application note 1032 an introduction to fpd-link (jp) figure 5. seven bits of lvds in one clock...
TRANSCRIPT
DS90C3201,DS90C3202,DS90C363B,DS90C365A,DS90C383B,DS90C385A,DS90C387,DS90C387A,DS90C387R,DS90CF363B,DS90CF364,DS90CF364A,DS90CF366,DS90CF383B,DS90CF384,DS90CF384A,DS90CF384AQ,DS90CF386,DS90CF388,DS90CF388A,DS90CF564
Application Note 1032 An Introduction to FPD-Link
Literature Number: JAJA269
National SemiconductorApplication Note 1032Susan Poniatowski1998幎 7æ
1© National Semiconductor Corporation AN012599-05-JP
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-1032
FPD Link ã«ã€ããŠã®æŠè«
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FPD Link ãããã»ãã
FPD Link (Flat Panel Display Link)ãããã»ããã¯ãã°ã©ãã£ãã¯ã»ã³ã³ãããŒã©ããLCDããã«ãžã®ããŒã¿è»¢éã®ããã«ãç¹å¥ã«æ§æãããã€ã³ã¿ãã§ãŒã¹ã»ããã€ã¹ã»ãã¡ããªã§ããé«éãã€äœæ¶è²»é»åã§ã®ããŒã¿è»¢éãéæããããã«ãLVDS ( å°æ¯å¹ å·®åä¿¡å· )æè¡ãæ¡çšãããŠããŸããããã«ããSVGA (800Ã600)ããXGA (1024Ã768)ãªã©ã®ãããªãã€ãšã³ãã»ãã£ã¹ãã¬ã€ã®å°å ¥ãå¯èœãšãªããŸãã
ãããã®ãã€ãšã³ãã»ãã£ã¹ãã¬ã€ã®æ§èœã®éçãæ¯é ããŠããã®ã¯ãé床ãæ¶è²»é»åãEMIãªã©ã®åé¡ã§ãããŠãŒã¶ãŒã¯ãŸããå®éã®ã€ã³ã¿ãã§ãŒã¹ã«ãé¢å¿ããããŸããããã«ã¯ãããå°ãªãä¿¡å·ç·ãåªããŠããŸããFPD Linkãããã»ããã¯ããããåé¡ç¹ã«ãLVDSæè¡ãšTTLä¿¡å·ãããé«éãªLVDSä¿¡å·ã«å€æãããŠããã¹ããšãã£ã¹ãã¬ã€éã®ã€ã³ã¿ãã§ãŒã¹ã蚱容ããŸããæšæºçãªã¢ããªã±ãŒã·ã§ã³ (Figure 1åç § )ã§ã¯ãã°ã©ãã£ãã¯ã»ã³ã³ãããŒã©ããéãããTTLã¬ãã«ã® RGBãšã³ã³ãããŒã«ã»ããŒã¿ã¯ãFPDLinkãã©ã³ã¹ããã¿ã«å ¥åãããŸãããã©ã¬ã« TTLããŒã¿ã¯ãLVDS
ä¿¡å·ã«å€éåã»å€æãããŸããFPD Linkãã©ã³ã¹ããã¿ã®åºåã¯LVDSããŒã¿ãããã£ã¹ãã¬ã€ã®ãã¶ãŒããŒãã«æ¥ç¶ãããŠããã±ãŒãã«ãžéããŸãããã® LVDSããŒã¿ã¯ããã£ã¹ãã¬ã€ã® FPD Linkã¬ã·ãŒããžã±ãŒãã«ãéããŠéãããŸããåãåãããããŒã¿ã¯åé¢ã»å€æãã㊠TTLã¬ãã«ã®ä¿¡å·ã«æ»ãããã¿ã€ãã³ã°ã»ã³ã³ãããŒã©ã®å ¥åã«éãããŸãããã®å€éåããããã©ã¬ã« TTLä¿¡å·ã¯ãå¹ ã®çãã€ã³ã¿ãã§ãŒã¹ãééããããé«éãªããŒã¿ã蚱容ããé«ã垯åã®å¿ èŠãªéä¿¡ãå¯èœãšããŸãã
