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1. 发明授权

US08780590B2 Output current estimation for an isolated flyback converter with variable switching frequency control and duty cycle adjustment for both PWM and PFM modes 有权
标题翻译：用于PWM和PFM模式的具有可变开关频率控制和占空比调整的隔离反激式转换器的输出电流估计
公开(公告)号：US08780590B2
公开(公告)日：2014-07-15
申请号：US13462986
申请日：2012-05-03
申请人： Wai Kit (Victor) So , Hing Kit Kwan , Chik Wai (David) Ng , Po Wah (Patrick) Chang
发明人： Wai Kit (Victor) So , Hing Kit Kwan , Chik Wai (David) Ng , Po Wah (Patrick) Chang
IPC分类号： H02M3/335
CPC分类号： H02M3/33507 , H02M2001/0009
摘要： A fly-back power converter has a current-estimating control loop that senses the primary output current in a transformer to control the secondary output. A primary-side control circuit switches primary current through the transformer on and off. A discharge time when a secondary current through an auxiliary winding of the transformer is flowing is generated by sampling a voltage divider on an auxiliary loop for a knee-point. A normalized duty cycle is calculated by multiplying the discharge time by a current that is proportional to the switching frequency and comparing to a sawtooth signal having the switching frequency. The peak of a primary-side voltage is sensed from the primary current loop and converted to a current and multiplied by the normalized duty cycle to generate an estimated current. An error amp compares the estimated current to a reference to adjust the oscillator frequency and peak current to control primary switching.
摘要翻译：回扫功率转换器具有电流估算控制回路，其感测变压器中的主要输出电流以控制次级输出。初级侧控制电路通过变压器开启和关闭一次电流。通过变压器的辅助绕组的二次电流流过的放电时间是通过对用于拐点的辅助回路上的分压器进行采样而产生的。通过将放电时间乘以与开关频率成比例的电流并与具有开关频率的锯齿波信号进行比较来计算归一化占空比。初级侧电压的峰值从初级电流回路感测并转换为电流并乘以归一化的占空比以产生估计电流。误差放大器将估计电流与参考值进行比较，以调整振荡器频率和峰值电流以控制主开关。

2. 发明授权

US08188798B1 Programmable electro-magnetic-interference (EMI) reduction with enhanced noise immunity and process tolerance 有权
标题翻译：可编程电磁干扰（EMI）降低，增强抗噪声和工艺容差
公开(公告)号：US08188798B1
公开(公告)日：2012-05-29
申请号：US12948896
申请日：2010-11-18
申请人： Chi Tak (Gerry) Leung , Chik Wai (David) Ng , Hing Kit Kwan , Wai Kit (Victor) So , Po Wah (Patrick) Chang , Wing Cheong Mak , Kwok Kuen (David) Kwong
发明人： Chi Tak (Gerry) Leung , Chik Wai (David) Ng , Hing Kit Kwan , Wai Kit (Victor) So , Po Wah (Patrick) Chang , Wing Cheong Mak , Kwok Kuen (David) Kwong
IPC分类号： H03B29/00 , H03K3/26
CPC分类号： H03L7/08
摘要： A frequency dithering circuit reduces emissions that cause Electro-Magnetic Interference (EMI) by spreading the spectrum of a clock. The clock sequences a counter that drives a digital count value to a digital-to-analog converter (DAC). The DAC outputs a sawtooth wave with a wide voltage swing. A subtractor scales down the voltage swing to produce a reduced-swing sawtooth wave which is used as an upper limit voltage. Comparators trigger a set-reset latch to toggle the clock when current pumps charge and discharge a capacitor beyond voltage limits. Since the upper limit voltage is the reduced sawtooth wave from the subtractor, the amount of time to charge the capacitor varies, dithering the period of the clock. The degree of dithering can be adjusted by programming the feedback resistance in the subtractor. The subtractor reduces the sensitivity of dithering to errors in the DAC, allowing for an inexpensive, less precise DAC.
摘要翻译：频率抖动电路通过扩展时钟的频谱来减少引起电磁干扰（EMI）的辐射。该时钟是将数字计数值驱动到数模转换器（DAC）的计数器。 DAC输出宽电压摆幅的锯齿波。减法器缩小电压摆幅，产生用作上限电压的减小摆动锯齿波。当电流泵对电容器充电和放电超过电压限制时，比较器触发设置复位锁存器来切换时钟。由于上限电压是来自减法器的减少的锯齿波，所以对电容器充电的时间量变化，使时钟的周期抖动。可以通过对减法器中的反馈电阻进行编程来调整抖动度。减法器可降低抖动对DAC误差的灵敏度，从而实现廉价，精度更低的DAC。

