DocumentCode :
2734438
Title :
Chip Level Techniques for EMI Reduction in LCD Panels
Author :
Kim, Min-woo ; Kim, Do-Wan ; Koo, Bon-sung ; Kim, Yong-bum ; Choi, On-sik ; Kim, Nam-deog
Author_Institution :
Samsung Electron. Co., Ltd., Asan
fYear :
2009
fDate :
12-16 Jan. 2009
Firstpage :
441
Lastpage :
444
Abstract :
This paper presents chip level techniques to improve electro-magnetic interference (EMI) characteristics of LCD-TV panels. A timing controller (TCON) uses over-driving algorithms to improve the response time of liquid crystals (LC). Since this algorithm needs previous frame data, external memory such as double data rate synchronous DRAM (DDR SDRAM) is widely used as a frame buffer. A TTL interface between the TCON and memory is used for read and write operations, generating EMI noise. For reduction of this EMI, three methods are described. The first approach is to reduce the driving current of data I/O buffers. The second is to adopt spread spectrum clock generation (SSCG), and the third is to apply a proposed algorithm which minimizes data transitions. EMI measurement of a 32" LCD-TV panel shows that these approaches are very effective for reduction of EMI, achieving 20 dB reduction at 175 MHz.
Keywords :
DRAM chips; electromagnetic interference; liquid crystal displays; EMI measurement; EMI reduction; LCD-TV panels; chip level techniques; data I-O buffers; double data rate synchronous DRAM; electro-magnetic interference; frequency 175 MHz; liquid crystals; over-driving algorithms; read operations; spread spectrum clock generation; timing controller; write operations; Circuit noise; Clocks; Delay; Driver circuits; Electromagnetic interference; Frequency; Liquid crystals; Noise generators; Signal generators; Timing;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Electromagnetic Compatibility, 2009 20th International Zurich Symposium on
Conference_Location :
Zurich
Print_ISBN :
978-3-9523286-4-4
Type :
conf
DOI :
10.1109/EMCZUR.2009.4783485
Filename :
4783485
Link To Document :
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