Texas Instruments SN74AHCT244DBRG4

Overview

SN74AHCT244DBRG4 from Texas Instruments is an octal 3-state buffer/driver IC designed for bus interface and memory address driving in 5-V digital systems. It features TTL-compatible inputs (VIH = 2 V, VIL = 0.8 V), ±8-mA output drive, 5.5-V absolute max supply rating, and operates from –40°C to 85°C. It enables bidirectional signal isolation in PC motherboard data buses and industrial I/O expansion modules.

For engineers reviewing the SN74AHCT244DBRG4 datasheet, SN74AHCT244DBRG4 pinout, SN74AHCT244DBRG4 application, or SN74AHCT244DBRG4 equivalent, key selection criteria include 3-state control timing (tPZH ≤ 12 ns), input voltage compatibility with legacy 3.3-V logic, thermal resistance (RθJA = 87.2°C/W in SSOP), and latch-up immunity (>250 mA per JESD17).

Technical Context

The SN74AHCT244DBRG4 implements two independent 4-bit noninverting buffers, each with dedicated 3-state output-enable (1OE, 2OE) inputs. Its CMOS design ensures rail-to-rail output swing (VOH ≥ 3.8 V at IOH = –8 mA, VOL ≤ 0.44 V at IOL = 8 mA) while maintaining TTL-level input thresholds.

It supports voltage translation from 3.3-V logic domains to 5-V buses without level shifters, thanks to VIH = 2 V and overvoltage-tolerant inputs (up to 5.5 V). Output edge rates are intentionally slowed to suppress ringing on unterminated transmission lines.

Key Specifications

Pinout & Package

SN74AHCT244DBRG4 is packaged in a 20-pin SSOP (Shrink Small Outline Package) with 0.65-mm lead pitch, body size 7.50 mm × 5.30 mm, and JEDEC MO-153 compliant footprint.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal 3-state buffer applications.

Compared with SN74AHCT244PW and 74LVC244APW, SN74AHCT244DBRG4 provides superior thermal performance in 5-V bus applications, direct TTL compatibility without level shifters, and guaranteed operation across the full industrial temperature range - making it optimal for legacy system upgrades and mixed-voltage backplanes.

Availability

SN74AHCT244DBRG4 is available at Aetrix Electronics and suitable for PC motherboard I/O expansion, industrial PLC backplane interface, and wearable health data aggregation requiring stable component supply and long-term production continuity.

Supply support for SN74AHCT244DBRG4 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader delivering analog and embedded processing solutions, with over 90 years of innovation in logic, power, and signal chain technologies.

The SN74AHCT244 family was engineered for robust 5-V bus interfacing in mixed-signal systems, emphasizing noise immunity, TTL compatibility, and fail-safe 3-state control - targeting industrial control, computing infrastructure, and test equipment.

FAQ

What is the maximum operating temperature for SN74AHCT244DBRG4?

The SN74AHCT244DBRG4 is rated for operation from –40°C to +85°C. This temperature range is validated per the manufacturer's recommended operating conditions and applies specifically to the DB (SSOP-20) package variant. Thermal derating is not required within this span, and the device maintains full electrical specifications across the entire range.

Does SN74AHCT244DBRG4 support 3.3-V input logic levels?

Yes, SN74AHCT244DBRG4 accepts 3.3-V logic inputs reliably: its VIH(min) = 2.0 V and VIL(max) = 0.8 V are fully compatible with standard 3.3-V CMOS/TTL outputs. Inputs are overvoltage tolerant up to 5.5 V, allowing safe interfacing even when driven before VCC is stable.

What is the purpose of the two OE pins on SN74AHCT244DBRG4?

SN74AHCT244DBRG4 has two independent output-enable pins (1OE and 2OE) controlling two groups of four buffers each. This allows selective 3-state control - for example, enabling only the lower nibble while holding the upper nibble in high-impedance - essential for partial bus arbitration and multi-master communication protocols.

Can SN74AHCT244DBRG4 drive a 50-pF load at 10-MHz frequency?

Yes. At CL = 50 pF and VCC = 5 V, SN74AHCT244DBRG4 delivers tPLH/tPHL ≤ 9.5 ns and tPZH ≤ 13 ns, supporting reliable 10-MHz toggling with >5 ns setup/hold margin. The slow edge rate further ensures minimal overshoot on such loads without external termination.

Is SN74AHCT244DBRG4 RoHS-compliant and lead-free?

Yes, SN74AHCT244DBRG4 is RoHS-compliant and features NiPdAu (NIPDAU) lead finish. It meets JEDEC Level-1 moisture sensitivity (260°C peak reflow) and is supplied in tape-and-reel packaging (2000 units/reel) with Q1 pin-1 quadrant orientation.