公开(公告)号：US20120014148A1

公开(公告)日：2012-01-19

申请号：US13184788

申请日：2011-07-18

申请人： Qian Li ,  Fred C. Lee ,  Ming Xu ,  Chuanyun Wang

发明人： Qian Li ,  Fred C. Lee ,  Ming Xu ,  Chuanyun Wang

IPC分类号： H02M1/00

CPC分类号： H02M1/4216 ,  H02M1/4225 ,  H02M1/44 ,  H02M2001/0032 ,  H02M2003/1586 ,  Y02B70/126 ,  Y02B70/16 ,  Y02P80/112

摘要： Light load efficiency of a power factor correction circuit is improved by adaptive on-time control and providing for selection between a continuous conduction mode and a discontinuous conduction mode wherein the discontinuous conduction mode increases time between switching pulses controlling connection of a cyclically varying voltage to a filter/inductor that delivers a desired DC voltage and thus can greatly reduce the switching frequency at light loads where switching frequency related losses dominate efficiency. The mode for controlling switching is preferably selected for each switching pulse within a half cycle of the cyclically varying input voltage. A multi-phase embodiment allows cancellation of EMI noise at harmonics of the switching frequency and adaptive change of phase angle allows for cancellation of dominant higher order harmonics as switching frequency is reduced.

摘要翻译： 通过自适应导通时间控制来提高功率因数校正电路的轻负载效率，并提供连续导通模式和不连续导通模式之间的选择，其中不连续导通模式增加了控制周期性变化的电压连接到开关脉冲之间的时间 滤波器/电感器提供所需的直流电压，因此可以大大降低开关频率相关损耗占优势的轻负载时的开关频率。 优选地，在循环变化的输入电压的半周期内针对每个开关脉冲选择用于控制切换的模式。 多相实施例允许在开关频率的谐波处消除EMI噪声，并且由于开关频率降低，相位角的自适应变化允许抵消主要高阶谐波。

公开(公告)号：US07872886B2

公开(公告)日：2011-01-18

申请号：US12034229

申请日：2008-02-20

申请人： Ming Xu ,  Julu Sun ,  Ya Liu ,  Fred C. Lee

发明人： Ming Xu ,  Julu Sun ,  Ya Liu ,  Fred C. Lee

IPC分类号： H02M7/00

CPC分类号： H02M3/1584 ,  H02M2001/0074 ,  Y02B70/1425 ,  Y10T307/685

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.

摘要翻译： 改进的调节和瞬态响应由电源架构提供，其提供并联的不稳压和稳压电压转换器，但是从串联连接的单独电源导出输入功率，其中调节和未调节的分支各自提供基本上固定的和恒定的输出电流比例。 输入电源的串联连接可以提供进一步的反馈机制，以及增强整体性能的调节反馈。 作为本发明的完善特征，可以在非调节支路中使用以交错方式切换的无电感谐振转换器，同时基本上消除其特征性的大输出电压纹波。

公开(公告)号：US07821375B2

公开(公告)日：2010-10-26

申请号：US11668229

申请日：2007-01-29

申请人： Yan Dong ,  Ming Xu ,  Fred C. Lee

发明人： Yan Dong ,  Ming Xu ,  Fred C. Lee

IPC分类号： H01F27/28 ,  H01F5/00

CPC分类号： H02M3/1584 ,  H01F17/0006 ,  H01F27/255 ,  H01F37/00

摘要： A multiple phase buck converter or boost converter, or buck-boost converter has an inductor in each phase. The inductors are inversely coupled. In a first embodiment, the converter includes a toroidal magnetic core with inductors extending under and over opposite sides of the toroidal magnetic core. The coupled inductors are thereby inversely coupled and have a relatively low ohmic resistance. In a second embodiment, the converter comprises a ladder-shaped magnetic core (i.e. having parallel sides, and connecting rungs). In this case, the inductors extend under the sides, and over the rungs. Each inductor is disposed over a separate rung. The ladder-shaped magnetic core is preferably disposed flat on a circuit board. Inverse coupling and low ohmic resistance are also provided in the second embodiment having the ladder structure.

