Texas Instruments SN74LV540ANSR

Overview

SN74LV540ANSR from Texas Instruments is an octal inverting buffer/driver with 3-state outputs, designed for bus line driving and memory address register buffering in 2 V to 5.5 V systems. It features dual active-low output enables (OE1, OE2), supports mixed-mode voltage operation, provides I_off for partial-power-down mode, and delivers ≤8.5 ns propagation delay at 5 V.

For engineers reviewing the SN74LV540ANSR datasheet, SN74LV540ANSR pinout, SN74LV540ANSR application, or SN74LV540ANSR equivalent, this device is selected for low-ringing bus interfacing in industrial transports, patient monitoring, and wireless infrastructure where controlled edge rates, 3-state bus isolation, and wide-V_CC compatibility are required.

Technical Context

The SN74LV540ANSR implements eight independent inverting buffers, each with a two-input AND gate control logic for 3-state enable: outputs enter high-impedance when either OE1 or OE2 is high. Inputs tolerate up to 5.5 V regardless of V_CC, enabling down-translation from higher-voltage logic domains.

Its low-drive CMOS architecture produces slow edge rates (20 ns/V min at 5 V) to suppress output ringing and undershoot/overshoot-verified by typical VOHV >2.3 V and VOLP <0.8 V at 3.3 V. Thermal performance is characterized across multiple packages, with R_θJA = 77.1°C/W for the NS (SOP-20) variant.

Key Specifications

Pinout & Package

SN74LV540ANSR uses a 20-pin SOP (Small Outline Package) with 12.6 mm × 5.3 mm body size and standard 0.65 mm lead pitch. Pin 1 is located at the top-left corner adjacent to the index notch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC540APWR and 74ACT540SCX, SN74LV540ANSR uniquely balances wide V_CC operation, input overvoltage tolerance, and controlled edge rates-making it the only option among the three qualified for mixed-voltage industrial and automotive bus isolation with safe partial-power-down behavior.

Availability

SN74LV540ANSR is available at Aetrix Electronics and suitable for industrial transports, patient monitoring, and wireless infrastructure requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74LV540ANSR 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 connectivity technologies with over 50 years of innovation in industrial, automotive, and communications markets.

The SN74LV540ANSR belongs to TI's LV family of low-voltage logic devices, engineered for robust mixed-signal interfacing in harsh environments where voltage translation, ESD resilience, and thermal stability are critical design requirements.

FAQ

What is the function of OE1 and OE2 on the SN74LV540ANSR?

The SN74LV540ANSR uses two active-low output enable inputs (OE1 and OE2) connected to a two-input AND gate controlling all eight outputs. If either OE1 or OE2 is high, all Y1–Y8 outputs enter high-impedance state. Both must be low for normal inverted buffering. This dual-enable structure allows flexible bus arbitration and group-level control in multi-peripheral systems.

Does the SN74LV540ANSR support 5 V inputs while operating at 3.3 V V_CC?

Yes, the SN74LV540ANSR supports input voltages up to 5.5 V regardless of V_CC level, enabling reliable down-translation from 5 V controllers to 3.3 V buses. This capability is explicitly verified in the datasheet's Recommended Operating Conditions and Feature Description sections, making SN74LV540ANSR suitable for mixed-voltage system interfacing without external level shifters.

What is the maximum output current per pin for the SN74LV540ANSR?

The SN74LV540ANSR specifies ±16 mA maximum output current per pin at V_CC = 4.5–5.5 V, with total device current limited to ±70 mA. At 3.3 V, the rated output current is ±8 mA per pin. These values are confirmed in Section 6.3 (Recommended Operating Conditions) and Table 6-5 (Electrical Characteristics), ensuring safe drive capability for standard CMOS and TTL loads.

How does the SN74LV540ANSR minimize output ringing in high-speed bus applications?

The SN74LV540ANSR minimizes output ringing through intentional low-drive strength and slow edge rates-specified as minimum 20 ns/V input transition rate at 5 V. Its typical VOLP <0.8 V and VOHV >2.3 V at 3.3 V confirm suppressed ground bounce and undershoot. These characteristics are validated in Sections 1 (Features) and 6.9 (Noise Characteristics), making SN74LV540ANSR ideal for unterminated or stub-loaded bus traces.

Is the SN74LV540ANSR compatible with partial-power-down operation?

Yes, the SN74LV540ANSR includes I_off circuitry that limits leakage current to ≤5 µA when V_CC = 0 V, allowing safe connection to live buses during power sequencing. This feature is documented in Section 1 (Features), Section 8.3 (Feature Description), and Table 6-5 (Electrical Characteristics), confirming its suitability for hot-swap and modular power architectures where subsystems power up/down independently.