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: 8 j' r6 F6 t, B. ?$ E7 [$ LPower supplies with high transient current should have their associated VCC planes close to the( X: c' E* h1 Z9 ]$ v
top surface (FPGA side) of the PCB stackup to decrease the distance in the vertical direction0 p" P. d$ U- [! m5 T7 M
that currents travel through VCC and GND vias before reaching the associated VCC and GND ; S# k _! M4 w8 T S+ Pplanes. As mentioned in the previous section, every VCC plane should have a GND plane ( ^( N X8 F2 L, C: t S5 r9 Fadjacent to it in the stackup to reduce spreading inductance. Since high-frequency currents 7 c3 X, n0 r9 n" L" O2 scouple tightly due to skin effect, the GND plane adjacent to a given VCC plane tends to carry the5 \! F; Z, R" J3 X& P' b. B4 p; I/ j
majority of the current complementary to that in the VCC plane. For this reason, adjacent VCC 4 _% ^6 [ j3 K: S6 W* J- D9 zand GND planes are considered as a pair.* D6 |2 n2 \; J' j1 v- u, q1 f
這裡面,說的VCC,GND層到底所何放置? # s6 q1 [" q# g* a1 q* Z1 `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
