16-bit bus buffer — what the 32/64 mA drive means on a loaded backplane
The headline number is the output drive: 32 mA source, 64 mA sink per channel. That sink current is what keeps the low-level noise margin on a heavily loaded backplane or memory-array bus; a standard 74ABT octal buffer typically sources and sinks the same 32 mA, so the 64 mA sink here buys you an extra half volt of noise margin on the falling edge when driving 50 pF plus trace capacitance.
48-pin SSOP — footprint and rework realities
The SN74ABTH16244DL comes in a 48-BSSOP body (0.295" wide, 7.50 mm), also referred to as 48-SSOP. That is a fine-pitch (0.635 mm) surface-mount package. The SSOP leads are delicate — one bent pin during desoldering and the board is scrap unless you have a hot-air station with a fine nozzle.