Texas Instruments SN74AHCT244PWR

Overview

SN74AHCT244PWR from Texas Instruments is an octal 3-state buffer/driver IC designed for bus interface and memory address driving in 5-V systems. It features TTL-compatible inputs (VIH = 2 V, VIL = 0.8 V), ±8 mA output drive, 5.5 ns typical propagation delay (CL = 15 pF), and operates from –40°C to +85°C. It enables level translation from 3.3-V logic to 5-V buses in PCs and network switches.

For engineers reviewing the SN74AHCT244PWR datasheet, SN74AHCT244PWR pinout, SN74AHCT244PWR application, or SN74AHCT244PWR equivalent, key selection criteria include 3-state bus contention control, input voltage compatibility with legacy TTL, low-output ringing due to controlled edge rates, and TSSOP-20 packaging for high-density PCB layouts.

Technical Context

The SN74AHCT244PWR 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) under 4.5–5.5 V supply operation.

It supports bidirectional bus isolation via high-impedance outputs when OE is high, and includes overvoltage-tolerant inputs (up to 5.5 V regardless of VCC). Latch-up immunity exceeds 250 mA per JESD17, and ESD robustness meets ±2000 V HBM/CDM standards.

Key Specifications

Pinout & Package

TSSOP-20 package (PW), 6.50 mm × 6.40 mm body size, 0.65 mm lead pitch, RoHS-compliant NIPDAU finish, MSL Level-1 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC244APWR and 74ACT244SCX, the SN74AHCT244PWR uniquely balances 5-V bus compatibility, TTL input acceptance, and low-power 3-state control - making it irreplaceable in mixed-voltage industrial control and legacy system upgrades.

Availability

SN74AHCT244PWR is available at Aetrix Electronics and suitable for network switches, PCs and notebooks, and power infrastructure applications requiring stable component supply, long-term manufacturability, and RoHS-compliant TSSOP packaging.

Supply support for SN74AHCT244PWR 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, embedded processing, and connectivity solutions for industrial, automotive, and consumer markets.

The SNx4AHCT244 product line delivers TTL-compatible, 3-state octal buffers optimized for bus isolation and level translation in 5-V digital systems - targeting reliability-critical control and interface applications.

FAQ

What is the maximum operating temperature for SN74AHCT244PWR?

The SN74AHCT244PWR is rated for operation from –40°C to +85°C ambient temperature. This range is specified in the Recommended Operating Conditions table and validated across production lots. The device uses standard CMOS process technology with thermal metrics including RθJA = 116.8°C/W (TSSOP-20), confirming suitability for enclosed industrial enclosures without forced airflow. Always verify board-level thermal design using actual power dissipation and layout.

Does SN74AHCT244PWR support 3.3-V input logic levels?

Yes, SN74AHCT244PWR explicitly supports 3.3-V input logic levels: its VIH threshold is 2.0 V (min) and VIL is 0.8 V (max), allowing reliable recognition of 3.3-V CMOS high/low states. This makes SN74AHCT244PWR ideal for translating 3.3-V signals to 5-V buses without external level shifters. Input pins are also overvoltage tolerant up to 5.5 V, enabling safe operation during mixed-voltage debug or hot-swap events.

What is the recommended bypass capacitor for SN74AHCT244PWR?

Texas Instruments recommends a 0.1 µF ceramic capacitor placed as close as possible to the VCC pin (Pin 20) of SN74AHCT244PWR. This value is specified in Section 8.2 of the datasheet to suppress high-frequency switching noise and maintain stable supply rail integrity. For boards with multiple power domains or high-current transients, paralleling a 1 µF capacitor is acceptable - but the 0.1 µF unit must remain adjacent to the IC's VCC pin to minimize inductance and ensure effective decoupling at >10 MHz frequencies.

Can SN74AHCT244PWR outputs be left floating when disabled?

No - SN74AHCT244PWR outputs enter high-impedance (3-state) mode when OE is high, which is electrically equivalent to floating. However, the datasheet (Section 8.3.1) mandates that *all unused inputs* be tied to VCC or GND to prevent undefined logic states and increased ICC. Outputs may float safely in high-Z mode, but system-level design must ensure no external pull-ups/pull-downs conflict with enabled outputs or cause contention during transitions. Floating outputs are acceptable only when fully isolated from other active drivers.

Is SN74AHCT244PWR pin-compatible with SN74AHCT244DW?

Yes, SN74AHCT244PWR and SN74AHCT244DW share identical pin functions and electrical behavior, as both belong to the SN74AHCT244 family and use the same 20-pin functional mapping (per Figure 4-1 and Table 4-1). However, they differ in package: PW is TSSOP-20 (6.5 mm × 6.4 mm), while DW is SOIC-20 (12.8 mm × 10.3 mm). PCB layout requires footprint redesign, but schematic symbol and net connectivity remain identical - enabling drop-in replacement at the circuit level with mechanical adaptation.