Texas Instruments SN74AHC158D

Overview

SN74AHC158D from Texas Instruments is a quadruple 2-line to 1-line data selector/multiplexer IC operating across 2-V to 5.5-V V_CC, delivering inverted output logic, common strobe (G) control, and ±8-mA output drive at 5 V. It routes four independent 2-input data paths under select-bit (A/B) and enable control, used in digital bus routing, address decoding, and signal path selection in industrial control logic.

For engineers reviewing the SN74AHC158D datasheet, SN74AHC158D pinout, SN74AHC158D application, or SN74AHC158D equivalent, key selection criteria include its 16-pin SOIC-D package, guaranteed 7.5-ns propagation delay (V_CC = 5 V, C_L = 15 pF), latch-up immunity >250 mA per JESD 17, and compatibility with 3.3-V and 5-V mixed-signal systems.

Technical Context

The SN74AHC158D implements four independent 2:1 multiplexers sharing one active-low strobe (G) input and one 2-bit select bus (A/B). Each channel selects between inputs A and B based on A/B state, then inverts and drives the corresponding Y output. Strobe override forces all outputs high regardless of select or data states.

Its AHC logic family ensures CMOS-level power efficiency with TTL-compatible thresholds, rail-to-rail output swing, and robust ESD protection (2000-V HBM, 200-V MM, 1000-V CDM). Input transition rate limits (20 ns/V at 5 V) ensure reliable timing margin in synchronous digital systems.

Key Specifications

Pinout & Package

SN74AHC158D uses a 16-pin SOIC (D) package, 7.5-mm wide, 1.75-mm height, with standard 1.27-mm pitch. Pin 1 is located at the top-left corner with index marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LV158AD, SN74AHC158D offers tighter timing and higher drive for 5-V industrial use; versus 74AHC157D, it provides inverted outputs for direct compatibility with active-low enable schemes - both alternatives require functional validation but share identical SOIC-D footprint.

Availability

SN74AHC158D is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, embedded microcontroller bus multiplexing, and test equipment signal path selection requiring stable component supply and long-term production continuity.

Supply support for SN74AHC158D 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 ICs, with decades of experience in high-reliability industrial and automotive-grade components.

The SN74AHC158D belongs to TI's AHC advanced high-speed CMOS logic family, designed specifically for low-power, high-noise-immunity digital interfacing in industrial automation, test instrumentation, and communications infrastructure.

FAQ

What is the maximum clock frequency supported by SN74AHC158D in multiplexer mode?

SN74AHC158D does not operate as a clocked device but as a combinatorial multiplexer. Its 7.5-ns maximum propagation delay at 5 V allows reliable operation with input data rates up to ~100 MHz in static selection configurations. For dynamic A/B or G toggling, setup/hold times (1 ns min) and transition rate limits (20 ns/V) must be observed to avoid metastability.

Does SN74AHC158D support partial power-down or I²C bus isolation?

No - SN74AHC158D lacks bus-hold, power-down, or high-impedance isolation features. When G is high, outputs are actively driven high; they do not enter high-Z state. It cannot isolate I²C buses. For bidirectional isolation, dedicated I²C switches like TCA9548A are required. SN74AHC158D is strictly unidirectional and non-isolating.

Can SN74AHC158D be used with 3.3-V microcontrollers driving 5-V peripherals?

Yes - SN74AHC158D accepts 3.3-V logic levels as valid inputs (V_IL = 0.9 V, V_IH = 2.1 V @ V_CC = 3.3 V) and can drive 5-V TTL loads with ±8-mA output current. However, outputs swing rail-to-rail (0–5 V), so ensure downstream 3.3-V receivers tolerate 5-V inputs or use series resistors/clamp diodes.

Is SN74AHC158D pin-compatible with SN74AHC157D?

Yes - SN74AHC158D and SN74AHC157D share identical 16-pin SOIC-D pinout, supply, and timing specifications. The sole functional difference is output polarity: SN74AHC158D provides inverted outputs, while SN74AHC157D provides true outputs. No PCB changes are needed for substitution if system logic accommodates inversion.

What thermal considerations apply to SN74AHC158D in continuous operation?

SN74AHC158D has θ_JA = 73°C/W in SOIC-D package. At 5 V and full 8-mA load on all four outputs, worst-case power dissipation is ~22 mW. With 25°C ambient, junction temperature rise is ~1.6°C - well within safe limits. No heatsinking is required, but ensure ≥250-mil clearance from adjacent heat sources per TI layout guidelines.