Texas Instruments SN74AHCT158DE4

Overview

SN74AHCT158DE4 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, inverted outputs, and a common strobe (G) input for output enable/disable control. It routes one of two 4-bit data sources to four outputs based on the A/B select line, with propagation delays as low as 1 ns (typical) at 15 pF load and 5 V supply - used in digital logic routing, address/data path selection, and bus multiplexing in industrial control systems.

For engineers reviewing the SN74AHCT158DE4 datasheet, SN74AHCT158DE4 pinout, SN74AHCT158DE4 application, or SN74AHCT158DE4 equivalent, this page delivers verified functional identity, SOIC-16 package mapping, confirmed 4.5–5.5 V operation, true inverted multiplexing behavior, and validated alternatives aligned with TI's official ordering matrix and SCLS348J revision J specification.

Technical Context

The SN74AHCT158DE4 implements four independent 2:1 multiplexers sharing a single active-low strobe (G) and a common select line (A/B), enabling simultaneous selection across all channels. Each channel accepts TTL-level inputs (VIH = 2 V min, VIL = 0.8 V max) and delivers CMOS-compatible inverted outputs with ±8 mA drive capability.

Its logic function follows a strict truth table: when G = H, all Y outputs are high regardless of A/B or data inputs; when G = L, each Yn = NOT(An if A/B = L else Bn). No internal latching or memory is present - it is purely combinational with no clock or state retention.

Key Specifications

Pinout & Package

SN74AHCT158DE4 is supplied in a 16-pin SOIC (D) package with 1.27 mm pitch, 10.2 mm × 6.2 mm body size, and 1.75 mm maximum height - compliant with JEDEC MS-012 and RoHS.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AHCT158DE4, SN74AHCT157N offers identical form-factor and electrical behavior except output inversion, making it a direct functional substitute where polarity is flexible; 74LVC157APW provides superior speed and voltage scalability but requires layout revision and voltage domain isolation.

Availability

SN74AHCT158DE4 is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, digital test equipment signal routing, legacy microprocessor address decoding, and embedded system bus arbitration requiring stable component supply, long-term lifecycle support, and RoHS-compliant SOIC packaging.

Supply support for SN74AHCT158DE4 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 founded in 1930, specializing in analog, embedded processing, and logic ICs with global manufacturing and quality certification to ISO 9001 and IATF 16949.

The SN74AHCT158DE4 belongs to TI's 74AHCT logic family - designed specifically for 5 V TTL-to-CMOS interfacing with guaranteed AC/DC specifications across commercial temperature ranges.

FAQ

What is the logic function of SN74AHCT158DE4?

The SN74AHCT158DE4 implements four independent 2:1 data selectors with inverted outputs. When the strobe (G) is low, it routes either the A-input or B-input (selected by the A/B line) to each corresponding Y-output, then inverts the selected bit. When G is high, all Y outputs are forced high regardless of other inputs - no latching or memory is involved.

Does SN74AHCT158DE4 support 3.3 V operation?

No. SN74AHCT158DE4 is specified only for 4.5 V to 5.5 V VCC operation per its recommended operating conditions. Applying 3.3 V may result in undefined logic states, marginal noise margins, or failure to meet timing specifications - use 74LVC157 or 74LVCH157 for 3.3 V systems.

Is SN74AHCT158DE4 pin-compatible with SN74AHCT157N?

Yes. SN74AHCT158DE4 and SN74AHCT157N share identical SOIC-16 pinouts, supply requirements, and timing characteristics - the sole functional difference is that SN74AHCT158DE4 provides inverted outputs while SN74AHCT157N provides non-inverted outputs.

What does "TTL-voltage compatible" mean for SN74AHCT158DE4 inputs?

It means SN74AHCT158DE4 accepts standard TTL logic thresholds: VIH ≥ 2.0 V guarantees recognition as HIGH, and VIL ≤ 0.8 V guarantees recognition as LOW - allowing direct connection to legacy 5 V TTL outputs without pull-up resistors or level shifters.

Can unused inputs on SN74AHCT158DE4 be left floating?

No. Per TI's SCBA004 application report, all unused inputs of SN74AHCT158DE4 must be tied to VCC or GND to prevent increased ICC, oscillation, or ESD susceptibility. Floating inputs cause unpredictable current draw and potential device malfunction in commercial temperature operation.