The 74AC257 is an advanced high-speed CMOS QUAD 2-CHANNEL MULTIPLEXER (3-STATE) fabricated with sub-micron silicon gate and double-layer metal wiring C2MOS tecnology. It is composed of four independent 2-channel multiplexer with common SELECT and ENABLE (OE) inputs. It is a non-inverting multiplexer. When the OE input is held HIGH,all the output become in