Device identity and key parametrics
The SN74HCT157D is a 4 x 2:1 multiplexer from Texas Instruments' 74HCT logic family, packaged in a 16-SOIC (0.154", 3.90mm Width) surface-mount package. Output drive capability is 6mA source and 6mA sink, typical for HCT-series logic at 5V.
The 16-SOIC package (body width 3.90mm, pitch 1.27mm) is a standard JEDEC outline — the footprint matches any SOIC-16 land pattern and reflow profile common to 74HCT logic. No exposed pad or thermal slug; the part is convection-cooled through the leads and board copper. The tube packaging suits automated pick-and-place but also bench prototyping.