This document describes the features and characteristics of the CD74AC257, CD74ACT257, and CD74ACT258 products from Harris Semiconductor, including non-inverting outputs, buffered inputs, typical propagation delay, exceeding 2kV ESD protection, SCR-Latchup-Resistant CMOS process and circuit design, fast speed with significantly reduced power consumption, balanced propagation delays, AC types with 1.5V to 5.5V operation and 30% supply noise immunity, ±24mA output drive current, etc.
The document describes the CD74AC257, CD74ACT257, and CD74ACT258 devices as quad 2-input multiplexers utilizing Harris Advanced CMOS Logic technology. These devices select four bits of data from two sources under the control of a common Select input (S) and feature active LOW Output Enable (OE). They are designed for applications such as moving data between registers to common output buses or acting as function generators.
| Typical Propagation Delay (In to Y) | 4.4ns at VCC = 5V, TA = 25°C, CL = 50pF |
|---|---|
| ESD Protection | Exceeds 2kV MIL-STD-883, Method 3015 |
| Output Drive Current | ±24mA |
| Supply Voltage Range (AC Types) | 1.5V to 5.5V |
| Operating Temperature Range | -55°C to 125°C |
The OE is active LOW; when OE is HIGH, all outputs are in the high-impedance state regardless of other input conditions.
Yes, the CD74AC257, CD74ACT257 and CD74ACT258 can also be used as function generators.
The maximum junction temperature for a plastic package is 150°C.