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Design Of LED Constant-current Driver Circuit With 8 Channel

Posted on:2016-08-18Degree:MasterType:Thesis
Country:ChinaCandidate:B ZhuFull Text:PDF
GTID:2308330473465322Subject:Integrated circuit engineering
Abstract/Summary:PDF Full Text Request
As for the energy crisis, greenhouse effect and the ecological environment is deteriorating, modern people are eager to change the way to acquire energy and improve the energy utilization. In this situation, LED(Light Emitting Diode) come into people’ sight for its advantages, such as high brightness, high efficiency, long life, low energy consumption, small pollution and chromatographic performance, it will become a new generation of green energy. At the same time, LED is widely used in many aspects, which greatly promote the research and development of LED driver chip. However, the main structure of LED is a PN junction, its I-V characteristic curve is a non-linear relationship,according to it,the tiny change of the positive voltage will cause great change of LED current, when the current has changed, may lead to serious change of the white LED color. In order to avoid color offset and ensure the constant brightness, LED should be driven by constant current。First of all,the paper introduces some characteristics of LED, the luminous mechanism, the connection mode; then a detailed analysis of the circuit principle and the respective characteristics of various common LED drive, analyzed and compared the constant current IC system schemes which are often used, according to the system design requirements, puts forward the design framework of the whole circuit, with the overall circuit the function completed the design of four key modules, including the reference voltage circuit, the constant current circuit, the output driver circuit and temperature protection circuit.Based on analyzing the working principle of the sub circuit, has carried on the simulation verification and performance parameters of the sub circuit using the Spectre simulation software. Then the simulation and layout design of the whole circuit. This time we use the CSMC 0.8um process, the input voltage range of 3.5V to 6V, the output current of each path can be adjusted according to the actual demand, the output current does not increase with the voltage of power supply, it has a good constant current performance when in the temperature range of-40-125; voltage output end can bear 10 V, to meet the demands of multiple LED series. Compared with the constant current LED driver traditional multi-channel, the structure has a good multi-channel driving capability, high current mathing precision.
Keywords/Search Tags:LED drive, constant current drive, linear constant current, current adjustable
PDF Full Text Request
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