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 I_off. The I_off 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

• Technology Family
• FCT
• Function
• Digital Multiplexer
• Configuration
• 2:1
• Number of channels (#)
• 4
• Operating temperature range (C)
• -40 to 85
• Rating
• Catalog

CY74FCT257T的完整型号有：CY74FCT257ATD、CY74FCT257ATQCT、CY74FCT257CTSOC、CY74FCT257TQCT，以下是这些产品的关键参数及官网采购报价：

CY74FCT257ATD，工作温度：-40 to 85，封装：SOIC (D)-16，包装数量MPQ：40个，MSL 等级/回流焊峰值温度：Level-1-260C-UNLIM，引脚镀层/焊球材料：NIPDAU，TI官网CY74FCT257ATD的批量USD价格：.288（1000+）

CY74FCT257ATQCT，工作温度：-40 to 85，封装：SSOP (DBQ)-16，包装数量MPQ：2500个，MSL 等级/回流焊峰值温度：Level-2-260C-1 YEAR，引脚镀层/焊球材料：NIPDAU，TI官网CY74FCT257ATQCT的批量USD价格：.432（1000+）

CY74FCT257CTSOC，工作温度：-40 to 85，封装：SOIC (DW)-16，包装数量MPQ：40个，MSL 等级/回流焊峰值温度：Level-1-260C-UNLIM，引脚镀层/焊球材料：NIPDAU，TI官网CY74FCT257CTSOC的批量USD价格：.288（1000+）

CY74FCT257TQCT，工作温度：-40 to 85，封装：SSOP (DBQ)-16，包装数量MPQ：2500个，MSL 等级/回流焊峰值温度：Level-2-260C-1 YEAR，引脚镀层/焊球材料：NIPDAU，TI官网CY74FCT257TQCT的批量USD价格：.432（1000+）

14-24-LOGIC-EVM — 支持 14 到 24 引脚 PW、DB、D、DW、NS、DYY 和 DGV 封装的通用逻辑 EVM

该 EVM 设计用于支持采用 14 至 24 引脚 D、DW、DB、NS、PW、DYY 或 DGV 封装的任何逻辑器件。