Apparatus effecting interface between differing signal levels

摘要

An apparatus includes: a signal receiving unit receiving an input signal and presenting a first signal varying within a first signal range; a signal treating unit coupled with the signal receiving unit, receiving the first signal and presenting a second signal varying within a second signal range; and an output unit coupled with the signal treating unit. The signal treating unit and the output unit receive a control signal. The signal treating unit responds to the control signal to provide the second signal to the output unit when the control signal has a first value and to not provide the second signal to the output unit when the control signal has a second value. The output unit permits presentation of an output signal when the control signal has the first value and establishes the output signal at a predetermined value when the control signal has the second value.