发明名称 |
Light emitting diode driver having cascode structure |
摘要 |
A driver circuit for driving light emitting diodes (LEDs). The driver circuit includes: a string of LEDs divided into n groups, the n groups of LEDs being electrically connected to each other in series, a downstream end of group m−1 being electrically connected to the upstream end of group m, where m is a positive number equal to or less than n. The driver circuit also includes a power source coupled to an upstream end of group 1 and operative to provide an input voltage and a plurality of current regulating circuits, each of the current regulating circuits being coupled to the downstream end of a corresponding group at one end and coupled to a ground at the other end and including a sensor amplifier and a cascode having first and second transistors. |
申请公布号 |
US9144123(B2) |
申请公布日期 |
2015.09.22 |
申请号 |
US201113244873 |
申请日期 |
2011.09.26 |
申请人 |
|
发明人 |
Jeong Jae Hong |
分类号 |
H05B41/28;H05B33/08 |
主分类号 |
H05B41/28 |
代理机构 |
Patent Office of Dr. Chung Park |
代理人 |
Patent Office of Dr. Chung Park |
主权项 |
1. A method for driving light emitting diodes (LEDs), comprising:
providing a string of LEDs divided into groups, the groups being electrically connected to each other in series; providing a power source electrically connected to the string of LEDs; coupling each of the groups to a ground through a current regulating circuit, the current regulating circuit including a cascode structure having first and second transistors, a source of the first transistor being directly connected to a drain of the second transistor so that the source of the first transistor and the drain of the second transistor have a same voltage potential during operation; and increasing an input voltage from the power source to turn on the groups in a downstream sequence. |
地址 |
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