Buffer with 3-state control — 32 mA high, 64 mA low output drive
The SN74ABT125DBR is a Texas Instruments 74ABT-series quad buffer with non-inverting logic and 3-state outputs, packaged in a 14-SSOP (0.209", 5.30 mm width) for surface-mount assembly. Each of the four elements handles one bit, with a separate output-enable pin per channel.
Output current rating — what 32/64 mA means for the load
The part sources 32 mA per output in the high state and sinks 64 mA in the low state. This asymmetric drive is typical of ABT logic: the stronger low-side sink handles the higher current of TTL-compatible inputs or LED loads, while the high-side source stays within the 32 mA limit to keep the output voltage within VOH specs. For a standard 5 V CMOS input drawing under 10 µA, the margin is generous; for a 50-Ohm terminated line, the 32 mA source delivers a 1.6 V swing into the load, which may not reach the VIH threshold of the receiver — a consideration when driving matched-impedance traces.
This includes uncontrolled indoor environments, telecom cabinets with passive cooling, and outdoor equipment in moderate climates. The 74ABT process maintains propagation delay and output skew across this range; the datasheet's typical and max timing figures at 25°C, 0°C, and 85°C should be reviewed for the specific operating point if the design runs near the temperature extremes.
14-SSOP package — footprint and assembly fit
The narrow body fits on a 2-layer board with reasonable fan-out; the 14 pins are all on the periphery, so no thermal pad or exposed paddle is present. Reflow profile follows standard JEDEC MSL-1 for the SSOP family — no special bake required before assembly if the tape-and-reel seal is intact.
Active lifecycle — sourcing posture for the BOM line
The 74ABT family is a mature BiCMOS logic series, so long-term availability is stable, but the 14-SSOP package in tape-and-reel format is the standard production variant — cut-tape orders for prototyping are also available per the packaging options.