|
LP2996 Datasheet, PDF (16/18 Pages) National Semiconductor (TI) – DDR Termination Regulator | |||
|
◁ |
à
දతͳÎÏϦÎÊγϣϯճ࿠( ÍÍ®Í)
FIGURE 14. Typical SSTL-2 Application Circuit for Motherboards
Ұൠͷ PC ÎÏϦÎÊγϣϯͰ͸ɺÏδϡÊϧʹ࣮૷ÍÎͨ DDR-
SDRAM DIMM Í´Îͬͯà¯ÍΠϯλÊίÏΫÏÍà©Í¡ÎͨÎɺà¬à¨º
Í·ÏΧοÏϦϯάÍà¶à½Í°Í¢É»Í¦Í·Í¨Îɺ௨ৠ1000ÐF ͷ༰à¾àµ£
ÒÍ·ÎϧÏిղίϯÏϯαÎÏϧΫɾίϯÏÏ¯Î±Í±Í Í¯à¢à¼»Í Î͢ɻ
PCB àªÍ¢ØÍ´ÜÎßà¾
1. ÏÏ«ÊɾϨÊϧͷà³à¾Î¯Ï¯Ïϯα͸ɺÕೳͳݶΠPVIN àºà¢ Í·
ÛÍÍ´à´à®Í ͯÍÍ©ÍÍÉ»
2. VSENSE àºà¢ ʹ͸ɺVTT λÊÏÏÊγϣϯÍÎÎÏεͷϨΪϡϨÊ
γϣϯÍà¶à½Í³à°ºÍ´àªà¬Í ͯÍÍ©ÍÍÉ»ÏβÊÏÊÏ
ɾÎÏϦÎÊ
γϣϯͰ͸λÊÏÏÊγϣϯɾÏεͷத఺Íཧà«à°¤Í°Í¢É»
3. VDDQ à³à¾Í¸ÉºDIMM Îͨ͸νοÏηοÏÍ· VDDQ ʹݯిରÍ
ͯϦÏÊÏɾηϯεͱͳÎÎÍÍ´àªà¬Í Î͢ɻ ಺෦ϦÏÎϨϯεి
ѹÎà ·Îà©à±ß´Íà©à©Í°ÍÎÎÍʹͳÎÎ͢ɻ
4. ೤à²à©Îվળ͢Îʹ͸ɺÏοÎÊδÍÎÍ·à¹à³¤à¾Îà«¿Îͨ͢Î
ʹදà»à«Í·à²à´©ÎàÍÍÍ Í¯ÍÍ©ÍÍɻάϥ΢ϯÏ
à´àª¢Í±à²ºà·¦Î¬
ϥ΢ϯÏ
ɾÏϨÊϯÎàªà¬Í¢Îà¬à¨ºÍ·ÏÎÎà¹à³¤ÎॿÍÎ͢ɻÍ
Îʹɺ੡à¬Ø¬à¥ªÍ±Í ͯÚ༰ÍÎÎÍ·Í°ÍÎ͹ɺÏÎ͸ÏοÎÊ
δԼ෦ʹÎà´à®Í ͯÍÍ©ÍÍÉ»
5. VSENSE ৴߸ͷà´àª¢àªÍ°Ü͸ɺεΠονϯά͢ΠI/O ৴߸ÍÎ
ÏΠζÎरÎͳÍÎÍʹ஫ÒÍà¶à½Í°Í¢É» VSENSE àºà¢ Í·ÛÍ
Í´ 0.1ÐF ηϥÏοΫɾίϯÏϯαÎà®Íͱɺ޷ÎÍ ÍͳÍߴप೾৴
߸ÎÏÎϧλϦϯάͰÍÎ͢ɻ VSENSE à´àª¢Íà¯Íà§ß¹ÉºÍ±ÍÍ´
Ýà±¼Îà½Í Î͢ɻ
6. VREFʹ͸ϨΪϡϨÊγϣϯà©à³³Í·Õ¾àª³Í·Í¨Îɺ0.1ÐF Ê 0.01ÐF
ͷηϥÏοΫɾίϯÏϯαÎàªà¬Í ͯÏΠζÎÏÎ ÏÎµÍ Í¯ÍÍ©Í
ÍɻίϯÏϯα͸ VREF àºà¢ Í·ÕೳͳݶÎÛÍÍ´à´à®Í ͯÍÍ©
ÍÍÉ»
www.national.com/jpn/
16
|
▷ |