Texas Instruments SN74LVC157AD

Overview

SN74LVC157AD from Texas Instruments is a quadruple 2-line to 1-line data selector/multiplexer in 16-pin SOIC package, operating from 1.65V to 3.6V supply, with 5.2ns max propagation delay at 3.3V, 5.5V-tolerant inputs, and –40°C to 125°C temperature range. It serves as a high-speed digital signal routing IC in bus multiplexing, data path selection, and logic-level translation applications.

For engineers reviewing the SN74LVC157AD datasheet, SN74LVC157AD pinout, SN74LVC157AD application, or SN74LVC157AD equivalent, key selection criteria include its 16-pin SOIC (D) package compatibility, true-output logic architecture, 5.5V input tolerance enabling mixed-voltage interfacing, and guaranteed operation across industrial and extended temperature ranges.

Technical Context

The SN74LVC157AD implements four independent 2:1 multiplexers sharing a common active-low output strobe (G) and address select (A/B) control. Each channel selects between two data inputs (e.g., 1A/1B) and routes the chosen signal to its corresponding output (1Y), with all outputs forced low when G is high.

Its CMOS design supports 1.65V–3.6V V_CC, accepts 0–5.5V input voltages regardless of supply level, and delivers rail-to-rail output swing. The device exhibits low ground bounce (<0.8V) and undershoot (>2V) at 3.3V, ensuring signal integrity in high-speed digital systems.

Key Specifications

Pinout & Package

SN74LVC157AD uses a 16-pin SOIC (D) package with 9.90 mm × 6.00 mm body size and standard 1.27 mm pitch. Pin 1 is top-left corner (A/B), pin 8 is GND, pin 16 is V_CC, and pin 15 is active-low output enable (G).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multiplexer applications.

Compared with SN74LVC157ADR and 74LVC157PW, the SN74LVC157AD offers optimal balance of ease of prototyping (tube packaging), SOIC hand-solderability, and thermal performance (R_θJA = 118.1°C/W), making it ideal for evaluation, low-volume builds, and industrial control modules where mechanical robustness matters.

Availability

SN74LVC157AD is available at Aetrix Electronics and suitable for bus multiplexing, data path selection, logic-level translation, and address decoding applications requiring stable component supply across automotive, industrial, and communications equipment lifecycles.

Supply support for SN74LVC157AD 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 high-reliability electronic components.

The SN74LVC157AD belongs to TI's LVC (Low-Voltage CMOS) logic family, engineered for low-power, high-speed digital interfacing in mixed-voltage systems where signal integrity and wide operating margins are critical.

FAQ

What is the maximum clock/data rate supported by the SN74LVC157AD?

The SN74LVC157AD does not operate on a clock; it is a combinational multiplexer. Its maximum usable data rate is determined by propagation delay: at 3.3V, t_pd ≤ 5.2ns, supporting clean signal transitions up to ~100MHz for single-bit edges. For reliable 4-bit parallel data routing, system timing must account for worst-case skew across all four channels within the SN74LVC157AD.

Can the SN74LVC157AD safely interface a 5V microcontroller with a 3.3V FPGA?

Yes. The SN74LVC157AD accepts input voltages up to 5.5V regardless of V_CC level, so 5V logic signals from the microcontroller can directly drive its A/B, G, and data inputs while V_CC = 3.3V. Its outputs swing rail-to-rail (0V to 3.3V), making them fully compatible with 3.3V FPGA I/O standards.

Does the SN74LVC157AD require external pull-up or pull-down resistors on unused inputs?

Yes. Per TI's SCBA004 guidance, all unused inputs of the SN74LVC157AD-including A/B, G, and any unconnected 1A/1B/2A/etc.-must be tied to V_CC or GND. Floating inputs cause increased ICC, noise susceptibility, and potential oscillation; tying to V_CC is typical for active-high controls like A/B, while G (active-low) is often pulled high via resistor.

What is the thermal performance of the SN74LVC157AD in its SOIC package?

The SN74LVC157AD in SOIC (D) package has a junction-to-ambient thermal resistance (R_θJA) of 118.1°C/W. At 500mW max power dissipation and 25°C ambient, junction temperature reaches ~61°C-well within its 125°C rating. For sustained high-load operation, add copper pour under pin 8 (GND) and ensure ≥1 cm² of 2-oz copper on inner layers.

How does the G (strobe) pin function in the SN74LVC157AD?

The G pin is an active-low output enable: when G = HIGH, all four Y outputs are forced LOW regardless of A/B state or input values; when G = LOW, the multiplexer operates normally, routing selected inputs (A or B per channel) to their respective Y outputs. This allows synchronized blanking of all outputs during bus arbitration or reset sequences in the SN74LVC157AD.