TI CY74FCT157CTQCT

The ’FCT157T devices are quad two-input multiplexers that select four bits of data from two sources under the control of a common data-select (S) input. The output-enable (E (overline)) input is active low. When E (overline) is high, all of the outputs (Y) are forced low, regardless of all other input conditions. Moving data from two groups of registers to four common output buses is a common use of the ’FCT157T devices. The state of S determines the particular register from which the data comes. It also can be used as a function generator. These devices are useful for implementing highly irregular logic by generating any 4 of the 16 different functions of 2 variables, with 1 variable common. The ’FCT157T devices are logic implementations of a four-pole, two-position switch, where the position of the switch is determined by the logic levels at S. These devices are 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 V₀ₕ (Typically = 3.3 V) Versions 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)
• 3-State Outputs