Device type and logic family
The CD74HC157MT is a quad 2:1 multiplexer from the 74HC high-speed CMOS logic family. It selects one of two 4-bit data inputs under control of a common select line, routing the chosen nibble to the output bus. Operating from a single 2V to 6V supply, the device is compatible with TTL-level inputs while drawing the low quiescent current characteristic of CMOS.
Output drive and signal integrity
Symmetric output drive of 5.2 mA source and 5.2 mA sink at the rated supply voltage. This drive strength is sufficient for driving one or two standard CMOS loads on a short PCB trace; for longer backplane runs or higher fan-out, a buffer stage should follow the multiplexer output. The single independent circuit (one multiplexer per package) means the entire IC is one functional block. There are no unused gates to terminate; the select and enable inputs should be tied to VCC or GND through a pull resistor if left unused to prevent floating input current draw.
The CD74HC157MT is the tape-and-reel variant of the base CD74HC157M. The die and package are identical; the suffix T denotes the reel packaging for automated pick-and-place. A BOM specifying the M suffix can accept the MT variant without a board spin, provided the reel quantity matches the production volume.