Texas Instruments SN74HC158N

Overview

SN74HC158N from Texas Instruments is a high-speed CMOS 2-line-to-4-line data selector/multiplexer with active-low enable and inverted outputs. It operates across 2 V to 6 V, delivers 11 ns typical propagation delay at 6 V, supports ±6-mA output drive, and drives up to 15 LSTTL loads in industrial temperature range (−40°C to 85°C). It routes one of two 4-bit data sources to four inverted outputs under select and strobe control.

For engineers reviewing the SN74HC158N datasheet, SN74HC158N pinout, SN74HC158N application, or SN74HC158N equivalent, key selection criteria include its dual-source 4-bit multiplexing capability, guaranteed inverted output logic, wide supply voltage tolerance, low ICC (80 µA max), and PDIP-16 package compatibility with legacy through-hole prototyping and industrial control PCBs.

Technical Context

The SN74HC158N implements four independent 2:1 multiplexer gates, each selecting between corresponding A and B inputs based on the common A/B select line. All outputs are inverted, and a single active-low strobe (G) enables or disables all outputs simultaneously.

Its architecture uses standard HC-series CMOS logic with Schmitt-trigger input thresholds only on G (per TI application note SCBA004 guidance), while A/B, A_n, and B_n inputs follow standard TTL-compatible VIH/VIL thresholds. Output drive strength is symmetric (±6 mA at 5 V), supporting direct interfacing with LSTTL and other 5-V logic families without level-shifting.

Key Specifications

Pinout & Package

SN74HC158N is housed in a 16-pin plastic dual in-line package (PDIP-N), 0.600-inch body width, with 0.100-inch lead pitch and through-hole mounting. Pin 1 is located at the top-left corner adjacent to the notch or dot marking.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 2-to-4-line data selector applications.

Compared with SN74HC158N, SN74HCT158N improves robustness against marginal input voltages without layout changes, while SN74AC158N trades higher power for measurable speed gain - neither offers pin-compatible replacement without validating board-level timing and thermal constraints.

Availability

SN74HC158N is available at Aetrix Electronics and suitable for industrial PLC I/O modules, legacy bus address decoding, dual-source display interfaces, and automated test equipment requiring stable component supply across extended product lifecycles.

Supply support for SN74HC158N 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 industrial-grade component development.

The SN74HC158N belongs to TI's 74HC high-speed CMOS logic family, designed specifically for low-power, wide-voltage-range digital interfacing in industrial, automotive, and communications systems where reliability and interoperability are critical.

FAQ

What logic family does SN74HC158N belong to, and how does it differ from 74LS or 74F variants?

SN74HC158N belongs to the 74HC (High-Speed CMOS) logic family. Unlike bipolar 74LS or 74F, it uses CMOS transistors, delivering lower power consumption (80 µA max ICC vs. several mA for LS), wider supply range (2–6 V vs. fixed 5 V), and higher noise immunity. Its output structure is push-pull (not open-collector), and it features symmetrical ±6-mA drive at 5 V - making it ideal for modern mixed-voltage designs where SN74HC158N replaces obsolete TTL parts without redesign.

Does SN74HC158N support high-impedance (tri-state) outputs when disabled?

No, SN74HC158N does not provide tri-state outputs. When the strobe input G is high, all Y outputs are forced to logic high (VCC), not high-impedance. This is a functional characteristic of the 'HC158 series - outputs are always driven, either by selected inverted data or by internal pull-up action. If bus-sharing or wired-OR functionality is required, SN74HC158N cannot be used; consider SN74HC257 (quad 2:1 mux with true tri-state) instead.

Can SN74HC158N operate reliably at 3.3 V, and what are the guaranteed timing parameters at that voltage?

Yes, SN74HC158N is fully specified down to 2 V, so 3.3 V operation is well within its recommended range. At VCC = 3.3 V and TA = 25°C, typical propagation delay is 15 ns (max 32 ns at CL = 50 pF), and output drive is ±4.2 mA. Input thresholds scale proportionally (VIH ≈ 2.0 V, VIL ≈ 1.0 V), ensuring clean logic recognition from 3.3 V microcontrollers - a key advantage confirmed in SN74HC158N's recommended operating conditions table.

What is the maximum capacitive load SN74HC158N can drive while maintaining specified timing?

SN74HC158N is characterized for CL = 50 pF and CL = 150 pF loads. At CL = 150 pF and VCC = 6 V, typical tpd increases to 18 ns (vs. 11 ns at 50 pF), remaining within datasheet limits. Driving loads beyond 150 pF risks violating max tpd (49 ns) and may cause output transition degradation. For >150 pF routing (e.g., long traces or multiple inputs), add local buffering - SN74HC158N itself does not include slew-rate control or transmission-line drive enhancement.

Is SN74HC158N RoHS compliant, and what is its moisture sensitivity level (MSL)?

Yes, SN74HC158N is RoHS compliant (lead-free NiPdAu finish). As a PDIP package, it has no MSL rating - the "N/A for Pkg Type" designation applies because through-hole packages are not moisture-sensitive like surface-mount devices. No bake-out or special handling is required prior to soldering; standard wave or hand-soldering profiles apply per JEDEC J-STD-001.