of the corresponding rectifier switch (Sr1, Sr2). The shutdown device (SD) is configured to control thegates (Gsr1, Gsr2) of the first and second rectifier switches(Sr1, Sr2) tostay low if the corresponding rectifier switch gate control terminal (GCsr1, GCsr2) was turned low when receiving the shutdown signal and to control the gates (Gsr1,Gsr2) of the first and secondrectifier switches (Sr1, Sr2) tostay high if the corresponding rectifier switch gate control terminal (GCsr1, GCsr2) was turned highwhen receiving the shutdown signal, and, when thefirst and/or second rectifier switch gate control terminal (GCsr1, GCsr2) is turned low by the digital signal processor (DSP), control the gate (Gsr1, Gsr2) of the corresponding rectifier switch (Sr1, Sr2) to stay low.