Texas Instruments SN74AC244PWR

Overview

SN74AC244PWR from Texas Instruments is an octal 3-state buffer/driver IC designed for bus interface, memory address driving, and clock distribution in industrial and telecom systems. It operates from 2V to 6V V_CC, supports 5V/3.3V logic levels, delivers ≤7.5ns propagation delay at 5V, and features dual independent output-enable controls for flexible bus management in server backplanes and LED display controllers.

For engineers reviewing the SN74AC244PWR datasheet, SN74AC244PWR pinout, SN74AC244PWR application, or SN74AC244PWR equivalent, key selection criteria include its 20-pin TSSOP package, 3-state output architecture, wide supply range (2–6V), input tolerance up to 6V, and verified performance in high-density bus loading scenarios requiring low skew and fast enable/disable transitions.

Technical Context

The SN74AC244PWR implements two independent 4-bit non-inverting buffers, each with dedicated output-enable (1OE, 2OE) inputs controlling high-impedance states. Its AC logic family ensures compatibility with TTL and CMOS interfaces while maintaining rail-to-rail input voltage acceptance (up to 6V regardless of V_CC).

It supports bidirectional bus isolation via active-low OE control, exhibits symmetric t_PLH/t_PHL ≤7.5ns at 5V, and maintains stable output drive (±24mA) across its full operating temperature range (–40°C to +85°C), making it suitable for mixed-voltage signal routing in network switch fabric and motor-drive I/O expansion.

Key Specifications

Pinout & Package

TSSOP-20 (PW) package: 6.5mm × 4.4mm body size, 0.65mm pitch, exposed thermal pad (optional GND connection), RoHS-compliant NiPdAu lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC244APWR and 74ACT244PW, the SN74AC244PWR uniquely balances 5V/3.3V interoperability, low quiescent current (40µA), and industrial temperature support - making it the optimal choice for cost-sensitive, mixed-voltage industrial control boards requiring long-term supply stability.

Availability

SN74AC244PWR is available at Aetrix Electronics and suitable for server backplanes, LED display controllers, telecom line cards, and motor-drive I/O expansion requiring stable component supply across extended production lifecycles.

Supply support for SN74AC244PWR 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 over 90 years of innovation in industrial, automotive, and communications markets.

The SN74AC244PWR belongs to TI's AC logic family, engineered for high-speed, low-power bus interface applications where voltage flexibility, noise immunity, and 3-state control are critical in space-constrained industrial electronics.

FAQ

What is the maximum operating voltage for SN74AC244PWR?

The SN74AC244PWR supports a supply voltage range of 2V to 6V. Its absolute maximum rating is 7V on V_CC, but continuous operation above 6V is not recommended. Inputs tolerate up to 6V regardless of V_CC level - a key feature enabling safe interfacing with higher-voltage control signals without external protection circuitry. This specification is validated across the full –40°C to +85°C operating temperature range for the SN74AC244PWR.

Does SN74AC244PWR require external pull-up resistors on OE pins?

No, external pull-up resistors are not required on the OE pins of SN74AC244PWR for normal operation. The device functions correctly with OE driven actively low (to enable outputs) or high (to enter high-impedance state). However, during power-up/power-down sequences where OE may float, TI recommends tying OE to V_CC via a pull-up resistor (value determined by driver sink capability) to prevent undefined output states - a design practice confirmed in the SN74AC244PWR functional description section.

Can SN74AC244PWR drive 50pF loads at 10MHz?

Yes, SN74AC244PWR can reliably drive 50pF loads at 10MHz. Its specified power dissipation capacitance (C_pd) is 45pF per buffer at 1MHz, and switching characteristics (t_PLH/t_PHL ≤7.5ns at 5V) confirm adequate bandwidth. At 10MHz, total dynamic current remains within ±24mA output limits, and thermal data (R_θJA = 126.2°C/W) shows junction temperature rise stays within safe margins under typical PCB layout conditions - all verified in the SN74AC244PWR electrical and switching characteristics tables.

Is the thermal pad on SN74AC244PWR mandatory to connect?

The exposed thermal pad on SN74AC244PWR is not mandatory but strongly recommended for optimal thermal and mechanical performance. TI documentation specifies that the pad "must be soldered to the printed circuit board" for best results. Leaving it unconnected increases R_θJA by ~15°C/W and reduces mechanical reliability under thermal cycling. While functional operation is possible with the pad floating or tied to GND, full compliance with SN74AC244PWR thermal specifications requires soldering the pad to a dedicated thermal land.

How does SN74AC244PWR handle input signals exceeding V_CC?

SN74AC244PWR accepts input voltages up to 6V regardless of V_CC level - a documented feature enabling robust interfacing with higher-voltage peripherals. This is achieved through internal input protection structures that clamp voltages safely within absolute maximum ratings (–0.5V to V_CC+0.5V). When V_CC = 2V, inputs up to 6V remain within specification and do not activate internal clamps, eliminating risk of excessive IIK current. This behavior is explicitly guaranteed in the SN74AC244PWR Recommended Operating Conditions table.