资 源 简 介
The CY74FCT257T has four idenTIcal two-input mulTIplexers that select four bits of data from two sources under the control of a common data-select (S) input. The I0 inputs are selected when S is low, and the I1 inputs are selected when S is high. Data at the output is noninverted.
The CY74FCT257T is a logic implementaTIon of a four-pole, two-posiTIon switch, where the position of the switch is determined by the logic levels at S. Outputs are in the high-impedance state when the output-enable (OE) input is high.
All but one device must be in the high-impedance state to avoid currents exceeding the maximum ratings if outputs are tied together. OE inputs must ensure that there is no overlap when outputs of 3-state devices are tied together.
