Texas Instruments SN74AHC157RGYR

Overview

SN74AHC157RGYR from Texas Instruments is a quadruple 2-line to 1-line data selector/multiplexer in a 16-pin VQFN package (4 mm × 3.5 mm), operating from 2 V to 5.5 V supply, with true output logic, active-low strobe (G), and 4-bit parallel data routing capability. It delivers propagation delays as low as 4.1 ns at 5 V (CL = 15 pF) and supports industrial temperature range (–40°C to +125°C), making it suitable for digital bus selection in microcontroller peripheral interfaces.

For engineers reviewing the SN74AHC157RGYR datasheet, SN74AHC157RGYR pinout, SN74AHC157RGYR application, or SN74AHC157RGYR equivalent, key selection criteria include its VQFN thermal performance (R_θJA = 52.9°C/W), latch-up immunity (>250 mA), ESD robustness (2000 V HBM), and compatibility with mixed-voltage 3.3 V/5 V system interconnects.

Technical Context

The SN74AHC157RGYR implements four independent 2:1 multiplexers sharing a common active-low strobe (G) and address select (A/B) input. When G is high, all Y outputs are forced low; when G is low, A/B selects between two 4-bit input sources (A-side or B-side) and routes them to the corresponding Y outputs without inversion.

Its CMOS AHC logic family ensures rail-to-rail output swing, low static current (ICC ≤ 40 µA at 5.5 V), and noise immunity via specified dynamic input thresholds (VIL(D) = 1.5 V, VIH(D) = 3.5 V at 5 V). Switching behavior is characterized across 2 V, 3.3 V, and 5 V supplies with load capacitances up to 50 pF.

Key Specifications

Pinout & Package

SN74AHC157RGYR uses a 16-pin VQFN package (RGY) with 0.5 mm pitch, 4 mm × 3.5 mm body size, and exposed thermal pad (connected to GND or left floating per datasheet guidance).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC157APWR and SN74AHC157D, SN74AHC157RGYR uniquely combines 2–5.5 V operation, industry-leading thermal performance (52.9°C/W), and active production status - making it the optimal choice for new industrial and automotive designs requiring voltage flexibility and compact thermal management.

Availability

SN74AHC157RGYR is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and test equipment requiring stable component supply, long-term lifecycle support, and RoHS-compliant VQFN packaging.

Supply support for SN74AHC157RGYR 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 decades of expertise in high-reliability logic families and automotive-grade qualification.

SN74AHC157RGYR belongs to the AHC advanced high-speed CMOS logic family, designed for low-power, high-noise-immunity digital signal routing in industrial, automotive, and communications systems where voltage flexibility and thermal efficiency are critical.

FAQ

What is the maximum clock/data rate supported by SN74AHC157RGYR?

SN74AHC157RGYR does not operate on a clock; it is asynchronous. Its maximum usable data rate depends on propagation delay and load capacitance. At VCC = 5 V and CL = 15 pF, t_PLH/t_PHL is 4.1 ns max, supporting clean signal transitions up to ~100 MHz in point-to-point routing. For reliable operation with bus loading, derate to ≤50 MHz with proper termination and layout.

Can SN74AHC157RGYR interface directly with 3.3 V microcontrollers while powered from 5 V?

Yes. SN74AHC157RGYR has 5.5 V-tolerant inputs, so 3.3 V logic levels from a microcontroller meet VIH (≥2.1 V) and VIL (≤0.9 V) specifications at VCC = 5 V. Outputs swing rail-to-rail (0 V to 5 V), so external level translation is required if driving 3.3 V-only receivers - but the SN74AHC157RGYR itself operates safely.

Is the thermal pad on SN74AHC157RGYR required to be soldered to ground?

No. Per TI's SCLS345L datasheet, the thermal pad on SN74AHC157RGYR "can be connected to GND or left floating" and must not be connected to any other signal or supply. Connecting it to GND improves thermal performance (lower R_θJA), but floating is electrically acceptable and commonly used in prototypes or space-constrained layouts.

Does SN74AHC157RGYR support hot insertion or live swapping?

No. SN74AHC157RGYR is not hot-swap rated. Its absolute maximum ratings specify VI and VO limits relative to VCC and GND, and no power sequencing or current-limiting features are included. Applying input signals before VCC stabilization risks latch-up or damage. Always power VCC before applying inputs.

How does the strobe (G) pin function in SN74AHC157RGYR compared to enable pins on other muxes?

In SN74AHC157RGYR, the G pin is an active-low output strobe: when high, all Y outputs are forced low (not high-impedance). This differs from 3-state enable pins. To achieve high-impedance outputs, external tri-state buffers or a different device (e.g., SN74AHC257) would be needed. G provides simple bus forcing, not isolation.