CD74HCT257中文资料具有同向三态输出的高速 CMOS 逻辑四路 2 输入多路复用器数据手册TI规格书

描述 Description

The ’HC257 and ’HCT257 are quad 2-input multiplexers which select four bits of data from two sources under the control of a common Select Input (S). The Output Enable input (OE\\) is active LOW. When OE\\ is HIGH, all of the outputs (1Y-4Y) are in the high impedance state regardless of all other input conditions.
Moving data from two groups of registers to four common output buses is a common use of the 257. The state of the Select input determines the particular register from which the data comes. It can also be used as a function generator.

特性 Features

• Buffered Inputs
• Typical Propagation Delay (In to Output) = 12ns at VCC = 5V, CL = 15pF, TA = 25°C
• Bus Driver Outputs...15 LSTTL Loads
• Balanced Propagation Delay and Transition Times
• HC Types
• High Noise Immunity: NIL = 30%, NIH = 30% of VCC at VCC = 5V
• Direct LSTTL Input Logic Compatibility, VIL = 0.8V (Max), VIH = 2V (Min)
• CMOS Input Compatibility, Il 1µA at VOL, VOH
Data sheet acquired from Harris Semiconductor