Texas Instruments SN74AHC157PWG4

Overview

SN74AHC157PWG4 from Texas Instruments is a quadruple 2-line to 1-line data selector/multiplexer in a 16-pin TSSOP package, operating from 2 V to 5.5 V with true output logic, 7.5 ns max propagation delay at 5 V (CL = 15 pF), and ±8 mA output drive capability. It routes four independent 2-input data channels under common strobe control and is used in digital bus selection, signal routing, and address/data path switching in industrial control and embedded logic systems.

For engineers reviewing the SN74AHC157PWG4 datasheet, SN74AHC157PWG4 pinout, SN74AHC157PWG4 application, or SN74AHC157PWG4 equivalent, key selection considerations include its 16-pin TSSOP (PW) footprint, active-low strobe (G) enabling synchronized channel gating, true (non-inverted) output behavior, rail-to-rail input compatibility, and guaranteed operation across –40°C to +125°C ambient temperature.

Technical Context

The SN74AHC157PWG4 implements four independent 2:1 multiplexers sharing a single active-low strobe (G) input: when G is high, all Y outputs are forced low; when G is low, the A/B select line determines whether inputs 1A–4A or 1B–4B are routed to outputs 1Y–4Y. Each channel operates with true (non-inverting) logic - no internal inversion occurs between selected input and output.

It uses advanced CMOS AHC technology for low power consumption (ICC ≤ 40 µA at 5.5 V), high noise immunity (HBM ±2000 V), and fast switching (tPLH/tPHL ≤ 7.5 ns at VCC = 5 V, CL = 15 pF). Input thresholds scale with VCC, supporting mixed-voltage interfacing across 2 V–5.5 V supply rails without level shifters.

Key Specifications

Pinout & Package

TSSOP-16 (PW) package: 5.00 mm × 6.4 mm body size, 0.65 mm lead pitch, surface-mount, RoHS-compliant, moisture sensitivity level 1 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC157APWR and 74HC157D,653, the SN74AHC157PWG4 uniquely balances wide 2 V–5.5 V operation, industrial temperature range, and 7.5 ns speed in a compact TSSOP-16 package-making it optimal for mixed-voltage industrial controllers requiring long-term supply stability and board-level ESD resilience.

Availability

SN74AHC157PWG4 is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, digital test equipment signal routing, embedded system address/data bus multiplexing, and legacy interface protocol translation requiring stable component supply across extended temperature ranges and mixed-voltage environments.

Supply support for SN74AHC157PWG4 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 over 90 years of innovation in industrial, automotive, and communications markets.

The SN74AHC157PWG4 belongs to TI's AHC logic family, designed for high-speed, low-power, mixed-voltage digital interfacing in industrial automation, test equipment, and embedded control systems where reliability and broad supply compatibility are critical.

FAQ

What is the maximum operating frequency supported by SN74AHC157PWG4?

The SN74AHC157PWG4 does not specify a maximum clock frequency directly, but its typical propagation delay is 4.1 ns and maximum is 7.5 ns at VCC = 5 V with CL = 15 pF. This supports reliable data routing in digital systems with signal periods ≥15 ns - effectively enabling use in circuits operating up to approximately 65 MHz toggle rate. Actual usable frequency depends on load capacitance, trace routing, and system timing margins.

Does SN74AHC157PWG4 support 3.3 V-only operation?

Yes, SN74AHC157PWG4 fully supports 3.3 V operation: its recommended VCC range is 2 V to 5.5 V, and all electrical characteristics-including propagation delay (≤11.5 ns), output drive (±4 mA), and input thresholds-are specified at VCC = 3.3 V ± 0.3 V. It interfaces seamlessly with 3.3 V microcontrollers and FPGAs without level shifters.

Can unused inputs on SN74AHC157PWG4 be left floating?

No, unused inputs on SN74AHC157PWG4 must not be left floating. Per TI's design guidance, all unused inputs-including A/B, individual data inputs (e.g., 1A, 1B), and G-must be tied to VCC or GND to prevent undefined logic states, increased power consumption, and potential oscillation. For example, tie unused 1A to GND and 1B to VCC if only one source is used per channel.

Is SN74AHC157PWG4 pin-compatible with SN74HC157N?

Yes, SN74AHC157PWG4 is functionally and pin-compatible with SN74HC157N in terms of logic function, pin numbering, and signal roles (A/B, G, 1A–4B, 1Y–4Y, VCC, GND). However, they differ in package (TSSOP-16 vs PDIP-16), speed (7.5 ns vs 19 ns max tPD), and supply range (2–5.5 V vs 2–6 V). No PCB redesign is needed for footprint replacement if adapter or rework is acceptable.

What thermal considerations apply to SN74AHC157PWG4 in continuous operation?

SN74AHC157PWG4 has a junction-to-ambient thermal resistance (RθJA) of 135.9°C/W in its TSSOP-16 (PW) package. At maximum ICC of 40 µA and worst-case output loading, self-heating is negligible. However, in high-output-drive scenarios (e.g., driving 8 mA continuously), PCB copper area and airflow become relevant. TI recommends a minimum 100 mm² exposed pad or thermal relief pattern beneath the package for sustained industrial operation at +125°C ambient.