Texas Instruments SN74HC157NE4

Overview

SN74HC157NE4 from Texas Instruments is a quadruple 2-line to 1-line data selector/multiplexer in 16-pin PDIP package, operating from 2V to 6V supply, delivering 11ns typical propagation delay at 5V, ±6mA output drive, and 80µA max ICC - used for synchronous 4-bit bus routing in digital control logic and address/data path selection.

For engineers reviewing the SN74HC157NE4 datasheet, SN74HC157NE4 pinout, SN74HC157NE4 application, or SN74HC157NE4 equivalent, this page provides verified functional mode behavior, validated PDIP-16 terminal mapping, confirmed 2–6V operation with TTL-compatible inputs, and real-world multiplexer timing under 50pF load conditions.

Technical Context

The SN74HC157NE4 implements four independent 2:1 multiplexers sharing one common address select (A/B) input and one active-low strobe (G) input; all outputs go low when G is high, regardless of A/B or data inputs. It uses high-speed silicon-gate CMOS technology with TTL-compatible input thresholds.

Each channel selects between two inputs (A or B) based on the A/B logic level, with output Y reflecting the selected input only when G is low. Input leakage is ≤1µA max, and output drive capability is ±6mA at 5V with VOL ≤0.26V at 6mA sink current.

Key Specifications

Pinout & Package

SN74HC157NE4 is housed in a 16-pin plastic dual in-line package (PDIP-N), 19.31 mm × 6.35 mm body size, through-hole mountable with 0.3-inch row spacing and standard DIP footprint compatibility.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC157NE4, SN74HC158N requires control logic adaptation due to inverted enable and output polarity, whereas CD74HC157E offers identical functionality and mechanical fit with guaranteed long-term availability under alternate TI part numbering.

Availability

SN74HC157NE4 is available at Aetrix Electronics and suitable for industrial control systems, automated test equipment, PLC I/O modules, and legacy system upgrades requiring stable component supply and through-hole assembly compatibility.

Supply support for SN74HC157NE4 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 logic families.

The SN74HC157NE4 belongs to TI's 74HC high-speed CMOS logic series, designed specifically for low-power, pin-compatible replacements of TTL devices in industrial, automotive, and communications infrastructure applications.

FAQ

What is the maximum operating temperature for SN74HC157NE4?

The SN74HC157NE4 is rated for operation from -40°C to +85°C ambient temperature. This industrial-grade specification is validated per TI's Recommended Operating Conditions and applies to the PDIP package variant. The device maintains full electrical performance across this range, including propagation delay stability and output drive capability. Always verify thermal derating when operating near maximum ambient with sustained output loading.

Does SN74HC157NE4 support 3.3V logic levels?

Yes, SN74HC157NE4 fully supports 3.3V operation: its supply range is 2V–6V, and input thresholds scale with VCC (VIH ≥ 2.0V at 3.3V). At 3.3V supply, it delivers ~4.5mA output drive and maintains 11ns typical tpd with 50pF load. Inputs accept standard 3.3V CMOS or LVTTL signals without level shifting, making SN74HC157NE4 ideal for mixed-voltage board designs.

Can unused inputs on SN74HC157NE4 be left floating?

No - all unused inputs on SN74HC157NE4 must be terminated to either VCC or GND. Floating CMOS inputs cause excessive current draw, potential oscillation, and increased EMI. TI specifies ≤1µA leakage, but uncontrolled input voltage violates recommended operating conditions. For unused A/B or G pins, use 10kΩ pull-up or pull-down resistors; for unused data inputs (e.g., 1A, 1B), tie directly to VCC or GND depending on desired default state.

What is the purpose of the G (strobe) pin on SN74HC157NE4?

The G pin on SN74HC157NE4 is an active-low strobe that forces all four Y outputs low regardless of A/B or data input states. This enables global bus disable, conflict prevention during data handshaking, or synchronization with system clocks. When G is high, outputs remain low even if A/B changes - critical for glitch-free bus arbitration in multi-master systems. Its function is distinct from enable pins on other multiplexers like SN74HC158.

Is SN74HC157NE4 pin-compatible with SN74LS157?

Yes - SN74HC157NE4 is a direct pin-compatible, functionally equivalent CMOS upgrade for SN74LS157. Both share identical PDIP-16 pinout, logic function, and terminal assignments (A/B, G, 1A–4B, 1Y–4Y, VCC, GND). SN74HC157NE4 improves on LS-series with lower power (80µA vs. ~15mA ICC), higher noise immunity, wider voltage range (2–6V vs. 4.75–5.25V), and faster speed (11ns vs. 25ns tpd), with no PCB changes required.