DigiTan
New Member
What exactly does sinking mean when you're talking about a logic device's output? Is "sourcing/sinking" similar to "fan-in/fan-out" in any way?
Here's what I mean...(from an AVR datasheet)...
Here's what I mean...(from an AVR datasheet)...
Port B is an 8-bit bi-directional I/O port. Port pins can provide internal pull-up resistors
(selected for each bit). PB0 and PB1 also serve as the positive input (AIN0) and the
negative input (AIN1), respectively, of the On-chip Analog Comparator. The Port B output
buffers can sink 20 mA and can drive LED displays directly. When pins PB0 to PB7
are used as inputs and are externally pulled low, they will source current if the internal
pull-up resistors are activated. The Port B pins are tri-stated when a reset condition
becomes active, even if the clock is not active.