FPD Linkãããã»ããã¯ã18ããããš24ãããã®ã«ã©ãŒãã£ã¹ãã¬ã€ã®ããã«èšèšããããã©ã³ã¹ããã¿ (TTLãã LVDS ãžå€æ )ãšã¬ã·ãŒã (LVDSããTTLãžå€æ )ããæ§æãããŠããŸããããŸããŸãªã°ã©ãã£ãã¯ã»ã³ã³ãããŒã©ããã㯠LCDããã«ã»ã³ã³ãããŒã©ã®å€æ§ãªã€ã³ã¿ãã§ãŒã¹ãžã®å¯Ÿå¿ãå³ããããããŒã¿ã»ã¹ãããŒãä¿¡å·ã«é¢ããŠãç«ã¡äžãããšããžåãç«ã¡äžãããšããžåãéžæå¯èœåãæããŠããŸããFPD Link 補åãã¡ããªã«ã¯ã20MHz ãã65MHzã®åšæ³¢æ°ç¯å²ããµããŒããã5VãŸã㯠3.3Vãããã»ãããã©ã€ã³ã¢ãããããŠããŸããæ§æã¯Figure 2ãåç §ããŠãã ããã
FIGURE 1. Typical FPD Link Application (24-Bit Color)
FIGURE 2. FPD Link Chipset for 18-Bit Color
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LVDS- åè¶ãããã¯ãããžãŒåè¶ãããã¯ãããžãŒåè¶ãããã¯ãããžãŒåè¶ãããã¯ãããžãŒ
LVDS ã¯é«éã®ããŒã¿äŒéãã³ã¢ã³ã¢ãŒãã»ãã€ãºã®é€å»ãäœæ¶è²»é»åãèŠæ±ãããã¢ããªã±ãŒã·ã§ã³ããµããŒãããããã«éçºãããå·®åä¿¡å·åæè¡ã§ããå°ããªã¹ã€ã³ã°é»å§ (345mV)ãšå·®åä¿¡å·ã¯æ¬è³ªçã«ãã€ãºã®åœ±é¿ ( äŸãã°ãã¯ãã¹ããŒã¯ ) ãæžå°ãããé«ãåäœåšæ³¢æ°ã蚱容ããŸããå®é»æµåºåãã©ã€ãã¯ãäœæ¶è²»é»åã®ããã«èšèšãããŸããã1ã€ã® LVDSãã©ã€ãã®éæ¢æã® ICC㯠4mAãåäœæã® ICC㯠22mAã§ãããããã®ç¹è³ªã¯ãLVDSã®äœ EMIã«ãå¯äžããŠããŸãã
FPD Linkã䜿çšããèšèšã䜿çšããèšèšã䜿çšããèšèšã䜿çšããèšèš
FPD Linkãããã»ããã¯ãSVGA (800à 600)ã XGA (1024Ã768) ãªã©ã«äœ¿çšãããé«éã®ãã£ã¹ãã¬ã€ã»ã€ã³ã¿ãã§ãŒã¹ã®æ¯æŽã«å¿ èŠãªæ©èœãæäŸããŸãããããã®è£œåã䜿çšããèšèšæã«ã¯ãLVDSã®æ§èœãå®å šã«çºæ®ãããããã«æ³šæããªããã°ãªããŸããã
