摘要:
A voltage converter uses a component such as a JFET or four-terminal power MOSFET having no body diode and exhibiting no body diode conduction characteristic as a synchronous rectifier to reduce switching losses and body diode conduction losses and to support high frequency switching so that use of smaller components and higher current densities can be achieved. These effects are enhanced by a self-driven circuit utilizing positive feedback to enhance switching speed and reduce switching losses which increase with switching frequency.
摘要:
A voltage converter uses a component such as a JFET or four-terminal power MOSFET having no body diode and exhibiting no body diode conduction characteristic as a synchronous rectifier to reduce switching losses and body diode conduction losses and to support high frequency switching so that use of smaller components and higher current densities can be achieved. These effects are enhanced by a self-driven circuit utilizing positive feedback to enhance switching speed and reduce switching losses which increase with switching frequency.
摘要:
Power converters having reduced body diode conduction loss, reduced reverse recovery loss and lower switching noise, among other benefits, have a resonant capacitor Cr connected across an unfiltered output. The resonant capacitor Cr resonates with the leakage inductance Lk of the transformer. The resonant capacitor and leakage inductance are selected such that ½ a LC resonance period is equal to an ON time of each secondary switch S1 S2. The resonance provides zero current switching for secondary switches S1 S2, eliminates zero body diode conduction during dead times, and eliminates reverse recovery losses in the secondary switches. The present invention is applicable to many different circuit topologies such as full bridge, active clamp forward, push-pull forward, and center-tap secondary. The present converters provide high energy conversion efficiency and high frequency operation.
摘要翻译:具有降低的体二极管导通损耗,降低的反向恢复损耗和较低开关噪声以及其他优点的功率转换器具有连接在未滤波输出端的谐振电容器Cr。 谐振电容器Cr与变压器的漏电感Lk共振。 选择谐振电容器和漏电感,使得LC谐振周期的1/2相当于每个次级开关S 1 S 2的导通时间。谐振为次级开关S 1 S 2提供零电流开关,消除零体二极管导通 并且消除了次级开关中的反向恢复损耗。 本发明可应用于许多不同的电路拓扑,例如全桥,有源钳前进,推挽前进和中心抽头次级。 本转换器提供高能量转换效率和高频操作。
摘要:
A current-input-type parallel resonant DC/DC converter and a method thereof are provided. The converter includes an inverter-circuit for inverting/converting an input DC current into a positive-and-negative alternating square-wave-current, a resonant-network for converting the square-wave-current into a sine-voltage, a transformer for realizing the isolation of the power transmission, a full-wave rectifier-circuit for rectifying the sine-voltage, and an output-filter-circuit for producing a DC output-voltage. The inverter-circuit is connected to both terminals of a primary-winding of the transformer through the resonant-network connected in series with the inverter-circuit, a common-polarity terminal of a first-winding at a secondary side of the transformer and an opposite-polarity terminal of a second-winding at the secondary side of the transformer are respectively connected to an input of the full-wave rectifier-circuit, and an output of the full-wave rectifier-circuit and a center-trap terminal at the secondary side of the transformer are respectively connected to an input of the output-filter-circuit.
摘要:
A voltage converter having four switches Q1, Q2, Q3, Q4, connected in series and operated in pairs in a complementary fashion. An input voltage is provided across the four switches. A middle capacitor is connected in parallel with two middle switches Q2, Q3. Voltage output is provided across switches Q3 and Q4 (i.e. at a midpoint of the four switches). Series-connected output capacitors can be connected in parallel with the set of four switches. The middle capacitor alone or in combination with parallel connected capacitors, when connected to the input voltage or output terminals functions as a capacitive voltage divider for voltage conversion and/or regulation with extremely high efficiency and which can provide either step-down or step-up function. Also, an output inductor can be provided as a perfecting feature to further increase efficiency. Alternatively, two of the four switches can be replaced with rectifying diodes. Alternatively, the voltage converter has two or more sets of four switches connected in parallel. The two sets can be connected by resistor-capacitor ladder, or an inductor-capacitor ladder for charge/voltage sharing to reduce voltage ripple.
