Texas Instruments SN74AHCT158PW

Overview

SN74AHCT158PW from Texas Instruments is a quadruple 2-line to 1-line data selector/multiplexer IC operating at 4.5 V to 5.5 V, featuring TTL-compatible inputs, an active-low common strobe (G), inverted outputs, and 16-pin TSSOP packaging. It routes one of two 4-bit input sources to four outputs based on the A/B select line, used in digital logic routing, address decoding, and bus multiplexing applications.

For engineers reviewing the SN74AHCT158PW datasheet, SN74AHCT158PW pinout, SN74AHCT158PW application, or SN74AHCT158PW equivalent, key selection criteria include its 5-V CMOS logic family compatibility, guaranteed 8-mA output drive, 7.5-ns typical propagation delay (CL = 15 pF), and TSSOP-16 thermal performance (θ_JA = 108°C/W).

Technical Context

The SN74AHCT158PW implements four independent 2:1 multiplexers with shared strobe control and inverted outputs. Each channel selects between A or B inputs using the A/B select line, with output enable governed by G - high disables all outputs (drives high), low enables selection and inversion.

It uses advanced high-speed CMOS (AHCT) technology for TTL-level input compatibility while maintaining CMOS power efficiency. Logic thresholds are VIH = 2 V (min), VIL = 0.8 V (max), ensuring robust noise immunity in mixed-voltage systems.

Key Specifications

Pinout & Package

TSSOP-16 package (PW), 4.4 mm × 5.0 mm body, 0.65 mm lead pitch, 1.2 mm max height, exposed pad not present, RoHS-compliant NiPdAu finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 4-channel 2:1 multiplexer applications.

Compared with SN74AHCT158PW, SN74AHCT157PW offers identical form-factor and 5-V operation but delivers non-inverted outputs - eliminating external inverters at the cost of logic polarity change; 74LVC157PW enables 3.3-V integration and faster switching but requires full voltage domain isolation from 5-V subsystems.

Availability

SN74AHCT158PW is available at Aetrix Electronics and suitable for industrial control systems, legacy 5-V embedded instrumentation, and digital test equipment requiring stable component supply and long-term obsolescence management.

Supply support for SN74AHCT158PW 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 U.S.-based semiconductor company specializing in analog, embedded processing, and logic solutions with over 90 years of innovation in industrial, automotive, and communications markets.

The SN74AHCT158PW belongs to TI's AHCT logic family - designed specifically for 5-V systems requiring TTL input compatibility, low power consumption, and robust ESD/latch-up performance in commercial and industrial temperature ranges.

FAQ

What is the maximum recommended operating voltage for the SN74AHCT158PW?

The SN74AHCT158PW has a recommended VCC range of 4.5 V to 5.5 V. Absolute maximum supply voltage is 7 V, but sustained operation above 5.5 V risks parametric degradation and reduced reliability. Always maintain VCC within the recommended range for guaranteed timing, drive strength, and logic threshold compliance per the SCLS348J datasheet.

Does the SN74AHCT158PW support 3.3-V input logic levels?

No - the SN74AHCT158PW is designed for 5-V operation and requires TTL-compatible input thresholds: VIH ≥ 2 V and VIL ≤ 0.8 V. A 3.3-V CMOS high-level signal (typically ~3.3 V) meets VIH but may not guarantee noise margin across temperature; 3.3-V logic families like LVC should be used instead for native 3.3-V systems. The SN74AHCT158PW itself does not accept or translate 3.3-V inputs reliably.

Is the SN74AHCT158PW pin-compatible with the SN74AHCT157PW?

Yes - the SN74AHCT158PW and SN74AHCT157PW share identical TSSOP-16 pinouts, supply requirements, and timing specifications. The sole functional difference is output polarity: SN74AHCT158PW provides inverted outputs (Y = NOT(selected)), while SN74AHCT157PW provides true outputs (Y = selected). No PCB changes are required for substitution if logic polarity is accounted for in firmware or downstream logic.

What is the thermal resistance (θJA) of the SN74AHCT158PW package?

The SN74AHCT158PW in TSSOP-16 (PW) package has a specified junction-to-ambient thermal resistance (θJA) of 108°C/W under standard JEDEC test conditions. This value assumes a 1-inch² copper pad with two vias; actual board-level θJA will vary based on PCB layout, copper area, and airflow. For continuous operation near maximum ratings, thermal derating per the absolute maximum ratings table is advised.

How does the strobe (G) input affect output behavior on the SN74AHCT158PW?

When G is high, all four Y outputs are forced high regardless of A/B state or input data - this is a hard-wired disable condition. When G is low, the device performs normal 2:1 selection: A/B = low routes A inputs to Y outputs (inverted), A/B = high routes B inputs to Y outputs (inverted). G thus provides synchronous, glitch-free bus isolation without requiring hold-time coordination on A/B.