Texas Instruments SN74ACT244DWR

Overview

SN74ACT244DWR from Texas Instruments is an octal 3-state non-inverting buffer/driver IC designed for bus-oriented data transmission, clock distribution, and memory address driving in 5-V digital systems. It features dual 4-bit channels with independent active-low output-enable (OE) controls, 24-mA output drive capability per channel, 9.5-ns maximum propagation delay at 5 V, and TTL-compatible inputs operating across 4.5 V to 5.5 V supply range.

For engineers reviewing the SN74ACT244DWR datasheet, SN74ACT244DWR pinout, SN74ACT244DWR application, or SN74ACT244DWR equivalent, key selection considerations include its SOIC-20 package compatibility, 3-state bus isolation behavior, high-current drive for LED or bus loading, and guaranteed operation over –40°C to +85°C industrial temperature range.

Technical Context

The SN74ACT244DWR implements two independent 4-bit buffer sections, each with dedicated active-low OE control (Pin 1 and Pin 19), enabling selective 3-state output gating without affecting the other channel. Its ACT logic family delivers bipolar-compatible speed and CMOS power efficiency, with input thresholds aligned to TTL levels (V_IL ≤ 0.8 V, V_IH ≥ 2.0 V at V_CC = 5 V).

Each output supports ±24 mA DC drive under recommended conditions, with VOL ≤ 0.44 V and VOH ≥ 3.76 V at V_CC = 4.5 V and I_OL/I_OH = 24 mA. The device exhibits low dynamic power dissipation (C_pd = 45 pF per buffer) and robust ESD tolerance (±3000 V HBM in DW package).

Key Specifications

Pinout & Package

SN74ACT244DWR is housed in a 20-pin SOIC (DW) package with 0.300-inch body width and standard 1.27-mm pitch. The package supports surface-mount reflow (MSL Level-1, 260°C peak) and provides mechanical stability for high-vibration industrial use cases.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LS244N and SN74HC244PW, SN74ACT244DWR uniquely balances TTL compatibility, 24-mA drive, and 9.5-ns speed within a 4.5–5.5-V window-making it optimal for industrial 5-V bus isolation where both performance and interoperability are critical.

Availability

SN74ACT244DWR is available at Aetrix Electronics and suitable for industrial control systems, telecom infrastructure equipment, and server motherboard designs requiring stable component supply, long-term lifecycle support, and RoHS-compliant SOIC packaging.

Supply support for SN74ACT244DWR 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 specializing in analog, embedded processing, and logic solutions, with decades of expertise in high-reliability interface and buffer ICs.

SN74ACT244DWR belongs to TI's ACT (Advanced CMOS TTL-compatible) logic family, engineered for high-speed, low-noise 5-V digital interfacing in demanding industrial and communications applications.

FAQ

What is the maximum output current rating for SN74ACT244DWR?

The SN74ACT244DWR is rated for ±24 mA DC output current per channel under recommended operating conditions (V_CC = 4.5 V to 5.5 V, T_A = –40°C to +85°C). This value is specified in the Electrical Characteristics table for I_OL and I_OH, and represents the guaranteed drive capability before VOL exceeds 0.44 V or VOH drops below 3.76 V. Exceeding this limit risks parametric shift or thermal stress.

Does SN74ACT244DWR support 3.3-V logic inputs?

No, SN74ACT244DWR does not reliably accept 3.3-V logic inputs. Its input thresholds are TTL-compatible (V_IL ≤ 0.8 V, V_IH ≥ 2.0 V at V_CC = 5 V), meaning a 3.3-V high signal falls within the undefined region and may cause inconsistent switching. For 3.3-V systems, consider level-shifting or selecting a 3.3-V–tolerant buffer such as SN74LVC244A instead of SN74ACT244DWR.

What is the function of Pins 1 and 19 on SN74ACT244DWR?

Pins 1 and 19 are the active-low output-enable inputs (1OE and 2OE) for the two independent 4-bit buffer sections of SN74ACT244DWR. When either pin is driven low, its associated group of four outputs (e.g., Pins 12, 14, 16, 18 for 1OE) passes non-inverted data from the corresponding A inputs. When high, those outputs enter high-impedance state. This enables precise bus arbitration and load isolation in multi-device systems using SN74ACT244DWR.

Can SN74ACT244DWR be used to drive LEDs directly?

Yes, SN74ACT244DWR can drive LEDs directly when used with appropriate current-limiting resistors. Each output supports up to 24 mA sink/source, allowing single-LED connections to V_CC (source mode) or GND (sink mode). For example, with V_CC = 5 V and a red LED (V_F ≈ 1.8 V), a 130-Ω resistor limits current to ~24 mA. Always verify LED forward voltage and thermal derating when operating multiple outputs simultaneously in SN74ACT244DWR.

What is the thermal resistance (RθJA) of SN74ACT244DWR in its SOIC package?

The junction-to-ambient thermal resistance (RθJA) for SN74ACT244DWR in the SOIC (DW) package is 101.2°C/W, as specified in Section 5.4 of the official datasheet. This value assumes standard JEDEC 2S2P test board conditions. Actual board-level RθJA will vary based on copper area, layer count, and airflow-but this baseline enables safe power dissipation estimation: at 24-mA drive across all eight outputs, total dynamic power remains well below thermal limits.