摘要:
A current-input-type parallel resonant DC/DC converter and a method thereof are provided. The converter includes an inverter-circuit for inverting/converting an input DC current into a positive-and-negative alternating square-wave-current, a resonant-network for converting the square-wave-current into a sine-voltage, a transformer for realizing the isolation of the power transmission, a full-wave rectifier-circuit for rectifying the sine-voltage, and an output-filter-circuit for producing a DC output-voltage. The inverter-circuit is connected to both terminals of a primary-winding of the transformer through the resonant-network connected in series with the inverter-circuit, a common-polarity terminal of a first-winding at a secondary side of the transformer and an opposite-polarity terminal of a second-winding at the secondary side of the transformer are respectively connected to an input of the full-wave rectifier-circuit, and an output of the full-wave rectifier-circuit and a center-tap terminal at the secondary side of the transformer are respectively connected to an input of the output-filter-circuit.
摘要:
A voltage converter having four switches Q1, Q2, Q3, Q4, connected in series and operated in pairs in a complementary fashion. An input voltage is provided across the four switches. A middle capacitor is connected in parallel with two middle switches Q2, Q3. Voltage output is provided across switches Q3 and Q4 (i.e. at a midpoint of the four switches). Series-connected output capacitors can be connected in parallel with the set of four switches. The middle capacitor alone or in combination with parallel connected capacitors, when connected to the input voltage or output terminals functions as a capacitive voltage divider for voltage conversion and/or regulation with extremely high efficiency and which can provide either step-down or step-up function. Also, an output inductor can be provided as a perfecting feature to further increase efficiency. Alternatively, two of the four switches can be replaced with rectifying diodes. Alternatively, the voltage converter has two or more sets of four switches connected in parallel. The two sets can be connected by resistor-capacitor ladder, or an inductor-capacitor ladder for charge/voltage sharing to reduce voltage ripple.
摘要:
Improved regulation and transient response are provided by a power supply architecture providing both unregulated and regulated voltage converters in parallel but deriving input power from separate power supplies connected in series wherein regulated and unregulated branches each provide a substantially fixed and constant proportion of the output current. The series connection of input power sources may provide a further feedback mechanism in addition to feedback for regulation which enhances overall performance. As a perfecting feature of the invention, inductor-less resonant converters which are switched in an interleaved fashion may be used in the unregulated branch while substantially cancelling the characteristic large output voltage ripple thereof.
摘要:
A single-stage AC/DC converter is provided, and which includes a power-frequency follow-current circuit, an isolated transmission circuit (ITC), a high-frequency chopper modulation circuit (HFCMC), a power-frequency and high-frequency AC rectifying-circuit and a filter-circuit. The input of the ITC is connected to the output of an external power-frequency power source, the current-modulating side of the ITC is connected to the input of the HFCMC, the output of the ITC is connected to the input of the power-frequency and high-frequency AC rectifying-circuit, the output of the HFCMC is connected to the input of the external power-frequency power source through the power-frequency follow-current connected in series with the HFCMC , and the output of the power-frequency and high-frequency AC rectifying circuit is connected to a load through the filter circuit connected in series with the power-frequency and high-frequency AC rectifying-circuit. The invention simplifies the rectifier part with higher transformation efficiency.
摘要:
Power converters having reduced body diode conduction loss, reduced reverse recovery loss and lower switching noise, among other benefits, have a resonant capacitor Cr connected across an unfiltered output. The resonant capacitor Cr resonates with the leakage inductance Lk of the transformer. The resonant capacitor and leakage inductance are selected such that ½ a LC resonance period is equal to an ON time of each secondary switch S1 S2. The resonance provides zero current switching for secondary switches S1 S2, eliminates zero body diode conduction during dead times, and eliminates reverse recovery losses in the secondary switches. The present invention is applicable to many different circuit topologies such as full bridge, active clamp forward, push-pull forward, and center-tap secondary. The present converters provide high energy conversion efficiency and high frequency operation.
摘要翻译:具有降低的体二极管导通损耗,降低的反向恢复损耗和较低开关噪声以及其他优点的功率转换器具有连接在未滤波输出端的谐振电容器Cr。 谐振电容器Cr与变压器的漏电感Lk共振。 谐振电容器和漏电感被选择为使得LC共振周期的1/2相当于每个次级开关S 1 S 2的导通时间。 谐振为次级开关S 1 S 2提供零电流开关,在死区时间消除零体二极管导通,并消除次级开关中的反向恢复损耗。 本发明可应用于许多不同的电路拓扑,例如全桥,有源钳前进,推挽前进和中心抽头次级。 本转换器提供高能量转换效率和高频操作。