Texas Instruments SN74AHC158PWR

Overview

SN74AHC158PWR from Texas Instruments is a quadruple 2-line to 1-line data selector/multiplexer in TSSOP-16 package, operating from 2 V to 5.5 V, delivering inverted output logic, common strobe (G) control, and propagation delays as low as 4.1 ns at 5 V with 15-pF load. It serves in digital signal routing for microcontroller peripheral selection, address decoding, and bus multiplexing in industrial control modules.

For engineers reviewing the SN74AHC158PWR datasheet, SN74AHC158PWR pinout, SN74AHC158PWR application, or SN74AHC158PWR equivalent, key selection criteria include its 16-pin TSSOP footprint, guaranteed 25-mA output drive capability, latch-up immunity exceeding 250 mA per JESD 17, ESD robustness (2000-V HBM), and compatibility with mixed-voltage 3.3-V/5-V system interfaces.

Technical Context

The SN74AHC158PWR implements four independent 2:1 multiplexers sharing a single active-low strobe (G) input and a common select line (A/B). When G is high, all outputs (1Y–4Y) are forced high regardless of inputs; when G is low, each Y output reflects the inverted value of the selected A or B input based on A/B state.

Its CMOS AHC-family architecture ensures rail-to-rail output swing, low static current (ICC ≤ 40 µA at 5.5 V), and input thresholds scaled to VCC (VIH = 0.7×VCC, VIL = 0.3×VCC). Switching performance is characterized across 15-pF and 50-pF loads, with tPLH/tPHL ranging from 4.1 ns to 19.5 ns depending on VCC and load capacitance.

Key Specifications

Pinout & Package

TSSOP-16 package (PW), 4.4 mm × 5.0 mm body, 0.65 mm pitch, 1.2 mm max height, 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 SN74LV158APWR, SN74AHC158PWR delivers faster switching and stronger drive for 5-V systems; compared with 74AHC157PW, it provides inverted outputs essential for active-low enable schemes but requires logic inversion in upstream/downstream stages if true outputs are needed.

Availability

SN74AHC158PWR is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, microcontroller peripheral selection, legacy bus interface translation, and digital test equipment signal routing requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74AHC158PWR 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 90 years of innovation in industrial, automotive, and communications markets.

The SN74AHC158PWR belongs to TI's advanced high-speed CMOS (AHC) logic family, designed specifically for low-power, high-noise-immunity digital signal routing in space-constrained industrial and automation equipment.

FAQ

What is the maximum clock frequency supported by SN74AHC158PWR in a multiplexing application?

The SN74AHC158PWR does not operate on a clock; it is a combinational logic device. Its usable toggle rate depends on propagation delay and system timing margins. With tPHL/tPLH as low as 4.1 ns at 5 V and 15-pF load, SN74AHC158PWR supports reliable data switching up to approximately 100 MHz in well-designed PCB layouts with controlled trace impedance and proper decoupling. Always verify setup/hold times against your controller's timing specifications when using SN74AHC158PWR in high-speed routing.

Does SN74AHC158PWR require external pull-up or pull-down resistors on unused inputs?

Yes. Per TI's SCBA004 application report, all unused inputs of SN74AHC158PWR - including A/B, G, and any unconnected A or B lines - must be tied to VCC or GND to prevent floating nodes that cause increased ICC, oscillation, or premature device failure. Leaving inputs unconnected violates recommended operating conditions and voids parametric guarantees. This requirement applies strictly to SN74AHC158PWR and is documented in its official datasheet Section "Recommended Operating Conditions" Note 3.

Can SN74AHC158PWR be used in mixed-voltage systems with both 3.3-V and 5-V logic?

Yes. SN74AHC158PWR operates from 2 V to 5.5 V and features voltage-tolerant inputs: VI can range from –0.5 V to 7 V, allowing safe interfacing with 5-V outputs even when VCC = 3.3 V. Outputs swing rail-to-rail, so SN74AHC158PWR driven at 3.3 V produces 0–3.3-V signals compatible with 3.3-V receivers, while at 5 V it delivers 0–5-V levels for legacy 5-V loads. This dual-voltage flexibility is a core design feature of the SN74AHC158PWR.

Is SN74AHC158PWR pin-compatible with SN74AHC157PWR?

No. Although SN74AHC158PWR and SN74AHC157PWR share identical pinouts and package (TSSOP-16), they differ functionally: SN74AHC158PWR provides inverted outputs (Y = NOT(selected input)), while SN74AHC157PWR provides true outputs (Y = selected input). Swapping them without logic inversion elsewhere will cause functional failure. The SN74AHC158PWR datasheet explicitly states this inversion behavior, making it incompatible as a drop-in replacement for SN74AHC157PWR in existing designs.

What thermal derating guidance applies to SN74AHC158PWR in high-density PCB layouts?

SN74AHC158PWR in TSSOP-16 (PW) has a θJA of 108°C/W. At 5 V and 25°C ambient, worst-case power dissipation is ~1.1 mW (ICC × VCC), generating negligible self-heating. However, in high-density layouts with adjacent heat sources, maintain ≥0.5-mm clearance from thermal vias or copper pours, avoid enclosing the device under shield cans without ventilation, and use at least two 0.3-mm thermal vias per power/ground pad. These practices ensure SN74AHC158PWR remains within its –40°C to +85°C operating range under sustained load.