【请教】焊盘电气类型：Load、Source和Terminator 作用？

sxp雨落2

编辑原因：辅助修改标题。原标题：protel99

设定焊盘在网络中的电气类型,包括Load(负载焊盘)、Source(源焊盘)和Terminator(终结焊盘),这三张电气类型有什么区别？

wanghanq

从字面上理解是自动布局规则中会起作用。
（因接触电路相对简单，几乎没有用过自动布局。但在复杂的设计中，不结合自动布线是不可想象的事情）

如果把上面的按 意译 来翻译 是否 比较好理解？

Source(起点)、Load(中间点)、Terminator(终点)

ziyu_00

在AD的帮助文件中是这样描述这个参数的，大概意思是指这个选项主要用于连线的拓扑结构上。

Electrical Type - This field shows the current electrical status of the pad. This status is only relevant for component pads, and sets the transmission line characteristics for these pads. Pads can be designated as a Load, Source or Terminator. The Source and Terminator settings are used when a net requires one of the Daisy chain routing topologies. Click the field to change the electrical type from the drop down list.
http://techdocs.altium.com/display/ADRR/PCB_Dlg-Pad((Pad))_AD

在Daisy chain拓扑结构上也有描述：
http://techdocs.altium.com/display/ADRR/PCB_Pnl-PCB((PCB))_AD

Daisy Simple - this topology chains all the nodes together, one after the other. The order they are chained is calculated to give the shortest overall length. If a source and terminator pad are specified, then all other pads are chained between them to give the shortest possible length. If multiple sources (or terminators) are specified, they are chained together at each end


Daisy Balanced - this topology divides all the loads into equal chains, the total number of chains equal to the number of terminators. These chains then connect to the source in a star pattern. Multiple source nodes are chained together


Daisy Mid-Driven - this topology places the source node(s) in the center of the daisy chain, divides the loads equally and chains them off either side of the source(s). Two terminators are required, one for each end. Multiple source nodes are chained together in the center. If there are not exactly two terminators the Daisy-Simple topology is used.

sxp雨落2

为什么一般把焊盘都设为load型的？

ziyu_00

sxp雨落2 发表于 2014-9-9 10:00
为什么一般把焊盘都设为load型的？

可以把load型认为是既可以作为输入也可以作为输出