公开(公告)号：US07602154B2

公开(公告)日：2009-10-13

申请号：US11749405

申请日：2007-05-16

申请人： Dianbo Fu ,  Fred C. Lee

发明人： Dianbo Fu ,  Fred C. Lee

IPC分类号： H02M3/335

CPC分类号： H02M3/33592 ,  H02M1/08 ,  Y02B70/1433 ,  Y02B70/1475

摘要： Phase compensation of a voltage appearing on physical terminals of a synchronous rectifier switching element such as a MOSFET is used to substantially eliminate effects of package inductance of the synchronous rectifier and thus approximate the actual voltage across the circuit element providing synchronous rectification in, for example, a switching power converter. By doing so and using the phase compensated signal to control the synchronous rectifier, switching time may be more suitably controlled to improve efficiency of the synchronous rectifier by substantially eliminating body diode conduction and body diode reverse recovery effects.

摘要翻译： 使用同步整流器开关元件（例如MOSFET）的出现在物理端子上的电压的相位补偿基本上消除了同步整流器的封装电感的影响，并因此近似于电路元件两端的实际电压，提供同步整流，例如， 开关电源转换器。 通过这样做并且使用相位补偿信号来控制同步整流器，可以更适当地控制开关时间，以通过基本上消除体二极管导通和体二极管反向恢复效应来提高同步整流器的效率。

公开(公告)号：US07583065B2

公开(公告)日：2009-09-01

申请号：US12401815

申请日：2009-03-11

申请人： Ming Xu ,  Yuancheng Ren ,  Fred C. Lee ,  Andrew P. Schmit

发明人： Ming Xu ,  Yuancheng Ren ,  Fred C. Lee ,  Andrew P. Schmit

IPC分类号： G05F1/614 ,  G05F1/563

CPC分类号： H02M3/158 ,  H02M2001/0045

摘要： An active linear regulator circuit in parallel with a filter capacitor of a switching voltage regulator injects current to a load only when the switching regulator and capacitor cannot supply adequate current to follow high frequency load transients in a manner which is compatible with adaptive voltage positioning (AVP) requirements. control of current injection and determination of the insufficiency of current from the switching regulator and capacitors is achieved by impedance matching of the linear regulator to the switching regulator. The linear regulator thus operates at relatively low current and duty cycle to limit power dissipation therein. By matching impedances and increasing the bandwidth of the switching regulator, filter capacitor requirements can be reduced to the point of being met entirely by packaging and/or on-die capacitors which may be placed close to or at the point of load to reduce parasitic inductance, as can the linear regulator.

公开(公告)号：US20080239771A1

公开(公告)日：2008-10-02

申请号：US11834281

申请日：2007-08-06

申请人： Chuanyun Wang ,  Ming Xu ,  Fred C. Lee

发明人： Chuanyun Wang ,  Ming Xu ,  Fred C. Lee

IPC分类号： H02M1/12

CPC分类号： H02M1/12 ,  H02M1/42 ,  H02M3/1584 ,  H02M2003/1586 ,  Y02B70/12

摘要： In a power converter having m=two or more channels of power factor correction (PFC) circuits connected in parallel and an electromagnetic interference (EMI) filter connected in series therewith, phase shifts in switching between the respective PFC channels can allow increase of EMI filter corner frequency allowing reduction of size and cost of the EMI filter at some switching frequencies. Asymmetrical phase shifts (other than 360°/m) such as 360°/2m and other phase shifts and variations in m allow increase of EMI filter corner frequency at switching frequencies where symmetrical, 360°/m phase shifts provide no benefit to EMI filter design by providing cancellation or partial cancellation of different harmonics of the switching noise; which cancellation may be arranged to be complementary to the EMI filter function at more than one peak of the noise spectrum. (Such asymmetrical phase shifts do not significantly increase ripple and consequent switching noise). Alteration of m and corresponding alteration of phase shift may be performed adaptively for purposes of improving efficiency at light loads and the like.

