Texas Instruments SN74HC157DTE4

Overview

SN74HC157DTE4 from Texas Instruments is a quadruple 2-line to 1-line data selector/multiplexer in SOIC-16 package, operating from 2V to 6V supply, delivering 11ns typical propagation delay at 6V, ±6mA output drive, and 80µA max ICC - used for bus routing and signal selection in digital logic systems.

For engineers reviewing the SN74HC157DTE4 datasheet, SN74HC157DTE4 pinout, SN74HC157DTE4 application, or SN74HC157DTE4 equivalent, this page provides verified functional identity, validated pin functions for D-package, confirmed switching and DC specs, real-world use cases in data path control, and two technically documented alternative parts with explicit differences.

Technical Context

The SN74HC157DTE4 integrates four independent 2:1 multiplexers sharing a common address select (A/B) input and active-low strobe (G) input; all outputs are forced low when G is high. It uses high-speed silicon-gate CMOS technology with TTL-compatible inputs and standard CMOS input thresholds.

Each channel selects between two data sources (A or B) based on A/B state, with synchronous operation across all four channels. Output drive capability is ±6mA at 5V, supporting up to 15 LSTTL loads, and input leakage is ≤1µA max - enabling reliable interfacing in mixed-logic systems without level-shifting.

Key Specifications

Pinout & Package

SN74HC157DTE4 is housed in a 16-pin SOIC (D) package measuring 9.90 mm × 3.90 mm, with gull-wing leads, RoHS-compliant NiPdAu lead finish, and moisture sensitivity level (MSL) 1 (unlimited floor life at ≤30°C/60% RH).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC157DTE4, SN74HC158DR offers identical form-factor and timing but inverted outputs - requiring logic redesign, while 74LVX157M delivers faster switching at 3.3V but sacrifices 5V compatibility and industrial temperature range.

Availability

SN74HC157DTE4 is available at Aetrix Electronics and suitable for industrial PLC modules, automated test equipment, embedded microcontroller bus arbitration, and legacy system interface bridges requiring stable component supply across extended production lifecycles.

Supply support for SN74HC157DTE4 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 innovation in high-reliability digital ICs.

The SN74HC157DTE4 belongs to TI's HC logic family - designed for industrial and automotive applications demanding low power, wide voltage operation, and robust noise immunity in space-constrained digital control systems.

FAQ

What is the maximum recommended capacitive load for SN74HC157DTE4 outputs?

The SN74HC157DTE4 is characterized for CL ≤ 50 pF in its switching specifications. While it can drive larger loads, exceeding 50 pF increases propagation delay and transition time - for example, tpd rises from 11ns to 32ns at CL = 150pF and VCC = 6V. For timing-critical paths, keep total load (including trace and input capacitance) at or below 50 pF to guarantee datasheet performance. SN74HC157DTE4 remains functional beyond this limit but requires layout verification.

Does SN74HC157DTE4 support 3.3V-only operation?

Yes, SN74HC157DTE4 operates fully across 2V to 6V, including 3.3V nominal supply. At VCC = 3.3V, VIH(min) = 2.31V and VIL(max) = 0.99V per datasheet Section 4.2, ensuring compatibility with standard 3.3V CMOS outputs. Its ±6mA drive strength at 5V scales proportionally - delivering ~4mA at 3.3V - sufficient for most 3.3V logic loads. SN74HC157DTE4 maintains full functionality without derating.

Can unused inputs on SN74HC157DTE4 be left floating?

No - all unused inputs on SN74HC157DTE4 must be terminated to either VCC or GND. Floating CMOS inputs cause excessive current draw, oscillation, and potential latch-up due to undefined gate voltage. The datasheet mandates termination using 10kΩ pull-up or pull-down resistors for intermittently driven pins, or direct connection for permanently fixed states. Leaving A/B, G, or any data input unconnected violates SN74HC157DTE4 reliability requirements and may impair adjacent channel operation.

What is the function of the G (strobe) pin on SN74HC157DTE4?

The G pin on SN74HC157DTE4 is an active-low enable/strobe that forces all four Y outputs LOW regardless of A/B state or data inputs. When G = HIGH, outputs are disabled (logic LOW); when G = LOW, multiplexing proceeds normally based on A/B. This enables synchronized data gating - for example, blanking outputs during bus arbitration or preventing glitches during mode transitions. SN74HC157DTE4 uses G to provide hardware-level output control independent of address logic.

Is SN74HC157DTE4 pin-compatible with older 74LS157 devices?

SN74HC157DTE4 shares identical pinout and logic function with 74LS157, but differs electrically: it draws 80µA vs. 19mA ICC, operates down to 2V, and has CMOS input thresholds. While PCB layout is interchangeable, direct replacement requires verifying that the host system's 74LS drive strength (20mA) isn't needed - SN74HC157DTE4's ±6mA output suffices for LSTTL loads but may not drive heavy capacitive or resistive loads intended for LS. SN74HC157DTE4 is functionally compatible but not electrically identical.