SHANGHAI BRIGHT POWER SEMICONDUCTOR CO., LTD. Patent applications |
Patent application number | Title | Published |
20140354186 | CURRENT RIPPLE CANCELING LED DRIVER - A current ripple canceling light-emitting diode (LED) driver is disclosed. The input current source contains a current ripple. The LED load is connected to the drain of a power switch. The source of the power switch is connected to a current sensing resistor. The gate of the power switch is connected to the output of an operational amplifier. The operational amplifier compares the voltage signal across the current sensing resistor with a dynamic reference voltage. The dynamic reference voltage is adjusted according to the gate or drain voltage of the power switch. The LED load current is controlled to be a nearly no ripple DC current. | 12-04-2014 |
20140111093 | AVERAGE LINEAR LED DRIVER CIRCUIT - An average linear light-emitting diode (LED) driver circuit is disclosed. An inputting alternating-current (AC) voltage is connected to a rectifier bridge. An LED load is paralleled with a filtering capacitor and connected to a power switch. A compensation network and a voltage feedback network are included. When the output voltage of the rectifier bridge is higher than the voltage of the filtering capacitor, the drain voltage of the power switch is increased. The voltage feedback network decreases or turns off the current in the power switch. The compensation network controls the average current in the power switch to be equal to the desired LED load current. The average linear LED driver circuit intelligently controls the driver current, reduces the system power loss and increases the system efficiency. The LED driver maintains high conversion efficiency, especially under wide input voltage conditions. | 04-24-2014 |