CY74FCT257T是TI公司的一款解码器/编码器/多路复用器产品，CY74FCT257T是具有三态输出的四路 2 选 1 数据选择器/多路复用器，本页介绍了CY74FCT257T的产品说明、应用、特性等，并给出了与CY74FCT257T相关的TI元器件型号供参考。
CY74FCT257T - 具有三态输出的四路 2 选 1 数据选择器/多路复用器 - 解码器/编码器/多路复用器 - 特殊逻辑 - TI公司（Texas Instruments，德州仪器）
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.
- Function, Pinout, and Drive Compatible With FCT and F Logic
- Reduced VOH (Typically = 3.3 V) Version of Equivalent FCT Functions
- Edge-Rate Control Circuitry for Significantly Improved Noise Characteristics
- Ioff Supports Partial-Power-Down Mode Operation
- Matched Rise and Fall Times
- Fully Compatible With TTL Input and Output Logic Levels
- ESD Protection Exceeds JESD 22
- 2000-V Human-Body Model (A114-A)
- 200-V Machine Model (A115-A)
- 1000-V Charged-Device Model (C101)
- 64-mA Output Sink Current 32-mA Output Source Current
- 3-State Outputs
