Design Of Analog And Digital Dimming Led Drive Circuit

With a global consensus on the development of low-carbon economy achieved,LED lighting, with its low power consumption, high brightness, long life, small size, good seismic performance, green, multi-color light, versatile advantages, market prospects continue warming. In recent years, LED landscape lighting products, lighting industry to flourish, from indoor and outdoor decorative lighting the lamp to the civilian field, to municipal lighting project, have been witnessed extensive use of LED lights, LED lights will become the world’s unmatched future of the mainstream source. As a key component,LED lighting driving circuit in the lamp is like the human heart just as important, drive power quality directly determines the reliability of the LED products and market development.This thesis analyzes and studies the piecewise linear LED driver circuit, and the architecture of the circuit, dimming, driving circuit module. Designed a digital and an analog dimming LED driver circuit.In the design process, the traditional LED drive improvements simplify the circuit, reducing the use of components, avoid the use of electrolytic capacitors, resulting in waste costs, greater efficiency over the entire brightness range.In the design process, improve the traditional LED driver circuit to simplify and reduce the use of components. Avoid using electrolytic capacitors, resulting in waste costs, greater efficiency in the full brightness range.Support analog dimming digital dimming, respectively, or in the case of complex dimming mode can make some simple synchronous operation.At high brightness or adjust the brightness of the occasion requires precise, digital dimming mode, because the pulse waveform can be controlled to a very high precision, so it is easy to achieve precision parts per million.In the precision is not very high noise levels or strictly controlled, analog dimming, convenient,high power factor, high efficiency, high reliability. At last, the whole circuit simulation, also verify that the individual chip protection and dimming function. In this paper, the work done in the following aspects:1 、 Analysis of the basic principles of the LED drive circuit and drive method,analysis piecewise linear constant current LED driver chip fundamentals.2、Different dimming mode analysis and comparison analog dimming, PWM dimming, SCR(TRIAC) dimming their advantages and disadvantages. Proposed and designed a kind of analog and digital dimming LED driver circuit.3、The peripheral circuit design of the overall system, Including the calculation and analysis of the basic parameters, use Altium Designer for PCB layout. Finally, based on BCD 0.8um process in Cadence Spectre simulation environment was validated simulation results verify the correctness of the circuit design.4、Build the actual circuit, testing and analysis circuit,after completing the actual circuit design and construction,Circuit testing,Solve the dimming stroboscopic problems may arise in the process.