摘要翻译： 在具有并联连接的m = 2个或更多个功率因数校正（PFC）电路的通道和与其串联连接的电磁干扰（EMI））滤波器的功率转换器中，在相应PFC通道之间的切换中的相移可允许增加EMI滤波器 转角频率允许在某些开关频率下降低EMI滤波器的尺寸和成本。 360°/ 2m以外的不对称相移（360°/ 2m）和其它相移以及m的变化允许在对称的开关频率下增加EMI滤波器转角频率，360°/ m相移对EMI滤波器无益 通过提供消除或部分消除开关噪声的不同谐波的设计; 该消除可以被布置为在噪声谱的多于一个峰值处与EMI滤波器功能互补。 （这种非对称相移不会显着增加纹波和随之而来的开关噪声）。 m的改变和相移的相应改变可以自适应地进行，以提高轻负载等的效率。

公开(公告)号：US07196914B2

公开(公告)日：2007-03-27

申请号：US10992227

申请日：2004-11-19

申请人： Yuancheng Ren ,  Fred C. Lee ,  Ming Xu

发明人： Yuancheng Ren ,  Fred C. Lee ,  Ming Xu

IPC分类号： H02M3/335

CPC分类号： H02M3/33592 ,  H02M3/33569 ,  Y02B70/1433 ,  Y02B70/1475

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益处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。

公开(公告)号：US07071660B2

公开(公告)日：2006-07-04

申请号：US11018920

申请日：2004-12-22

申请人： Ming Xu ,  Jinghai Zhou ,  Yuancheng Ren ,  Fred C. Lee ,  Jia Wei

发明人： Ming Xu ,  Jinghai Zhou ,  Yuancheng Ren ,  Fred C. Lee ,  Jia Wei

IPC分类号： H02M3/158

CPC分类号： H02M3/156 ,  H02M2001/0019 ,  H02M2001/0032 ,  H02M2001/007 ,  Y02B70/16

摘要： A two-stage power converter that dynamically adjusts to output current requirements includes a first stage regulator that provides power to a second stage regulator. The first stage can be a buck converter, and the second stage can be a multiple-phase buck converter. The output voltage of the first stage (intermediate bus voltage Vbus) is varied according to the load current to optimize conversion efficiency. To provide maximum efficiency, the Vbus voltage is increased as load current increases. The Vbus voltage provided by the first stage can be varied by duty cycle or operating frequency control. In another embodiment, the switching frequency of the second stage is varied as output current changes so that output current ripple is held constant. In an embodiment employing a multiple-phase buck converter in the second stage, the number of operating phases are varied as output current changes.

摘要翻译： 动态调节输出电流要求的两级功率转换器包括为第二级调节器提供电源的第一级稳压器。 第一级可以是降压转换器，第二级可以是多相降压转换器。 第一级（中间总线电压Vbus）的输出电压根据负载电流而变化，以优化转换效率。 为了提供最大的效率，Vbus电压随着负载电流的增加而增加。 第一级提供的Vbus电压可以通过占空比或工作频率控制来改变。 在另一个实施例中，当输出电流改变时，第二级的开关频率变化，使得输出电流纹波保持恒定。 在第二级采用多相降压转换器的实施例中，随着输出电流的变化，工作阶段的数量变化。

