原创 什么是灌入电流与吸收电流

Sinking and sourcing current
Chip outputs are often said to 'sink' or 'source' current. The terms refer to the direction of the current at the chip's output.
If the chip is sinking current it is flowing into the output. This means that a device connected between the positive supply (+Vs) and the chip output will be switched on when the output is low (0V).

If the chip is sourcing current it is flowing out of the output. This means that a device connected between the chip output and the negative supply (0V) will be switched on when the output is high (+Vs).

对于输入电流的器件而言：
灌入电流和吸收电流都是输入的，
灌入电流是被动的，
吸收电流是主动的。

如果外部电流通过芯片引脚向芯片内‘流入’称为灌电流；
反之如果内部电流通过芯片引脚从芯片内‘流出’称为拉电流。

下面这个图有助于对sinking  current 和 sourcing current 的理解。