公开(公告)号：US08064231B2

公开(公告)日：2011-11-22

申请号：US12260585

申请日：2008-10-29

申请人： Shao-Hua Fang ,  Chao Chen ,  Jian-Hua Duan ,  Ya-Jiang Zhu

发明人： Shao-Hua Fang ,  Chao Chen ,  Jian-Hua Duan ,  Ya-Jiang Zhu

IPC分类号： H02M3/335

CPC分类号： H02M3/33507 ,  H02M1/32

摘要： A short circuit protection circuit for a pulse width modulation (PWM) unit which includes a PWM logic control circuit, an under voltage lookout (UVLO) circuit and an internal clock circuit; wherein the UVLO circuit detecting a bias power (Vcc) and delivering an UVLO signal when the bias power is judged excessively low, the PWM unit further comprising: a short circuit detector, a short circuit recovery circuit and a frequency multiplexer. The short circuit detector is to detect the UVLO signal and generate a short signal. The short circuit recovery circuit to set a pre-determined recovery time and generate a recovery signal when the pre-determined recovery time ends. The frequency multiplexer which is triggered by the short signal when the short circuit event occurs to change a switching frequency to a short PWM frequency, and triggered by the recovery signal to restore the switching frequency.

摘要翻译： 一种用于脉宽调制（PWM）单元的短路保护电路，其包括PWM逻辑控制电路，欠压监视（UVLO）电路和内部时钟电路; 其中所述UVLO电路检测偏置功率（Vcc）并且当所述偏置功率被判断为过低时传送UVLO信号，所述PWM单元还包括：短路检测器，短路恢复电路和频率复用器。 短路检测器是检测UVLO信号并产生一个短信号。 短路恢复电路设置预定的恢复时间，并在预定的恢复时间结束时产生恢复信号。 当发生短路事件时由短信号触发的频率复用器将开关频率改变为短的PWM频率，并由恢复信号触发以恢复开关频率。

公开(公告)号：US07864550B2

公开(公告)日：2011-01-04

申请号：US12265535

申请日：2008-11-05

申请人： Jian-Hua Duan ,  Rui-Xia Fei ,  Shao-Hua Fang ,  Qing-Hua Su

发明人： Jian-Hua Duan ,  Rui-Xia Fei ,  Shao-Hua Fang ,  Qing-Hua Su

IPC分类号： H02M3/335

CPC分类号： H02M3/33507

摘要： A power adapter with voltage-stabilized compensation includes a pulse frequency modulation circuit to generate a driving pulse which has a variable OFF time interval to control power transformed and output by a transformer. The power adapter also has an ancillary coil to induce a feedback signal on the secondary coil of the transformer. The pulse frequency modulation circuit includes a time interval modulation unit to receive the feedback signal and a feedback compensation unit. The time interval modulation unit sets a level voltage compared with the feedback signal to generate a sample signal to modulate the OFF time interval. The feedback compensation unit provides a compensation signal to the time interval modulation unit to change the size of the feedback signal or sample signal thereby to compensate the voltage output from the secondary side.

摘要翻译： 具有电压稳定补偿的电源适配器包括脉冲频率调制电路，用于产生具有可变的关闭时间间隔的驱动脉冲，以控制由变压器变换和输出的功率。 电源适配器还具有辅助线圈以在变压器的次级线圈上感应反馈信号。 脉冲频率调制电路包括接收反馈信号的时间间隔调制单元和反馈补偿单元。 时间间隔调制单元设置与反馈信号相比的电平电压以产生采样信号以调制关断时间间隔。 反馈补偿单元向时间间隔调制单元提供补偿信号，以改变反馈信号或采样信号的大小，从而补偿从次级侧输出的电压。

公开(公告)号：US20100110735A1

公开(公告)日：2010-05-06

申请号：US12265535

申请日：2008-11-05

申请人： Jian-Hua Duan ,  Rui-Xia Fei ,  Shao-Hua Fang ,  Qing-Hua Su

发明人： Jian-Hua Duan ,  Rui-Xia Fei ,  Shao-Hua Fang ,  Qing-Hua Su

IPC分类号： H02M3/337

CPC分类号： H02M3/33507

摘要： A power adapter with voltage-stabilized compensation includes a pulse frequency modulation circuit to generate a driving pulse which has a variable OFF time interval to control power transformed and output by a transformer. The power adapter also has an ancillary coil to induce a feedback signal on the secondary coil of the transformer. The pulse frequency modulation circuit includes a time interval modulation unit to receive the feedback signal and a feedback compensation unit. The time interval modulation unit sets a level voltage compared with the feedback signal to generate a sample signal to modulate the OFF time interval. The feedback compensation unit provides a compensation signal to the time interval modulation unit to change the size of the feedback signal or sample signal thereby to compensate the voltage output from the secondary side.

摘要翻译： 具有电压稳定补偿的电源适配器包括脉冲频率调制电路，用于产生具有可变的关闭时间间隔的驱动脉冲，以控制由变压器变换和输出的功率。 电源适配器还具有辅助线圈以在变压器的次级线圈上感应反馈信号。 脉冲频率调制电路包括接收反馈信号的时间间隔调制单元和反馈补偿单元。 时间间隔调制单元设置与反馈信号相比的电平电压以产生采样信号以调制关断时间间隔。 反馈补偿单元向时间间隔调制单元提供补偿信号，以改变反馈信号或采样信号的大小，从而补偿从次级侧输出的电压。

公开(公告)号：US20100103705A1

公开(公告)日：2010-04-29

申请号：US12260585

申请日：2008-10-29

申请人： Shao-Hua FANG ,  Chao Chen ,  Jian-Hua Duan ,  Ya-Jiang Zhu

发明人： Shao-Hua FANG ,  Chao Chen ,  Jian-Hua Duan ,  Ya-Jiang Zhu

IPC分类号： H02M3/335

CPC分类号： H02M3/33507 ,  H02M1/32

摘要： A short circuit protection circuit for a pulse width modulation (PWM) unit which includes a PWM logic control circuit, an under voltage lookout (UVLO) circuit and an internal clock circuit; wherein the UVLO circuit detecting a bias power (Vcc) and delivering an UVLO signal when the bias power is judged excessively low, the PWM unit further comprising: a short circuit detector, a short circuit recovery circuit and a frequency multiplexer. The short circuit detector is to detect the UVLO signal and generate a short signal. The short circuit recovery circuit to set a pre-determined recovery time and generate a recovery signal when the pre-determined recovery time ends. The frequency multiplexer which is triggered by the short signal when the short circuit event occurs to change a switching frequency to a short PWM frequency, and triggered by the recovery signal to restore the switching frequency.

摘要翻译： 一种用于脉宽调制（PWM）单元的短路保护电路，其包括PWM逻辑控制电路，欠压监视（UVLO）电路和内部时钟电路; 其中所述UVLO电路检测偏置功率（Vcc）并且当所述偏置功率被判断为过低时传送UVLO信号，所述PWM单元还包括：短路检测器，短路恢复电路和频率复用器。 短路检测器是检测UVLO信号并产生一个短信号。 短路恢复电路设置预定的恢复时间，并在预定的恢复时间结束时产生恢复信号。 当发生短路事件时由短信号触发的频率复用器将开关频率改变为短的PWM频率，并由恢复信号触发以恢复开关频率。