3. 发明授权

US08300431B2 Constant-current control module using inverter filter multiplier for off-line current-mode primary-side sense isolated flyback converter 有权
标题翻译：恒流控制模块采用变频器滤波器，用于离线电流模式初级侧感测隔离反激式转换器
公开(公告)号：US08300431B2
公开(公告)日：2012-10-30
申请号：US12718707
申请日：2010-03-05
申请人： Chik Wai (David) Ng , Hing Kit Kwan , Po Wah (Patrick) Chang , Wai Kit (Victor) So , Kwok Kuen (David) Kwong
发明人： Chik Wai (David) Ng , Hing Kit Kwan , Po Wah (Patrick) Chang , Wai Kit (Victor) So , Kwok Kuen (David) Kwong
IPC分类号： H02M3/335
CPC分类号： H02M3/335
摘要： A fly-back AC-DC power converter has a constant-current control loop that senses the primary output current in a transformer to control the secondary output without an expensive opto-isolator. A primary-side control circuit can use either a Quasi-Resonant (QR) or a Pulse-Width-Modulation (PWM) control loop to switch primary current through the transformer on and off. A feedback voltage is compared to a primary-side voltage sensed from the primary current loop to turn the switch on and off. A multiplier loop generates the feedback voltage using a multiplier. A level-shift inverter and a low-pass filter act as the multiplier by multiplying an off duty cycle of the switch by the feedback voltage to generate a filtered voltage. A high-gain error amp compares the filtered voltage to a reference voltage to generate the feedback voltage. The multiplier produces a simple relationship between the secondary current and the reference voltage, yielding simplified current control.
摘要翻译：回扫AC-DC电力转换器具有恒定电流控制回路，其感测变压器中的主要输出电流，以在没有昂贵的光隔离器的情况下控制次级输出。初级侧控制电路可以使用准谐振（QR）或脉冲宽度调制（PWM）控制回路来切换通过变压器的一次电流的开和关。将反馈电压与从初级电流回路感测的初级侧电压进行比较，以打开和关闭开关。乘法器环路使用乘法器产生反馈电压。电平移位反相器和低通滤波器通过将开关的占空比乘以反馈电压作为乘法器，以产生滤波电压。高增益误差放大器将滤波电压与参考电压进行比较，以产生反馈电压。乘法器产生二次电流和参考电压之间的简单关系，产生简化的电流控制。