PCB ã®ã¬ã€ã¢ãŠãïŒã®ã¬ã€ã¢ãŠãïŒã®ã¬ã€ã¢ãŠãïŒã®ã¬ã€ã¢ãŠãïŒ LVDSã®ãã€ãºãš EMIã®äœæžã®å¹æãç²åŸããããã«ã¯ãå·®åä¿¡å·ã©ã€ã³ã®ã¬ã€ã¢ãŠãã«æ³šæããŠãã ããã察ã«ãªãå·®åä¿¡å·ã©ã€ã³ã¯ãä»ã®ä¿¡å·ããã®å¹²æžãé²ããå·®åä¿¡å·ã®ãã€ãºé€å»ã®å©ç¹ãå®å šã«åŒãåºãããã«ãåžžã«é£æ¥ããŠããªããã°ãªããŸãããPCBèšèšè ã¯ãŸãã察ã«ãªãä¿¡å·ç·ã®é·ããçããä¿ããªããã°ãªããŸãããé«éãªããŒã¿ã«ããèšèšãè¡ãéã«ã¯ãã€ã³ããŒãã³ã¹ã®äžé£ç¶ãå¶éãããŸã (ãã€ã¢ã¹ã®æ°ãæžãããçŽè§ã«æ²ããã¹ã«ãŒããŒã«ããªãããŸã )ã1ã€ã®ä¿¡å·ç·ã§èµ·ããã©ããªã€ã³ããŒãã³ã¹ã®äžé£ç¶ã§ããå·®åãã¢ãšãªãããäžæ¹ã®ä¿¡å·ç·ã«åæ ãããŸãããããã«å¯Ÿããæ€èšã¯ãé«ãåšæ³¢æ°ã§ã®æ§èœãšEMIã«äžå©ãªåœ±é¿ãäžããåå°ãã¯ãã¹ããŒã¯ãå¶éããŸãã
24ããããã18ããããžã®ã€ã³ã¿ãã§ãŒã¹ : 24ãããã»ãã©ã³ã¹ããã¿ãš18ãããã»ã¬ã·ãŒã (ãŸãã¯ãã®é )ãã€ã³ã¿ãã§ãŒã¹ããå Žåã¯å·¥å€«ãå¿ èŠã§ããéåžžãæäžäœã®ã«ã©ãŒã»ããã㯠24ãããã»ãã©ã³ã¹ããã¿ã® 4çªç®ã® LVDSãã£ãã«ã«å²ãåœãŠãããŸãããã®å Žåãäžäœã® 3ã€ã® LVDSããŒã¿ã»ãã£ãã«ã 18ãããã»ã¬ã·ãŒãã«æ¥ç¶ããŸããæ®ã£ã 4 çªç®ã® LVDSããŒã¿ã»ãã£ãã«ã¯éæŸã®ãŸãŸãšããŸãã
çµç«¯ïŒçµç«¯ïŒçµç«¯ïŒçµç«¯ïŒé»æµåºåã®ãã©ã€ãã䜿çšããããã«ã¯ãã¬ã·ãŒãã®å ¥åéã«çµç«¯æµæãå¿ èŠãšãªããŸããFPD Linkãããã»ããã¯ã1æ¬ã® 100Ωã®æµæãããããã®ã¬ã·ãŒãã®æ£è² ã®å ¥å端åã®éã«äœ¿çšããŸã (Figure 3åç § )ããã®ä»ã®ããã€ãã®å·®åäŒéæ¹åŒ(PECLïŒæ¬äŒŒ ECL)ã®ããã«ãè¿œå ã®ãã«ã¢ãããŸãã¯ãã«ããŠã³æµæã¯å¿ èŠãããŸãããè¡šé¢å®è£ çšã®æµæãããªãŒãç·ç«¯åãæã€æµæã«ããã€ã³ãã¯ã¿ã³ã¹ã®å¢å ãé²ãããã«æšå¥šãããŸãããããã®æµæã¯ãã¹ã¿ãã圢æãããã®ãé²ããå·®åäŒéçµè·¯ãå¹æçã«çµç«¯ããããã«ãã¬ã·ãŒãã®å ¥åã«ã§ããéãè¿ãã«å®è£ ãããã¹ãã§ãã
FIGURE 3. FPD Link Termination
ãã«ãããªã³ã°ã»ã³ã³ãã³ãµïŒãã€ãã¹ã»ã³ã³ãã³ãµã¯ãæ§èœãå¶éããã¹ã€ããã³ã°ã»ãã€ãºã®åœ±é¿ãäœæžããããã«å¿ èŠãšãªããŸãããã«ãããªã³ã°ã»ã³ã³ãã³ãµ (è¡šé¢å®è£ )ã¯ãããããã® VCCãšã°ã©ãŠã³ã端åã®éã«ããããå®è£ ãããããšãæšå¥šãããŸããæ¥ç¶ãšã³ã³ãã³ãµã®å®¹éã®äŸã«ã€ããŠã¯ãFigure 4 ãåç §ããŠãã ããã
FIGURE 4. Decoupling Configuration
