Texas Instruments SN74LVC257ANSR

Overview

SN74LVC257ANSR from Texas Instruments is a quadruple 2-line to 1-line data selector/multiplexer with 3-state outputs, designed for 1.65V–3.6V V_CC operation. It routes four independent 2-input data pairs to four outputs under select (A/B) and active-low output-enable (OE) control, supports 5.5V-tolerant inputs, achieves 4.6ns max propagation delay at 3.3V, and enables level translation in mixed-voltage bus systems such as I/O expanders and network switch control planes.

For engineers reviewing the SN74LVC257ANSR datasheet, SN74LVC257ANSR pinout, SN74LVC257ANSR application, or SN74LVC257ANSR equivalent, this page delivers verified functional mode behavior, confirmed SOP-16 package mapping, validated 3-state timing parameters, and real-world design implications for bus isolation and voltage translation in industrial and telecom infrastructure.

Technical Context

The SN74LVC257ANSR implements four independent 2:1 multiplexers sharing one A/B select line and one global OE input, each with CMOS-compatible 3-state outputs that present high impedance when OE = HIGH. Its logic-level translation capability stems from 5.5V-tolerant inputs operating across 1.65V–3.6V V_CC, enabling interface between legacy 5V logic and modern low-voltage controllers.

Functional modes are strictly defined by OE and A/B states: OE = HIGH forces all Y outputs into high-impedance regardless of A/B or data inputs; OE = LOW enables multiplexing where A/B = LOW selects A-inputs and A/B = HIGH selects B-inputs. No internal latching or clocking is present - it is purely combinational with no setup/hold timing dependencies beyond standard propagation delay.

Key Specifications

Pinout & Package

SOP-16 (NS) package: 5.00mm × 6.4mm body size, 16-pin surface-mount small-outline package with gull-wing leads, RoHS-compliant NiPdAu finish, MSL Level-1, rated for –40°C to +85°C ambient operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC157ADR and 74LVC257PW, the SN74LVC257ANSR offers identical functionality in the SOP-16 package - providing optimal balance of manufacturability, thermal performance (R_θJA = 64°C/W), and compatibility with standard pick-and-place tooling for mid-volume industrial production.

Availability

SN74LVC257ANSR is available at Aetrix Electronics and suitable for network switches, industrial PLCs, automated test equipment, and server BMC interfaces requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for SN74LVC257ANSR 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 logic families and industrial-grade interface ICs.

The SN74LVC257ANSR belongs to TI's LVC (Low-Voltage CMOS) logic family, engineered for robust operation across wide voltage ranges and mixed-signal environments in telecom, computing, and factory automation systems.

FAQ

What is the maximum input voltage the SN74LVC257ANSR can tolerate?

The SN74LVC257ANSR accepts input voltages up to 5.5V regardless of V_CC level - a key feature enabling direct interfacing with 5V logic in mixed-voltage systems. This tolerance is specified across the full operating temperature range (–40°C to +85°C) and does not require external clamping diodes or current-limiting resistors when driven within absolute maximum ratings.

Does the SN74LVC257ANSR support level translation between 1.8V and 5V domains?

Yes, the SN74LVC257ANSR supports bidirectional level translation: its inputs tolerate 5.5V while operating from V_CC = 1.65V–3.6V, and its outputs swing rail-to-rail within the V_CC domain. For example, with V_CC = 1.8V, it accepts 5V inputs and drives 1.8V-compatible outputs - making SN74LVC257ANSR ideal for bridging legacy and modern logic families.

What is the recommended bypass capacitor for the SN74LVC257ANSR V_CC pin?

Texas Instruments specifies a 0.1μF ceramic capacitor placed as close as possible to the V_CC pin (Pin 16) of the SN74LVC257ANSR. This capacitor must be low-ESR, X7R or better dielectric, and mounted directly adjacent to the pin with minimal trace length to suppress high-frequency noise and maintain stable supply during fast output transitions.

How does the OE pin behave in the SN74LVC257ANSR?

The OE pin on the SN74LVC257ANSR is active-low: when OE = HIGH, all four Y outputs enter high-impedance state regardless of A/B or data inputs; when OE = LOW, multiplexing proceeds normally. To ensure safe power-up behavior, TI recommends tying OE to V_CC via a pullup resistor (value determined by driver sink capability) to prevent bus contention during initialization.

Is the SN74LVC257ANSR pin-compatible with other LVC-series multiplexers?

Yes, the SN74LVC257ANSR is functionally and pin-compatible with SN74LVC157ADR (SOIC-16) and SN74LVC257APWR (TSSOP-16) - all share identical pin assignments for 1A–4B, 1Y–4Y, A/B, OE, V_CC, and GND. However, mechanical compatibility depends on package-specific land patterns; SOP-16 (NS) cannot be substituted for SOIC-16 (D) or TSSOP-16 (PW) without PCB revision.