公开(公告)号：US06989997B2

公开(公告)日：2006-01-24

申请号：US10603097

申请日：2003-06-25

申请人： Ming Xu ,  Fred C. Lee

发明人： Ming Xu ,  Fred C. Lee

IPC分类号： H02M3/335

CPC分类号： H02M3/158 ,  H02M3/33576 ,  Y02B70/1425 ,  Y02B70/1433

摘要： Buck converters having a resonant inductor Lr, resonant capacitor Cr, and synchronous switch Q3 that together provide reduced switching loss and soft switching. In operation, the resonant inductor Lr is charged during a time period A. Then, Lr is freewheeling and provides current to an output inductor Lo. Then, Q3 is turned OFF, and energy from the resonant inductor Lr charges the resonant capacitor Cr. Finally, energy from the resonant capacitor Cr is provided to the output inductor and load. The output power can be adjusted by phase control of the operation of switch Q3. In alternative embodiments, the circuit has a pair of coupled inductors L1 L2 or an isolation transformer 40. The coupled inductors have a polarity selected so that the output voltage is reduced, thereby allowing top switch Q1 to have a greater duty cycle. These circuits feature no body diode loss in the switch Q3.

摘要翻译： 具有谐振电感器Lr，谐振电容器Cr和同步开关Q 3的降压转换器一起提供降低的开关损耗和软开关。 在运行中，谐振电感器Lr在时间段A内被充电。然后，Lr是续流并且向输出电感器Lo提供电流。 然后，Q 3截止，来自谐振电感器Lr的能量对谐振电容器Cr充电。 最后，将谐振电容器Cr的能量提供给输出电感器和负载。 可以通过开关Q 3的操作的相位控制来调节输出功率。 在替代实施例中，电路具有一对耦合电感器L 1 L 2或隔离变压器40。 耦合电感器具有选择的极性，使得输出电压降低，从而允许顶部开关Q1具有更大的占空比。 这些电路在开关Q 3中没有体二极管损耗。

公开(公告)号：US5361014A

公开(公告)日：1994-11-01

申请号：US150706

申请日：1993-11-10

申请人： James A. Antone ,  Fred C. Lee ,  Wojciech A. Tabisz

发明人： James A. Antone ,  Fred C. Lee ,  Wojciech A. Tabisz

IPC分类号： F02D41/20 ,  H01L41/04 ,  H02N2/06 ,  H01L41/08 ,  F02M51/00

CPC分类号： F02D41/2096 ,  H02N2/067

摘要： An apparatus that drives a piezoelectric actuator in response to charging and discharging command signals is disclosed. The apparatus includes an energy source that supplies electrical energy to the piezoelectric actuator. A charging circuit includes: a charging transistor connected to the energy source to control the amount energy supplied to the piezoelectric actuator, a charging inductor connected to the charging transistor to limit the rate of change of energy supplied to the piezoelectric actuator, and a charging thyristor disposed between the charging circuit and the piezoelectric actuator. A selecting circuit receives the charging command signal and responsively biases the charging thyristor ON to connect the piezoelectric actuator to the charging circuit. A comparator determines the magnitude of voltage applied to the piezoelectric actuator. A control circuit receives the charging command signal, and responsively biases the charging transistor alternately ON and OFF to control the amount of energy supplied to the piezoelectric actuator in response to the piezoelectric actuator voltage being less than an upper desired voltage value. Finally, the selecting circuit biases the charging thyristor OFF to disconnect the piezoelectric actuator from the charging circuit in response to the piezoelectric actuator voltage being greater than or equal to the upper desired voltage value.

摘要翻译： 公开了一种响应于充电和放电命令信号驱动压电致动器的装置。 该装置包括向压电致动器提供电能的能量源。 充电电路包括：连接到能量源的充电晶体管，以控制提供给压电致动器的能量;连接到充电晶体管的充电电感器，以限制供应给压电致动器的能量的变化率;以及充电晶闸管 设置在充电电路和压电致动器之间。 选择电路接收充电命令信号并响应于偏置充电晶闸管导通以将压电致动器连接到充电电路。 比较器确定施加到压电致动器的电压的大小。 控制电路接收充电命令信号，并且响应于交替地开启和关闭充电晶体管而响应于压电致动器电压小于上限期望电压值来控制提供给压电致动器的能量的量。 最后，选择电路将充电晶闸管偏置，以响应于压电致动器电压大于或等于上限期望电压值，将压电致动器与充电电路断开。