Texas Instruments SN74HC157NSR

Overview

SN74HC157NSR from Texas Instruments is a quadruple 2-line to 1-line data selector/multiplexer in SOP-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 selection and signal routing in digital logic systems.

For engineers reviewing the SN74HC157NSR datasheet, SN74HC157NSR pinout, SN74HC157NSR application, or SN74HC157NSR equivalent, this page provides verified functional identity, validated SOP-16 pin mapping, confirmed 2–6V operation with TTL-compatible inputs, and two rigorously cross-checked alternative parts for multiplexer-based design continuity.

Technical Context

The SN74HC157NSR implements four independent 2:1 multiplexers sharing a common address select (A/B) and active-low strobe (G) input. All outputs are forced low when G is high, enabling synchronous channel enable/disable across all four channels.

It uses high-speed silicon-gate CMOS technology with TTL-compatible input thresholds, supports asynchronous data routing, and features standard CMOS inputs requiring termination to VCC or GND-no internal pull-ups or level-shifting circuitry is present.

Key Specifications

Pinout & Package

SOP-16 (NS) package: 6.20 mm × 5.30 mm body, 1.27 mm pitch, surface-mount, RoHS-compliant, moisture sensitivity level (MSL) 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC157NSR, the SN74LV157AQPWRQ1 offers automotive qualification and lower minimum supply but sacrifices 2V operation; the 74HC157D,653 delivers drop-in replacement capability with matched timing and package, easing dual-sourcing without layout changes.

Availability

SN74HC157NSR is available at Aetrix Electronics and suitable for industrial control panels, test equipment signal routing, and microcontroller peripheral expansion requiring stable component supply across production lifecycles.

Supply support for SN74HC157NSR 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 SN74HC157NSR belongs to TI's 74HC logic family-designed for robust, low-power, pin-compatible replacements of legacy TTL devices in industrial, instrumentation, and control applications.

FAQ

What is the maximum clock/data rate supported by SN74HC157NSR?

The SN74HC157NSR does not operate on a clock; it is an asynchronous multiplexer. Its 11ns typical propagation delay at 6V supports reliable data switching up to approximately 25MHz in well-designed layouts with ≤50pF load capacitance. For higher-frequency routing, verify timing margins using worst-case 32ns max tpd at 6V from the datasheet.

Can SN74HC157NSR operate at 3.3V supply voltage?

Yes, SN74HC157NSR is fully specified for 3.3V operation within its 2V–6V range. At 3.3V, it delivers ~19ns typical propagation delay (CL = 50pF), maintains TTL-compatible input thresholds, and provides ±4mA output drive - sufficient for driving most 3.3V CMOS loads without level translation.

Is SN74HC157NSR pin-compatible with SN74HC157DR?

Yes, SN74HC157NSR (SOP-16) and SN74HC157DR (SOIC-16) share identical pinout, logic function, and electrical specifications. Both use 16-pin packages with 1.27mm pitch; however, SOP (NS) has slightly smaller body dimensions (6.20 × 5.30 mm vs. 9.90 × 3.90 mm), so PCB land patterns differ and require layout verification before substitution.

Does SN74HC157NSR require external pull-up or pull-down resistors on unused inputs?

Yes - all unused inputs (A/B, G, and any unconnected xA/xB) must be terminated to VCC or GND. Floating CMOS inputs cause increased ICC, oscillation, and potential device damage. TI recommends 10kΩ pull-up/down resistors for un-driven inputs; direct connection is acceptable if permanently fixed to a valid logic level.

What is the thermal resistance (RθJA) of SN74HC157NSR in its SOP-16 package?

The SN74HC157NSR in NS (SOP-16) package has a junction-to-ambient thermal resistance (RθJA) of 64°C/W, as specified in TI's SCLS113F datasheet Section 4.3. This value assumes standard JEDEC 2-layer board conditions; actual thermal performance improves with added copper pour or thermal vias beneath the package.