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)
CY54FCT157T
32-mA Output Sink Current
12-mA Output Source Current
CY74FCT157T
64-mA Output Sink Current
32-mA Output Source Current
3-State Outputs
The \x92FCT157T 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\) input is active low. When E\ 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 \x92FCT157T 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 \x92FCT157T 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 Ioff. The Ioff circuitry disables the outputs, preventing damaging current backflow through the device when it is powered down.