公开(公告)号：US10034335B1

公开(公告)日：2018-07-24

申请号：US15627239

申请日：2017-06-19

申请人： Taiwan Semiconductor Co., Ltd.

发明人： Wei-Chun Hsiao ,  Yueh-Hua Chiang

IPC分类号： H05B33/08

摘要： A switching mode constant current led driver including an energy transmission unit, an LED module, a power transistor, a resistor and a control unit, the control unit including a driving unit for generating a driving voltage signal, and a duty cycle determining unit for determining a duty cycle of the driving voltage signal, wherein, the duty cycle determining unit determines a charging time for a reference current to charge an external capacitor according to a present time length, and determines a discharging time for a discharging current to discharge the external capacitor according to an inductor discharging time, the discharging current being proportional to an average value of an inductor charging status signal, and a comparing voltage is thereby generated on the external capacitor; and compares the comparing voltage with a saw-tooth voltage to generate a next time length of the duty cycle.

公开(公告)号：US09433045B2

公开(公告)日：2016-08-30

申请号：US14598453

申请日：2015-01-16

申请人： TAIWAN SEMICONDUCTOR CO., LTD.

发明人： Yueh-Hua Chiang

IPC分类号： H05B33/08 ,  H03K17/687

CPC分类号： H05B33/0815 ,  H03K17/687 ,  H05B33/0818 ,  H05B33/0845

摘要： A drive circuit with an external mode-adjusting pin includes an operational mode control circuit and a drive processing circuit. The operational mode control circuit further includes a current mirror circuit, a resistor, a capacitor and a comparator. The first comparator input port receives a reference voltage. The second comparator input port couples the second output port of the current mirror and the capacitor. The current mirror circuit bases on a resistor current to generate a charge current for charging the capacitor. As the charge voltage at the second comparator input port reaches a reference voltage, a trigger signal is outputted to the drive processing circuit for controlling the switches thereof. The external pin is defined to one end of the resistor or the capacitor for varying the resistance or the capacitance respectively to determine the operational mode for the driven circuit.

摘要翻译： 具有外部模式调节引脚的驱动电路包括操作模式控制电路和驱动处理电路。 操作模式控制电路还包括电流镜电路，电阻器，电容器和比较器。 第一比较器输入端口接收参考电压。 第二比较器输入端口连接电流镜的第二输出端口和电容器。 电流镜电路基于电阻电流以产生用于对电容器充电的充电电流。 当第二比较器输入端口的充电电压达到参考电压时，触发信号被输出到用于控制其开关的驱动处理电路。 外部引脚被定义为电阻器或电容器的一端，用于分别改变电阻或电容，以确定驱动电路的工作模式。