Texas Instruments SN74LVC157ANSR

Overview

SN74LVC157ANSR from Texas Instruments is a quadruple 2-line to 1-line data selector/multiplexer IC operating from 1.65V to 3.6V, supporting –40°C to 125°C temperature range, with 5.2ns max propagation delay at 3.3V, 5.5V-tolerant inputs, and 16-pin SOP package. It routes four independent 2:1 data paths under common address (A/B) and strobe (G) control in mixed-voltage digital systems.

For engineers reviewing the SN74LVC157ANSR datasheet, SN74LVC157ANSR pinout, SN74LVC157ANSR application, or SN74LVC157ANSR equivalent, this page delivers verified electrical specs, functional mode behavior, thermal metrics for NS package, real-world multiplexing use cases, and validated alternative parts - all grounded in TI's SCAS292S production datasheet (Dec 2024 revision).

Technical Context

The SN74LVC157ANSR implements true-output logic with active-low output enable (G), enabling simultaneous 4-bit word selection from two parallel sources. Its A/B input selects between corresponding A and B inputs per channel, while G forces all outputs low when high.

Designed for LVC-family voltage translation, it accepts 5.5V-tolerant inputs while operating on 1.65–3.6V V_CC, making it suitable for interfacing 3.3V logic with legacy 5V signal domains without level shifters. Input thresholds scale with V_CC (e.g., VIH = 0.65×V_CC at 1.65–1.95V), ensuring robust noise margins across supply voltages.

Key Specifications

Pinout & Package

SN74LVC157ANSR uses a 16-pin SOP (NS) package measuring 5.00 mm × 6.4 mm (body: 5.00 mm × 4.40 mm), with gull-wing leads and RoHS-compliant NiPdAu finish. Thermal resistance R_θJA = 64°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 4-channel 2:1 multiplexer applications.

Compared with SN74LVC157APWR, the SN74LVC157ANSR offers lower thermal resistance (64°C/W vs. 141.8°C/W) for better power handling in SOP layouts; versus SN74LVCH162374ADGGR, it provides simpler, faster combinatorial selection without latching overhead or increased pin count.

Availability

SN74LVC157ANSR is available at Aetrix Electronics and suitable for industrial control systems, automotive sensor interfaces, and FPGA I/O expansion requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for SN74LVC157ANSR 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 decades of experience in logic IC design and automotive-grade qualification.

The SN74LVC157ANSR belongs to TI's LVC (Low-Voltage CMOS) logic family, engineered for high-speed, low-power, mixed-voltage interoperability in industrial and automotive applications where reliability and voltage translation are critical.

FAQ

What is the maximum operating frequency supported by the SN74LVC157ANSR?

The SN74LVC157ANSR does not specify a maximum clock frequency, as it is a combinatorial device. Its speed is defined by propagation delay: 5.2ns max at 3.3V, supporting data switching up to ~100 MHz in well-designed layouts. Actual usable rate depends on input slew, load capacitance, and system timing margins - always validate with worst-case t_pd values from the SN74LVC157ANSR datasheet.

Can the SN74LVC157ANSR safely interface a 5V microcontroller with a 3.3V FPGA?

Yes. The SN74LVC157ANSR accepts 5.5V-tolerant inputs while operating from a 3.3V V_CC, making it ideal for bidirectional voltage translation. When used to route signals from a 5V MCU to a 3.3V FPGA, its outputs swing rail-to-rail (0V to 3.3V), meeting FPGA input thresholds. Ensure unused inputs are tied to V_CC or GND per TI's SCAS292S guidance to prevent floating nodes.

What is the thermal performance of the SN74LVC157ANSR in its SOP (NS) package?

The SN74LVC157ANSR in SOP (NS) package has a junction-to-ambient thermal resistance (R_θJA) of 64°C/W. At 3.3V and full 24mA per output, total power dissipation remains below 500mW up to 60°C ambient; above that, linear derating applies (5.5mW/K). For sustained operation, maintain adequate copper area and airflow - TI recommends 0.1µF bypassing at V_CC and grounding the thermal pad if present (though NS lacks exposed pad).

Does the SN74LVC157ANSR require external pull-up or pull-down resistors on control pins?

No. The SN74LVC157ANSR has CMOS inputs with negligible leakage (±5µA max), so external biasing is unnecessary if driven actively. However, TI mandates that all unused inputs - including G, A/B, and any unconnected data lines - be tied to V_CC or GND to prevent floating states that cause excessive ICC or undefined outputs. This requirement is explicitly stated in Section 4.4 of the SN74LVC157ANSR datasheet.

How does the output enable (G) pin function in the SN74LVC157ANSR?

The G pin on the SN74LVC157ANSR is an active-low output enable: when high, all four Y outputs are forced low regardless of A/B or data inputs; when low, the selected A or B inputs pass through to Y outputs. This enables time-multiplexed sharing of a common bus or prevents output contention during system reset - a key feature distinguishing it from basic 2:1 mux ICs without global enable.