DSP-Based LED Current Balancing Driver with Low Error in Current Sharing
| Autor: | Ming-Jie Hong, 洪明傑 |
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| Rok vydání: | 2011 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 99 In this thesis, a LED current balancing driver is presented, which combines one Zeta converter and one current balancing circuit. Hence, the frond-end stage is the Zeta converter, which provides a step-down voltage conversion in this application, whereas the following stage is the current balancing circuit mainly constructed by several differential transformers. Above all, the Zeta converter provides not only energy for the LED string but also the path for the differential transformer during the demagnetization period, so as to improve the performance of current balancing. By doing so, unlike the traditional current balancing circuit dissipating the demagnetizing energy in the zener diode or the resistor, the demagnetizing energy is sent back to the energy-transferring capacitor of the Zeta converter. In the design of the LED module, the optimal number of LEDs per LED string and the optimal number of LED strings will be carried out, so as to reduce the complexity and cost of the proposed LED driver. For the digital control to be considered, the digital signal processor (DSP) named STM32F103VBT6 (ARM 32-bit Cortex™-M3 CPU) is used as a controller kernel, which possesses low power dissipation, low cost, high performance, etc. Finally, some simulation results are given to verify the feasibility of the proposed topology, and some experimental results are offered to demonstrate its effectiveness. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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