Texas Instruments SN74AHC157DRG4

Overview

SN74AHC157DRG4 from Texas Instruments is a quadruple 2-line to 1-line data selector/multiplexer in SOIC-16 package, operating from 2 V to 5.5 V supply, with 8 ns typical propagation delay at 5 V, ±8 mA output drive, and true (non-inverted) data routing. It serves as a digital signal path selector in bus management, data routing, and address decoding circuits within industrial control and instrumentation systems.

For engineers reviewing the SN74AHC157DRG4 datasheet, SN74AHC157DRG4 pinout, SN74AHC157DRG4 application, or SN74AHC157DRG4 equivalent, key selection criteria include its 16-pin SOIC package, active-low strobe (G) control, A/B select logic, quad-channel true-output architecture, and compatibility with mixed-voltage 3.3 V/5 V digital interfaces.

Technical Context

The SN74AHC157DRG4 implements four independent 2:1 multiplexers sharing a common active-low strobe (G) input and a single address select (A/B) input. When G is high, all Y outputs are forced low regardless of inputs; when G is low, each Y output reflects the selected input (1A/1B, 2A/2B, etc.) based on A/B state.

Its CMOS AHC logic family ensures rail-to-rail output swing, low static current (≤40 µA at 5.5 V), and robust ESD protection (±2000 V HBM). The device supports both 3.3 V and 5 V operation without level-shifting, with propagation delays specified down to 4.1 ns (tPLH, A→Y, VCC = 5 V, CL = 15 pF).

Key Specifications

Pinout & Package

SN74AHC157DRG4 is housed in a 16-pin SOIC (D) package measuring 9.90 mm × 6.00 mm (body: 9.90 mm × 3.90 mm), RoHS-compliant, with NIPDAU lead finish and MSL Level-1 rating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LV157A and 74HC157, SN74AHC157DRG4 delivers superior speed (4.1 ns vs. ≥12 ns), lower quiescent current (40 µA vs. ≥80 µA), and broader voltage flexibility-making it optimal for modern mixed-voltage industrial controllers requiring deterministic timing and low power.

Availability

SN74AHC157DRG4 is available at Aetrix Electronics and suitable for industrial automation, test instrumentation, and embedded control applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for SN74AHC157DRG4 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 experience in high-reliability industrial and automotive IC design.

The SN74AHC157DRG4 belongs to TI's advanced high-speed CMOS (AHC) logic family, engineered for low-power, high-speed digital interfacing in demanding industrial and instrumentation applications.

FAQ

What is the function of the G (strobe) pin on the SN74AHC157DRG4?

The G pin on the SN74AHC157DRG4 is an active-low strobe that globally enables or disables the multiplexer function. When G is high, all four Y outputs are forced low regardless of A/B or data inputs. When G is low, the device performs normal 2:1 selection per channel based on the A/B address line. This allows synchronized gating of all four outputs in time-critical control sequences, and is explicitly defined in the Function Table of the SN74AHC157DRG4 datasheet.

Does the SN74AHC157DRG4 support 3.3 V logic levels?

Yes, the SN74AHC157DRG4 fully supports 3.3 V operation: its recommended VCC range is 2 V to 5.5 V, and all electrical characteristics-including VIH (2.1 V min at VCC = 3 V), VOL (0.1 V max), and tPLH (6.2 ns typ at 3.3 V)-are specified at 3.3 V ±0.3 V. It interfaces directly with 3.3 V microcontrollers and FPGAs without level shifting, and its AHC logic family ensures clean signal integrity at this voltage.

What is the maximum output current capability of the SN74AHC157DRG4?

The SN74AHC157DRG4 provides ±8 mA output drive capability at VCC = 5 V, as specified in the Recommended Operating Conditions table under IOL/IOL limits. At 3.3 V, it delivers ±4 mA. These values represent guaranteed steady-state sink/source current per output pin, sufficient to drive standard TTL loads or fan-out to ≥10 CMOS inputs. Exceeding these limits risks output voltage degradation or thermal stress.

Is the SN74AHC157DRG4 pin-compatible with older 74-series multiplexers?

Yes, the SN74AHC157DRG4 is pin-compatible with industry-standard 74157 and 74HC157 devices in the same SOIC-16 package. Pin numbering, function mapping (A/B, G, 1A–4B, 1Y–4Y, VCC, GND), and logic behavior match exactly. However, differences in speed, drive strength, and supply range mean electrical compatibility must be verified per application-especially when replacing HC or LS variants in existing designs.

How should unused inputs be handled on the SN74AHC157DRG4?

All unused inputs on the SN74AHC157DRG4-including A/B, G, and any unconnected 1A–4B pins-must be tied to a valid logic level (VCC or GND) to prevent floating states that cause increased ICC, noise susceptibility, or erratic output behavior. TI's application note SCBA004 explicitly mandates this practice. Leaving inputs unconnected violates the Recommended Operating Conditions and may result in undefined operation or accelerated device aging.