ã±ãŒãã«ïŒã±ãŒãã«ïŒã±ãŒãã«ïŒã±ãŒãã«ïŒã±ãŒãã«ã¯ããã©ã³ã¹ããã¿ãšã¬ã·ãŒãéãæ¥ç¶ããããããçµã«ãªãå·®åLVDSä¿¡å·ãåãæ±ãå¿ èŠããããŸã (ä¿¡å·ç·ïŒ2æ¬ / çµ )ããã£ãã«ããã8ãããã®ãããã»ãã (24ãããå )ã«å¿ èŠãªä¿¡å·ç·æ°ã¯ 10æ¬ (5ã㢠)ã§ãããã£ãã«ããã6ãããã®ãããã»ãã (ãããå )ã«å¿ èŠãªä¿¡å·ç·æ°ã¯ 8 æ¬ (4 ã㢠)ã§ãããã㯠28æ¬ãªãã 21æ¬ã®ä¿¡å·ç·ãå¿ èŠãšãªã TTLã€ã³ã¿ãã§ãŒã¹ã«å¯ŸããŠãå€§å¹ ãªã±ãŒãã«æ°ã®åæžãšãªããŸããã·ãŒã«ããããã±ãŒãã«ã¯ãEMIã®äœæžã«é¢ä¿ããããã€ãºã®æŸå°ãæžå°ãããŸããããã«ãããããã®å·®åãã¢ã»ã±ãŒãã«éã®ã°ã©ãŠã³ãã»ã©ã€ã³ã¯ããããã£ãããã€ãºã«å¯ŸããŠã·ãŒã«ããšããŠåããŸãããã®ã°ã©ãŠã³ããžã®æ¥ç¶ã¯é£æ¥ãããã¢ã»ã±ãŒãã«éã®ãã€ãºã®çµåãé²ãéå£ãšãªããããã«ããä»å çãªé»çã®åœ±é¿ãæžå°ããŸãããŸãããã€ãºãã·ãŒã«ãããã©ã³ã¹ããã¿ãšã¬ã·ãŒãéã®äœã€ã³ããŒãã³ã¹ã§ã®ã°ã©ãŠã³ãæ¥ç¶ã¯ãã³ã¢ã³ã¢ãŒãã®ãªã¿ãŒã³ãã¹ãäœããŸããæäœã§ã 2 ç®æã®ã°ã©ãŠã³ããžã®æ¥ç¶ãããã®äœã€ã³ããŒãã³ã¹ã§ã®ãã¹ã®ããã«æšå¥šãããŸãã
çæ³çãªã±ãŒãã« /ã³ãã¯ã¿ã»ã€ã³ã¿ãã§ãŒã¹ã¯ã100Ωäžå®ã®å·®åã€ã³ããŒãã³ã¹ãæã¡ãŸããã±ãŒãã«ã»ã¹ãã¥ãŒã¯ãååãªããŒã¿ã»ãµã³ããªã³ã°ã»ãŠã€ã³ããŠãç¶æããããã« 250ps (65MHz)以äžã«ããããšãæšå¥šãããŸãããšããžã»ã¬ãŒãã®æžè¡°ã¯ãé«ãåšæ³¢æ°ã«ãããä¿¡å·ã®äœäžãé²ãããã«å¶éãããªããã°ãªããŸãããã¹ãã¥ãŒãšãšããžã»ã¬ãŒãã®æžè¡°ã®åæ¹ã¯ãã±ãŒãã«ã®é·ãã®é¢æ°ã«ãªããŸãããã¹ããšãã£ã¹ãã¬ã€ã®éã®è·é¢ãå¢å ããå Žåãé«å質ãªã±ãŒãã«ãä¿¡å·ã®å®å šæ§ãä¿è·ããããã«å¿ èŠã§ãã
ãã¹ããšLCDãã£ã¹ãã¬ã€ã®å éšæ¥ç¶ã¯éåžžçãã«ãããããããFPD Linkãã©ã³ã¹ããã¿ã¯ã5m ãè¶ ããé·ãã®ã±ãŒãã«ããã©ã€ãã§ããŸããããã«ãããFPD Linkã¯ãªã¢ãŒãã»ãã£ã¹ãã¬ã€ã®ã¢ããªã±ãŒã·ã§ã³ã«äœ¿çšå¯èœãšãªããŸãã
TTL ä¿¡å·ããä¿¡å·ããä¿¡å·ããä¿¡å·ããLVDS ä¿¡å·ãžã®å€æä¿¡å·ãžã®å€æä¿¡å·ãžã®å€æä¿¡å·ãžã®å€æ
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FIGURE 5. Seven Bits of LVDS in One Clock Cycle
FIGURE 6. 28 Parallel TTL Data Inputs Mapped to LVDS Outputs (DS90CR581)
FIGURE 7. 21 Parallel TTL Data Inputs Mapped to LVDS Outputs (DS90CR561)
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