5V bus buffer with asymmetric drive — what the 32 mA / 64 mA split means
The Texas Instruments SN74ABT126RGYR is a 74ABT-series quad buffer with non-inverting logic and 3-state outputs, each element handling one bit. The 3-state control lets you float the outputs for shared bus architectures where multiple drivers talk to the same line. With four independent buffers in a single 14-VFQFN package (3.5x3.5 mm), it saves board area compared to four discrete SOIC-8 buffers.
The 5 V ± 0.5 V supply range is a direct fit for legacy 5 V TTL backplanes and 5 V-only microcontroller buses; it does not tolerate 3.3 V or 1.8 V rails without a level translator.
Package and footprint — the exposed pad matters
Without the via stitch, junction temperature rises faster under continuous 64 mA sink per channel — the pad is the primary thermal path. The small footprint is a win for dense PCB layouts, but the pad's solder paste coverage needs to be controlled to avoid voiding or tombstoning during reflow.