4. 发明申请

US20110216559A1 Constant-Current Control Module using Inverter Filter Multiplier for Off-line Current-Mode Primary-Side Sense Isolated Flyback Converter 有权
标题翻译：恒流控制模块使用变频滤波乘法器进行离线电流模式初级侧检测隔离反激式转换器
公开(公告)号：US20110216559A1
公开(公告)日：2011-09-08
申请号：US12718707
申请日：2010-03-05
申请人： Chik Wai (David) Ng , Hing Kit Kwan , Po Wah Chang , Wai Kit (Victor) So , Kwok Kuen Kwong
发明人： Chik Wai (David) Ng , Hing Kit Kwan , Po Wah Chang , Wai Kit (Victor) So , Kwok Kuen Kwong
IPC分类号： H02M3/335
CPC分类号： H02M3/335
摘要： A fly-back AC-DC power converter has a constant-current control loop that senses the primary output current in a transformer to control the secondary output without an expensive opto-isolator. A primary-side control circuit can use either a Quasi-Resonant (QR) or a Pulse-Width-Modulation (PWM) control loop to switch primary current through the transformer on and off. A feedback voltage is compared to a primary-side voltage sensed from the primary current loop to turn the switch on and off. A multiplier loop generates the feedback voltage using a multiplier. A level-shift inverter and a low-pass filter act as the multiplier by multiplying an off duty cycle of the switch by the feedback voltage to generate a filtered voltage. A high-gain error amp compares the filtered voltage to a reference voltage to generate the feedback voltage. The multiplier produces a simple relationship between the secondary current and the reference voltage, yielding simplified current control.
摘要翻译：回扫AC-DC电力转换器具有恒定电流控制回路，其感测变压器中的主要输出电流，以在没有昂贵的光隔离器的情况下控制次级输出。初级侧控制电路可以使用准谐振（QR）或脉冲宽度调制（PWM）控制回路来切换通过变压器的一次电流的开和关。将反馈电压与从初级电流回路感测的初级侧电压进行比较，以打开和关闭开关。乘法器环路使用乘法器产生反馈电压。电平移位反相器和低通滤波器通过将开关的占空比乘以反馈电压作为乘法器，以产生滤波电压。高增益误差放大器将滤波电压与参考电压进行比较，以产生反馈电压。乘法器产生二次电流和参考电压之间的简单关系，产生简化的电流控制。

5. 发明申请

US20100164625A1 Slew-Rate-Enhanced Error Amp with Adaptive Transconductance and Single Dominant Pole Shared by Main and Auxiliary Amps 有权
标题翻译：具有自适应跨导和主主导极共同的主要和辅助放大器的转换率增益误差放大器
公开(公告)号：US20100164625A1
公开(公告)日：2010-07-01
申请号：US12345862
申请日：2008-12-30
申请人： Yat To (William) Wong , Chik Wai (David) Ng , Ho Ming (Karen) Wan , Kam Chuen Wan , Kwok Kuen (David) Kwong
发明人： Yat To (William) Wong , Chik Wai (David) Ng , Ho Ming (Karen) Wan , Kam Chuen Wan , Kwok Kuen (David) Kwong
IPC分类号： H03F3/45
CPC分类号： H03F3/45197 , H03F3/3023 , H03F3/45475 , H03F2203/45248 , H03F2203/45646 , H03F2203/45652 , H03F2203/45678
摘要： An error amplifier can be used to control a power regulator transistor. The error amplifier has a main amplifier, a pull-up auxiliary amplifier, and a pull-down auxiliary amplifier that all drive an output. A compensating capacitor on the output sets a single dominant pole for all amplifiers, increasing stability. High slew rates are provided by increased slew current from the auxiliary amplifiers that turn on when the differential input has an absolute voltage difference larger than an intentional offset. The intentional offset is introduced into the auxiliary amplifiers by adjusting a p-channel to n-channel transistor ratio in a leg of the auxiliary amplifiers. A source degenerated resistor in the main amplifier reduces supply headroom and increases linearity by connecting sources of two differential transistors that receive the differential input. Cascode transistors increase gain and output impedance. Reliability is increased as no positive feedback is used in the amplifiers.
摘要翻译：误差放大器可用于控制功率调节晶体管。误差放大器具有主放大器，上拉辅助放大器和全部驱动输出的下拉辅助放大器。输出上的补偿电容为所有放大器设置单个主极，从而提高稳定性。当差分输入具有大于有意偏移的绝对电压差时，来自辅助放大器的增加的转换电流提供高转换速率。通过调整辅助放大器的一个支路中的p沟道至n沟道晶体管比，将有意的偏移引入辅助放大器。主放大器中的源极退化电阻通过连接接收差分输入的两个差分晶体管的源极减小了供电余量并增加了线性度。串联晶体管增加了增益和输出阻抗。在放大器中没有使用正反馈的情况下，可靠性提高。

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