Texas Instruments SN74LVC2G157DCT3

Overview

SN74LVC2G157DCT3 from Texas Instruments is a single 2-line to 1-line data selector multiplexer in an 8-pin SSOP package, supporting 1.65 V to 5.5 V supply operation, delivering true and complementary outputs (Y and Y), with 6 ns max propagation delay at 3.3 V and ±24 mA output drive-used for signal routing in embedded PC and sensor interface applications.

For engineers reviewing the SN74LVC2G157DCT3 datasheet, SN74LVC2G157DCT3 pinout, SN74LVC2G157DCT3 application, or SN74LVC2G157DCT3 equivalent, key selection considerations include Ioff-enabled partial-power-down support, 5.5 V tolerant inputs for level translation, low ICC (10 µA max), and NanoFree™-compatible SSOP packaging for space-constrained designs.

Technical Context

This device implements a positive-logic 2:1 multiplexer with a common strobe (G) input controlling output enable: when G = HIGH, both outputs are forced to fixed states (Y = LOW, Y = HIGH); when G = LOW, the A/B select line routes either A or B to Y (true) and Y (complementary). It uses standard CMOS inputs and balanced high-drive push-pull outputs.

Designed for mixed-voltage systems, it supports down-translation-inputs accept up to 5.5 V regardless of VCC (1.65–5.5 V), enabling interfacing between 5-V sensors and 3.3-V or 1.8-V controllers. Ioff circuitry actively disables outputs during power-down to prevent back-drive current and support live insertion.

Key Specifications

Pinout & Package

SN74LVC2G157DCT3 is housed in an 8-pin SSOP (DCT) package measuring 2.95 mm × 2.80 mm, optimized for automated assembly and thermal performance (RθJA = 192 °C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC2G157DCT3, SN74LVC1G157DCKR saves board area but sacrifices functional completeness, while 74AUP1G157GW,125 offers faster speed at lower voltage but eliminates critical 5-V compatibility and Ioff protection-making SN74LVC2G157DCT3 the only option meeting full industrial interface requirements.

Availability

SN74LVC2G157DCT3 is available at Aetrix Electronics and suitable for embedded PC, HVAC field transmitters, and wireless data access cards requiring stable component supply, long-term manufacturability, and industrial-grade ESD robustness.

Supply support for SN74LVC2G157DCT3 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 50 years of innovation in high-reliability interface and signal-path components.

The SN74LVC2G157 belongs to TI's LVC logic family-designed for low-voltage, high-speed, mixed-signal interfacing in space- and power-constrained industrial and computing applications.

FAQ

What is the function of the G (strobe) pin on the SN74LVC2G157DCT3?

The G pin is the global strobe enable input for the SN74LVC2G157DCT3. When G is HIGH, the outputs are forced to fixed states: Y = LOW and Y = HIGH, regardless of A, B, or A/B states. When G is LOW, the device operates as a normal 2:1 multiplexer, routing either A or B to Y and Y based on the A/B select line. This enables synchronous enable/disable of data routing in timing-critical systems.

Does the SN74LVC2G157DCT3 support level translation between 5-V and 3.3-V systems?

Yes, the SN74LVC2G157DCT3 supports bidirectional level translation. Its inputs tolerate up to 5.5 V independent of VCC, allowing 5-V sensor outputs to drive the A, B, or A/B pins even when VCC = 3.3 V or 1.8 V. The outputs swing rail-to-rail (0 V to VCC), so Y and Y reflect the selected input level translated down to the VCC domain-enabling seamless interfacing without external translators.

Can the SN74LVC2G157DCT3 be used in partial-power-down applications?

Yes, the SN74LVC2G157DCT3 includes Ioff circuitry specifically designed for partial-power-down operation. When VCC = 0 V but inputs remain at valid logic levels (e.g., 5 V), Ioff limits input/output leakage to ±10 µA max, preventing damaging back-current flow through the device. This feature supports live insertion, hot-swap capability, and safe operation in multi-rail systems where subsystems power up/down independently.

What is the maximum capacitive load the SN74LVC2G157DCT3 can drive while maintaining specified timing?

The SN74LVC2G157DCT3 is characterized for loads up to 50 pF while meeting all switching specifications (e.g., 6 ns tpd at 3.3 V). The datasheet permits operation with up to 70 pF for non-critical timing paths, though propagation delay increases nonlinearly beyond 50 pF. For reliable 100-MHz control bus operation, keep total load (trace + receiver input + probe) ≤50 pF and use proper termination and decoupling.

How does the SN74LVC2G157DCT3 differ from the SN74LVC1G157 in terms of functionality?

The SN74LVC2G157DCT3 provides both true (Y) and complementary (Y) outputs in an 8-pin SSOP package, whereas the SN74LVC1G157 is a 5-pin SC70 device offering only the true output (Y). The SN74LVC2G157DCT3 also includes a dedicated strobe (G) input for global enable/disable, while the SN74LVC1G157 uses an active-low enable (OE) and lacks Y. These differences make SN74LVC2G157DCT3 suitable for differential routing and synchronous control not possible with the single-output variant.