This document introduces the features and parameters of the 74F157A / 74F158A data selectors / multiplexers. It is a high speed quad 2-input multiplexer which selects 4 bits of data from one of two sources under the control of a common select input (S). When E is high, all of the outputs (Yn) are forced low regardless of all other input conditions. Moving data from two registers to a common output bus is a common use of the 74F157A. The state of the select input determines the particular register from which the data comes. The device is the logic implementation of a 4-pole, 2-position switch where the position of the switch is determined by the logic levels supplied to the select input. The 74F158A is similar, but has inverting outputs (Yn).
This document is a product specification for the Philips 74F157A and 74F158A, which are high-speed quad 2-input data selectors/multiplexers. The 74F157A features non-inverting outputs, while the 74F158A provides inverting outputs. Both devices select 4 bits of data from one of two sources under the control of a common Select input, with an active-low Enable input.
| Propagation Delay (Typical) | 4.6ns (74F157), 3.7ns (74F158) |
|---|---|
| Supply Current (Typical) | 15mA (74F157), 10mA (74F158) |
| Operating Temperature Range (Commercial) | 0°C to +70°C |
| Operating Temperature Range (Industrial) | -40°C to +85°C |
| Supply Voltage | 4.5V to 5.5V |
| High-Level Input Voltage | 2.0V |
| Low-Level Input Voltage | 0.8V |
| High-Level Output Current | -1mA |
| Low-Level Output Current | 20mA |
The 74F157A has non-inverting outputs, while the 74F158A has inverting outputs.
Each channel has two data inputs (I0n and I1n).
The Enable input is active when Low; when High, all outputs are forced Low.
No, the 74F157 and 74F158 parts are discontinued.