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Quadruple 1-of-2 Data Selectors/Multiplexers with 3-State Outputs


Package | PIN: DBQ | 16
Temp: I (-40 to 85)
Carrier: Cut Tape
Qty Price
1-9 $1.21
10-24 $1.08
25-99 $1.00
100-249 $0.86
250-499 $0.79
500-749 $0.65
750-999 $0.52
1000+ $0.46


  • 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

Texas Instruments  CY74FCT257ATQCT

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.