Texas Instruments SN74LV244APW

Overview

SN74LV244APW from Texas Instruments is an octal 3-state buffer/driver IC designed for bidirectional signal buffering in bus-oriented systems. It features dual 4-bit groups with independent output-enable (OE) controls, operates from 2 V to 5.5 V, delivers ≤6.5 ns propagation delay at 5 V, supports mixed-mode voltage operation, and includes Ioff for partial-power-down mode - used in server memory address buffering and industrial bus interface isolation.

For engineers reviewing the SN74LV244APW datasheet, SN74LV244APW pinout, SN74LV244APW application, or SN74LV244APW equivalent, key selection criteria include its 20-pin TSSOP package, 3-state drive capability up to ±16 mA per output, guaranteed operation across –40°C to +125°C, and compatibility with 2.5 V/3.3 V/5 V logic domains in high-density PCB layouts.

Technical Context

The SN74LV244APW implements two independent 4-bit non-inverting buffer sections, each with dedicated active-low output-enable inputs (1OE, 2OE). Its balanced CMOS 3-state outputs provide symmetrical sourcing and sinking (±16 mA at VCC = 4.5–5.5 V), enabling robust driving of capacitive loads ≤50 pF while maintaining fast edge integrity.

It integrates Ioff circuitry that disables all outputs when VCC = 0 V, limiting leakage to ≤5 µA per I/O, and features standard CMOS inputs with ≤2.3 pF input capacitance and rail-to-rail input voltage tolerance (0 to 5.5 V), supporting reliable interfacing with diverse logic families without level shifters.

Key Specifications

Pinout & Package

TSSOP-20 (PW) package: 6.50 mm × 7.8 mm body, 0.65 mm pitch, exposed pad optional (not electrically required), surface-mount compatible with standard reflow profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74LVC244APW and SN74AHCT244PW, the SN74LV244APW uniquely balances wide VCC range (2–5.5 V), guaranteed Ioff, and industrial temperature rating - making it the sole option for mixed-voltage, hot-pluggable, or extended-temperature embedded bus interfaces.

Availability

SN74LV244APW is available at Aetrix Electronics and suitable for server motherboard design, industrial motor-drive control boards, and telecom infrastructure requiring stable component supply across extended temperature and mixed-voltage conditions.

Supply support for SN74LV244APW 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 experience in high-reliability industrial and communications ICs.

The SN74LV244A belongs to TI's LV logic family, engineered for low-voltage operation (2–5.5 V), high noise immunity, and robust 3-state performance in dense, thermally constrained PCB environments like network switches and factory automation controllers.

FAQ

What is the maximum capacitive load the SN74LV244APW can drive while meeting datasheet timing specs?

The SN74LV244APW is characterized and guaranteed for loads ≤50 pF across all VCC and temperature conditions. At 50 pF and VCC = 5 V, its maximum propagation delay remains ≤6.5 ns. Driving larger loads increases tpd nonlinearly and may cause overshoot/undershoot beyond VOLP/VOHV limits - so 50 pF is the design target for full spec compliance in SN74LV244APW applications.

Does the SN74LV244APW support true 5 V-tolerant inputs when operated at 3.3 V VCC?

Yes. The SN74LV244APW accepts input voltages from 0 V to 5.5 V regardless of VCC setting - including when VCC = 3.3 V. This rail-to-rail input tolerance enables direct interfacing with 5 V peripherals without external level shifters, a confirmed feature documented in Section 6.3 (Recommended Operating Conditions) of the SN74LV244APW datasheet.

Can unused inputs on the SN74LV244APW be left floating?

No. All unused inputs on the SN74LV244APW must be terminated to either VCC or GND - never left floating. Floating CMOS inputs cause excessive current draw, oscillation, and potential device damage. TI explicitly mandates this in Section 6.3 Note (1) and Section 8.3.2, and recommends 10-kΩ pullup/pulldown resistors for uncommitted pins in SN74LV244APW designs.

What is the thermal resistance (RθJA) of the SN74LV244APW in its TSSOP-20 (PW) package?

The SN74LV244APW in the PW (TSSOP-20) package has a junction-to-ambient thermal resistance (RθJA) of 128.2°C/W, as specified in Section 6.4 Thermal Information of the official datasheet (SCLS383R, August 2023 revision). This value assumes standard JEDEC 2-layer board conditions and guides thermal design for continuous operation at rated current.

How does the Ioff feature of the SN74LV244APW behave during power-down sequences?

When VCC drops to 0 V, the Ioff circuitry in the SN74LV244APW actively disables all outputs, limiting leakage current to ≤5 µA per I/O pin - verified in Section 6.5 Electrical Characteristics. This prevents back-driving of powered sections and ensures safe partial-power-down behavior, a critical requirement validated for SN74LV244APW in hot-swap and battery-backed systems.