A self-directing bus amplifier and method is disclosed, which includes an
input biased at a given voltage level and a tri-state amplifier with a
first input terminal coupled to the biased input and an output coupled to
an output bus. A field effect transistor with a gate terminal coupled to
the biased input and a source terminal coupled to ground potential with a
drain terminal coupled to an inhibiting input of the tri-state amplifier.
The drain terminal of the field effect transistor is biased, such that
when a signal is present on the input the field effect transistor turns
OFF, which enables the tri-state amplifier so that the signal is passed
through to the output bus.