描述 Description

The Harris CD74HC157, CD74HCT157, CD74HC158 and CD74HCT158 are quad 2-input multiplexers which select four bits of data from two sources under the control of a common Select input (S). The Enable input (E) is active Low. When (E) is High, all of the outputs in the 158, the inverting type, (1Y-4Y) are forced High and in the 157, the noninverting type, all of the outputs (1Y-4Y) are forced Low, regardless of all other input conditions.

特性 Features

? Common Select Inputs

? Separate Enable Inputs

? Buffered inputs and Outputs

? Fanout (Over Temperature Range)

- Standard Outputs . . . . . . . . . . . . . . . 10 LSTTL Loads

- Bus Driver Outputs . . . . . . . . . . . . . 15 LSTTL Loads

? Wide Operating Temperature Range . . . -55°C to 125°C

? Balanced Propagation Delay and Transition Times

? Significant Power Reduction Compared to LSTTL Logic ICs

? HC Types

- 2V to 6V Operation

- High Noise Immunity: NIL = 30, NIH = 30of VCC at VCC = 5V

? HCT Types

- 4.5V to 5.5V Operation

- Direct LSTTL Input Logic Compatibility, VIL= 0.8V (Max), VIH = 2V (Min)

- CMOS Input Compatibility, Il ≤ 1μA at VOL, VOH