Here's a simple rule to help remember "Sinking / Sourcing".
VCC=Power Source
In a very simple form, relative to VCC, think of the transistor as either coming before or after the device.
If the transistor is connected between VCC and the device, it is sourcing current.
If the transistor is connected between the device and ground, it is sinking current.
VCC=Power Source
In a very simple form, relative to VCC, think of the transistor as either coming before or after the device.
If the transistor is connected between VCC and the device, it is sourcing current.
If the transistor is connected between the device and ground, it is sinking current.
