Invention Grant
- Patent Title: Drive circuit for parallel array of light emitting diodes
- Patent Title (中): 用于并联发光二极管阵列的驱动电路
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Application No.: US12777079Application Date: 2010-05-10
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Publication No.: US08552660B2Publication Date: 2013-10-08
- Inventor: Zutao Liu , Kun Cheng , Jianbo Sun , Gang Shi
- Applicant: Zutao Liu , Kun Cheng , Jianbo Sun , Gang Shi
- Main IPC: H05B37/02
- IPC: H05B37/02

Abstract:
The present invention relates to a parallel light emitting diode (“LED”) drive circuit and provides a drive circuit configured to drive a parallel array of LEDs. The drive circuit comprises: a plurality of switches, a plurality of sampling resistors, and a plurality of chopper amplifiers. Each switch is coupled to a respective LED in the LED array. Each chopper operational amplifier configured to receive a reference voltage and a switching control signal and generate an input offset voltage. Each chopper operational amplifier includes a differential amplifier including an input transistor pair and a current mirror transistor pair, of which the electrical positions can be reserved when the switching control signal is switched between a first state and a second state, wherein the offset voltage, which causes the lightness mismatching in a parallel LED circuit, can be cancelled.
Public/Granted literature
- US20110215727A1 Drive Circuit For Parallel Array of Light Emitting Diodes Public/Granted day:2011-09-08
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