DDR VREF

liushaowanwan

请问DDR的VREF电源信号走线有什么要求和他匹配的电阻该放在什么位置最好？

liushaowanwan

[/img] 如图，线宽只有8MIL，会出现什么情况啊？

szkalwa

VREF线宽须得大于20MIL

457958672

liushaowanwan 发表于 2014-5-5 11:51
[/img] 如图，线宽只有8MIL，会出现什么情况啊？

4 N1 d# L" Y; G3 Q( s& x' ]6 v就是一个参考电压  走8mil应该不会有什么问题

xfire

457958672 发表于 2014-5-6 12:40
0 @+ J8 i8 ]' S( y就是一个参考电压  走8mil应该不会有什么问题

VREF is not a high current supply, but it is important to keep it as quiet as possible with minimal inductance. The minimum nominal trace width for VREF is 20 mils. Necking down VREF to accommodate BGA escape and localized via congestion is acceptable, but care should be taken to keep VREF 20 mils wide as much as possible. VREF is a DC net and as such, trace delay is not critical, however, overall trace length should be kept to a minimum.