|
LP2996 Datasheet, PDF (15/18 Pages) National Semiconductor (TI) – DDR Termination Regulator | |||
|
◁ |
à
දతͳÎÏϦÎÊγϣϯճ࿠( ÍÍ®Í)
HSTL ÎÏϦÎÊγϣϯ
LP2996 ͸ɺVDDQ Í´ 1.5V ϨÊϧÎàªà¬Í¢ÎÍ©ÍͰɺØà¯Í´
HSTL ÎÏϦÎÊγϣϯʹద༻ͰÍÎ͢ɻλÊÏÏÊγϣϯà°ß
ʹ༩
ÍÎÎÎ VTT ͱ VREF ిѹ͸ÍÎͦ 0.75V ʹͳÎÎ͢ɻ à ·à°¦Í³à©
à³³Îà²ÎͨÎÍ´ AVINͱPVIN ͸ 2.5VϨÊϧʹàªà¬Í ͯÍÍ©ÍÍÉ»
FIGURE 12. HSTL Application
QDR ÎÏϦÎÊγϣϯ
ΫϫοÏ
ɾÏÊλɾϨÊÏ (QDR) ÎÏϦÎÊγϣϯ͸ߴÍÏÏϦà©à³³
Îà²ÎͨÎʹෳ਺ͷνÏÏϧÎà¢à¼»Í Î͢ɻͦͷͨÎÏε৴߸ઢ
਺Íà«¿ÍɺλÊÏÏÊγϣϯʹà¶à½Í³à°¿à½¶Ï¨ÏϧÎàÍÍͳÎÎ͢ɻ
ͦÍͰλÊÏÏÊγϣϯͰ͸ɺෳ਺νÏÏϧͷ֤νÏÏϧÍͱʹݸà¸
Í· LP2996 Îà¢à¼»Í¢ÎÍͱÎਪà¦Í Î͢ɻجàµÏ¨Î Î΢ÏÎà¯à¥Ô½
Í°Íɺ֤ϨΪϡϨÊλͷ಺෦ফà¶
à°¿à¾Îà½ÍÎÎÎ͢ɻ ֤ϨΪϡ
ϨÊλÍÎà¥à¾ÍÎÎݸÊÍ· VREF ৴߸ÎÖ¤ DIMM ÏϯΫʹ༩Í
Î͢ɻνοÏηοÏ༻ͷϦÏÎϨϯεిѹ͸ɺॴÛతʹà°ß
෼ѹÎ
ߦÍÍɺLP2996 Í·Íͪͷ 1 ÍÍÎ༩ÍÎ͢ɻ VREF ͸ VTT ʹ௥
à¥Í¢ÎÍͱÍÎà ÝÎɺÎͨÏÏΠεØͷ͹ÎÍÍ͸à¦ÍÍͨÎɺ
Ö¤ LP2996 ͷϦÏÎÏ¨Ï¯Îµà°¿Ñ¹Í·à ©Í¸ÎÍ£ÍͰ͢ɻ
à¥à¾Î¯Ï¯Ïϯαͷબà
LP2996Î SSTL-2 I/O ৴߸ͷλÊÏÏÊγϣϯ༻ʹà¢à¼»Í ͨÎÏϦ
ÎÊγϣϯͰ͸ɺFigure 13 Í´à£Í¢à
දతÎÏϦÎÊγϣϯճà¿Î
ద༻ÕೳͰ͢ɻ
FIGURE 13. Typical SSTL-2 Application Circuit
ÍÍ·Õ³à¿Í¸Éºà ·à¦Í·Ø¬àµà»à©µÍ±à ·à¦Í·à·¦à¶¼à°ºà¨ºÍ°Î»ÊÏÏÊγϣ
ϯճà¿Î࣮͢ÎÍÍ¯Í Ý±É» બàÍ¢ÎÍίϯÏϯαͷ༰à¾Í¸ÉºÎ»Ê
ÏÏÊγϣϯ͢Îà§´ß¸àª¢à¨ºÍ±à ·àà·ÕిྲྀʹÒà¬Í ͯÒͳÎÎÍ¢
ÍɺVTT Íà¯Íà´àª¢Í°à·¼à´ÍÎͯÍÎÏβÊÏÊÏ
ÎÎÏϦÎÊ
γϣϯͰ͸ɺෳ਺ͷÏϧΫɾίϯÏϯαÎà¢à¼»Í ɺÍÎʹߴप೾Ï
ΧοÏϦϯάɾίϯÏϯαÎ௥ÕÍ¢ÎÍͱÍ๬ÎÎÎ͢ɻà£Í· Figure
14 ʹɺ2 ݸͷÏϧΫà¥à¾Î¯Ï¯ÏϯαÎÉºà ·à°¦Í³Òà®Í°ÍÎ VTT
à«Í·à¾àºÍ´à´à®Í ͨճà¿à¾«Îà£Í Î͢ɻESR Íà¦ÍÍÍÍίεÏ
Í௿Íà༰à¾ÎϧÏిղίϯÏϯαÎà¢à¼»Í ͯÍÎ͢ɻ
15
www.national.com/jpn/
|
▷ |