CY74FCT257T中文资料具有三态输出的四路 2 选 1 数据选择器/多路复用器数据手册TI规格书

描述 Description

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. This device is fully specified for partial-power-down applications using Ioff. The Ioff circuitry disables the outputs, preventing damaging current backflow through the device when it is powered down.

特性 Features

• Function, Pinout, and Drive Compatible With FCT and F Logic
• Edge-Rate Control Circuitry for Significantly Improved Noise Characteristics
• Matched Rise and Fall Times
• ESD Protection Exceeds JESD 22
• 200-V Machine Model (A115-A)
• 64-mA Output Sink Current 32-mA Output Source Current
• 3-State Outputs