Texas Instruments SN74LVC257ADR

Overview

SN74LVC257ADR 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 supports mixed-voltage interfacing (inputs tolerate up to 5.5V), delivers 4.6ns max propagation delay at 3.3V, and enables bus-organized signal routing in 4-bit data paths - used in telecom infrastructure, I/O expanders, and test equipment.

For engineers reviewing the SN74LVC257ADR datasheet, SN74LVC257ADR pinout, SN74LVC257ADR application, or SN74LVC257ADR equivalent, key selection criteria include its 3-state output control via active-low OE, voltage translation capability between 3.3V and 5V logic domains, and SOIC-16 package compatibility with legacy board layouts.

Technical Context

The SN74LVC257ADR implements four independent 2:1 multiplexers sharing a common select (A/B) and output-enable (OE) control. Each channel routes either input A or B to its Y output based on the logic level of A/B, while OE asserts high-impedance state across all four outputs simultaneously.

Its CMOS design ensures balanced drive strength (±24mA at 3V), low dynamic power (15.5pF typical C_pd), and robust ESD protection (±2000V HBM). Input overvoltage tolerance and rail-to-rail output swing support interoperability in heterogeneous voltage systems without external level shifters.

Key Specifications

Pinout & Package

SN74LVC257ADR uses the 16-pin SOIC (D) package with 9.90 mm × 6.00 mm body size and standard 1.27 mm pitch. Pin assignments are identical across D, DB, NS, PW, and RGY packages per TI's pin configuration diagrams.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC157ADR and 74LVC257PW, SN74LVC257ADR uniquely combines 3-state control, SOIC-16 mechanical compatibility, and industrial temperature range - making it optimal for bus-oriented industrial and telecom systems requiring proven manufacturability and long-term availability.

Availability

SN74LVC257ADR is available at Aetrix Electronics and suitable for telecom infrastructure, network switches, and industrial I/O expanders requiring stable component supply across extended product lifecycles.

Supply support for SN74LVC257ADR 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 components.

The SN74LVC257ADR belongs to TI's LVC logic family - engineered for low-voltage, high-speed operation in mixed-signal systems where voltage translation, noise immunity, and bus integrity are critical.

FAQ

What is the maximum input voltage rating for SN74LVC257ADR?

The SN74LVC257ADR accepts input voltages up to 5.5V regardless of V_CC level, enabling direct interfacing with 5V logic sources without external level-shifting circuitry. This overvoltage tolerance is specified in Section 5.1 Absolute Maximum Ratings and confirmed in the Recommended Operating Conditions table, where VI is rated 0–5.5V across the full V_CC range (1.65V–3.6V). The feature is implemented using robust input protection structures that prevent damage or functional disruption.

Does SN74LVC257ADR support 3.3V-only systems?

Yes, SN74LVC257ADR operates fully within 3.3V systems: its V_CC range includes 3.3V ±0.3V, and all DC and switching specifications (e.g., t_pd = 4.6ns, I_OH/I_OL = ±24mA) are guaranteed at that voltage. The device also meets 3.3V LVTTL/LVCMOS logic thresholds (VIH ≥ 2.0V, VIL ≤ 0.8V), ensuring compatibility with standard 3.3V microcontrollers and FPGAs without level conversion.

How does the OE pin function on SN74LVC257ADR?

The OE (Output Enable) pin on SN74LVC257ADR is an active-low control that places all four Y outputs into high-impedance state when driven high. When OE is low, outputs reflect the selected A/B input per channel. This behavior is defined in Table 7-1 Function Table and verified in Figure 4-1 pin diagram. Proper pull-up biasing of OE is recommended during power-up to avoid unintended output activation before system initialization completes.

What package type is used by SN74LVC257ADR?

SN74LVC257ADR uses the 16-pin SOIC (D) package with dimensions 9.90 mm × 6.00 mm and 1.27 mm lead pitch. This industry-standard package is documented in TI's PACKAGE OPTION ADDENDUM and Mechanical, Packaging, and Orderable Information section. It supports wave soldering and reflow processes per Level-1 MSL rating and features NIPDAU lead finish for RoHS compliance.

Can SN74LVC257ADR be used as a level translator?

Yes, SN74LVC257ADR functions as a bidirectional level translator: inputs accept 0–5.5V signals while outputs swing rail-to-rail between GND and V_CC (1.65V–3.6V). This allows it to translate 5V logic high levels down to 3.3V-compatible outputs, and conversely, drive 5V-tolerant inputs from a 3.3V source. The capability is explicitly cited in Section 7.3 Feature Description and validated in Figure 8-1 Typical Application schematic.