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：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。