标题: PDS [打印本页] 作者: Iric071 时间: 2007-12-28 17:23 标题: PDS PCB Stackup and Layer Order中: % ?7 n2 _/ B7 z$ I) sPower supplies with high transient current should have their associated VCC planes close to the 8 t& s; L" Q, x' U/ |- h" qtop surface (FPGA side) of the PCB stackup to decrease the distance in the vertical direction' w/ y% ]9 G: J. J" N7 u
that currents travel through VCC and GND vias before reaching the associated VCC and GND/ p6 X6 g" l5 U" c
planes. As mentioned in the previous section, every VCC plane should have a GND plane% V' X5 L/ S k/ H7 o2 C! q
adjacent to it in the stackup to reduce spreading inductance. Since high-frequency currents u3 r; F4 ]& L& s" s6 i
couple tightly due to skin effect, the GND plane adjacent to a given VCC plane tends to carry the ) P8 g: k+ O5 ]" amajority of the current complementary to that in the VCC plane. For this reason, adjacent VCC+ C8 l; z/ F, J5 u Q
and GND planes are considered as a pair. 3 i9 _4 K. f5 P, D& e1 @" G這裡面,說的VCC,GND層到底所何放置?( T' `9 k( A) }$ H+ l; L0 L
謝謝!作者: alooha 时间: 2007-12-29 09:55
提示: 作者被禁止或删除 内容自动屏蔽作者: liujie123 时间: 2007-12-29 11:28
提示: 作者被禁止或删除 内容自动屏蔽
