The CY74FCT2257T 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 appears at the output in noninverted form for the CY74FCT2257T. On-chip termination resistors at the outputs reduce system noise caused by reflections. The CY74FCT2257T can replace the FCT257T to reduce noise in an existing design.

The CY74FCT2257T is a logic implementation of a four-pole, two-position switch, in which the position of the switch is determined by the logic levels supplied to S. Outputs are forced to the high-impedance off state when the output-enable (OE\) input is high.

All but one device must be in the high-impedance state to prevent currents from exceeding the maximum ratings if outputs are tied together. Design of the OE\ signals 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 and Pinout Compatible With FCT and F Logic
• 25- Output Series Resistors to Reduce Transmission-Line Reflection Noise
• TTL Output Level Versions of Equivalent FCT Functions
• Edge-Rate Control Circuitry for Significantly Improved Noise Characteristics
• Ioff Supports Partial-Power-Down Mode Operation
• 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)
• 12-mA Output Sink Current 15-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

CY74FCT2257T的完整型号有：CY74FCT2257ATQCT，以下是这些产品的关键参数及官网采购报价：

CY74FCT2257ATQCT，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CY74FCT2257ATQCT的批量USD价格：1.116（1000+）