Bus buffer for 5V backplanes and memory interfaces
The SN74ABT2244ADWR is a dual 4-bit non-inverting buffer from the 74ABT family — the 2-element, 4-bit-per-element organization maps directly to an 8-bit bus split across two byte lanes, or two independent 4-bit control signal groups. The 3-state outputs let multiple drivers share a bus without contention; the OE pin per element gates the outputs independently.
Output drive and fan-out at 5 V
The 32 mA output high / 12 mA output low current rating sets the practical fan-out: at 5 V, each output can drive about 10 standard LSTTL loads (2.6 mA per load) or 20 74ABT inputs (1.5 mA per load) while staying within the drive capability. The asymmetric high/low drive matches the typical bus load where the high-level current demand is higher due to pull-up terminations. For a 50 pF bus trace at 50 MHz, the 32 mA source delivers a 10-90 % rise time around 2 ns — fast enough for synchronous buses running up to 100 MHz but not so aggressive that it rings on poorly terminated backplanes. The output impedance is roughly 12 Ω in the high state, which helps damp reflections when the trace impedance is 50-60 Ω.
SOIC-20 layout and tape-and-reel logistics
The 20-SOIC wide-body package (7.50 mm body width, 1.27 mm pitch) is a standard footprint that routes easily on 2-layer boards — the 0.295-inch width gives room for a via between pads. The supplier device package is 20-SOIC; the land pattern matches JEDEC MS-013. RoHS3 compliant per, no exemptions that complicate EU or California compliance.
Availability and current pricing confirmed at RFQ time — no stock-holding claim, sourced per request. The TR reel is the standard production format; CT cut tape available for smaller quantities.