Texas Instruments SN74LV240ADW

Overview

SN74LV240ADW from Texas Instruments is an octal inverting buffer/driver with 3-state outputs, designed for 2V–5.5V V_CC operation. It features dual 4-bit sections with independent output-enable (OE) inputs, 6.5ns max propagation delay at 5V, 16mA output drive at 4.5V, and I_off support for live insertion-used in memory address buffering and bus isolation in network switches.

For engineers reviewing the SN74LV240ADW datasheet, SN74LV240ADW pinout, SN74LV240ADW application, or SN74LV240ADW equivalent, key selection criteria include its 20-pin SOIC (DW) package, 3-state inversion logic, mixed-voltage interface capability, and verified 125°C operating temperature range.

Technical Context

The SN74LV240ADW implements two independent 4-bit inverting buffers, each controlled by a dedicated OE input (1OE on Pin 1, 2OE on Pin 19). When OE is low, inverted data passes from A-inputs to Y-outputs; when high, outputs enter high-impedance state-enabling bidirectional bus control without external direction logic.

It supports mixed-mode voltage operation: inputs tolerate up to 5.5V regardless of V_CC, enabling level translation from 5V systems to 3.3V or 2.5V domains. The I_off feature ensures negligible power-off leakage (<5 µA) and prevents back-drive damage during partial power-down sequences.

Key Specifications

Pinout & Package

SN74LV240ADW uses a 20-pin SOIC (DW) package measuring 12.80 mm × 10.3 mm (body: 12.80 mm × 7.50 mm), with standard 0.050″ (1.27 mm) lead pitch and gull-wing leads compatible with IPC-7351B SOIC-20 footprint.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal inverting buffer applications.

Compared with SN74LV240ADW, SN74LVC240APWR offers faster timing and lower voltage operation but sacrifices 5.5V input tolerance, while 74LVX240M provides functional equivalence at reduced drive strength and uncertain supply chain longevity.

Availability

SN74LV240ADW is available at Aetrix Electronics and suitable for memory address buffering, network switch bus isolation, wearable sensor hub interfaces, and industrial PLC I/O expansion requiring stable component supply across automotive, industrial, and communications end markets.

Supply support for SN74LV240ADW 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 ICs for industrial and communications infrastructure.

The SN74LV240A product line was developed to deliver high-density, low-power 3-state buffering for memory, clock, and bus applications-specifically targeting space-constrained, mixed-voltage systems in networking and embedded control.

FAQ

What is the maximum operating temperature for SN74LV240ADW?

The SN74LV240ADW is rated for operation from –40°C to +125°C ambient temperature, validated per TI's thermal characterization data (R_θJA = 79.2°C/W for DW package). This specification applies to continuous operation under recommended conditions and supports deployment in industrial-grade network switches and motor control cabinets where ambient temperatures exceed 85°C.

Does SN74LV240ADW support 5V input signals while operating at 3.3V V_CC?

Yes, SN74LV240ADW supports input voltages up to 5.5V regardless of V_CC level, confirmed in Section 5.3 (Recommended Operating Conditions) and Section 7.3 (Feature Description) of the datasheet. This allows direct interfacing of 5V sensors or legacy peripherals to a 3.3V system without external level-shifting circuitry-verified for both static and dynamic (VIH(D)/VIL(D)) conditions.

What is the output drive capability of SN74LV240ADW at 3.3V V_CC?

At V_CC = 3.3V, SN74LV240ADW delivers ±8mA output current (I_OH/I_OL) per pin, as specified in Table 5.3. This enables reliable driving of 10 LVTTL loads or 3–4 CMOS inputs while maintaining VOL ≤ 0.44V and VOH ≥ 2.48V-critical for noise margin preservation in dense PCB layouts with distributed capacitive loads.

Is SN74LV240ADW pin-compatible with other packages in the SN74LV240A family?

No-SN74LV240ADW (SOIC-20) shares identical pin functions and logic behavior with SN74LV240ADBR (SSOP), SN74LV240ADGVR (TVSOP), and others per Table 4-1, but mechanical dimensions, thermal resistance, and soldering profiles differ. While electrical pinout is consistent, PCB layout must be redesigned for each package type due to distinct land patterns and body sizes.

How does the I_off feature function in SN74LV240ADW during power-down sequences?

The I_off circuitry in SN74LV240ADW limits input/output leakage to <5 µA when V_CC = 0V, preventing current backflow from powered sections into unpowered ones. This is explicitly tested per Section 5.5 (Electrical Characteristics) and enables safe live insertion of daughterboards or modular line cards in systems where partial power-down occurs-without requiring external isolation diodes or FETs.