Texas Instruments SN74LVC157ADRG3

Overview

SN74LVC157ADRG3 from Texas Instruments is a quadruple 2-line to 1-line data selector/multiplexer in 16-pin SOIC (D) package, operating from 1.65V to 3.6V supply, with 5.2ns max propagation delay at 3.3V, 5.5V-tolerant inputs, and –40°C to 125°C temperature range. It routes four independent 2:1 data paths under common address (A/B) and strobe (G) control, used in bus multiplexing, signal routing, and level translation in mixed-voltage digital systems.

For engineers reviewing the SN74LVC157ADRG3 datasheet, SN74LVC157ADRG3 pinout, SN74LVC157ADRG3 application, or SN74LVC157ADRG3 equivalent, key selection criteria include its 3.3V/5V I/O compatibility, low propagation delay across voltage range, guaranteed operation up to 125°C, and SOIC-16 footprint for legacy board compatibility and manual assembly.

Technical Context

The SN74LVC157ADRG3 implements true (non-inverting) data selection logic with a shared active-low output enable (G) and a common address select (A/B) controlling all four 2:1 channels. Each channel selects either input A or B based on A/B state when G is low; all outputs go low when G is high.

Its CMOS LVC process enables 5.5V-tolerant inputs while operating from 1.65V–3.6V V_CC, supporting bidirectional voltage translation between 3.3V and 5V domains without external components. Output drive strength scales with V_CC, delivering ±24mA at 3.0V and ±4mA at 1.65V.

Key Specifications

Pinout & Package

SN74LVC157ADRG3 uses the 16-pin SOIC (D) package (9.90 mm × 6.00 mm body, 9.90 mm × 3.90 mm footprint), with gull-wing leads and RoHS-compliant matte tin (Sn) lead finish. Thermal pad is absent; no internal thermal slug.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar data selector/multiplexer applications.

Compared with SN74LVC157ADR and 74LVC157PW,118, the SN74LVC157ADRG3 provides unique combination of Sn lead finish for optimal wetting in lead-free reflow, full 125°C qualification, and guaranteed 5.2ns speed at 3.3V - making it preferred for automotive and industrial deployments requiring long-term reliability and process consistency.

Availability

SN74LVC157ADRG3 is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and test equipment requiring stable component supply, long-lifecycle support, and RoHS-compliant SOIC packaging.

Supply support for SN74LVC157ADRG3 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 interface and signal-path ICs.

The SN74LVC157ADRG3 belongs to TI's LVC logic family, designed specifically for low-voltage, high-speed, mixed-signal interfacing in space-constrained and thermally demanding applications.

FAQ

What is the maximum clock/data frequency supported by SN74LVC157ADRG3?

The SN74LVC157ADRG3 does not operate on a clock; it is asynchronous. Its maximum usable data rate is determined by propagation delay and setup/hold timing. With 5.2ns max t_pd at 3.3V and typical input transition rates ≤10 ns/V, it reliably handles data switching up to ~100MHz in well-designed PCB layouts with proper termination and decoupling. The SN74LVC157ADRG3 datasheet specifies no minimum pulse width, but practical limits arise from board-level signal integrity.

Can SN74LVC157ADRG3 be used to translate 5V signals to a 1.8V microcontroller?

No - the SN74LVC157ADRG3 accepts 5.5V-tolerant inputs but requires V_CC ≥1.65V to operate. Its outputs swing from GND to V_CC, so with V_CC = 1.8V, outputs are 0–1.8V, compatible with 1.8V logic. However, driving a 1.8V MCU input directly from SN74LVC157ADRG3 outputs is valid; driving 5V signals *into* SN74LVC157ADRG3 while powered at 1.8V is also valid due to 5.5V-tolerant inputs. The SN74LVC157ADRG3 itself does not generate 5V levels.

Is SN74LVC157ADRG3 pin-compatible with older 74LS157 or 74HC157 devices?

No - SN74LVC157ADRG3 uses the same 16-pin SOIC (D) package and identical pinout as SN74LS157 and SN74HC157, but electrical behavior differs significantly. Unlike bipolar LS or CMOS HC, the SN74LVC157ADRG3 has 5.5V-tolerant inputs, lower drive strength at 5V (it's not 5V-supplied), and different voltage thresholds. Direct replacement requires verifying V_CC, loading, and timing margins; the SN74LVC157ADRG3 is not a drop-in substitute without design review.

What is the purpose of the G (strobe) pin on SN74LVC157ADRG3?

The G pin is an active-low output enable that overrides all channel selection. When G is high, all four Y outputs are forced low regardless of A/B state or input values - effectively disabling the device's output drivers. When G is low, normal 2:1 selection occurs per A/B. This allows multiple SN74LVC157ADRG3 devices to share a common bus, with only one enabled at a time, preventing contention. G is essential for bus arbitration and power-aware gating.

Does SN74LVC157ADRG3 require external pull-up or pull-down resistors on unused inputs?

Yes - all unused inputs (including A/B and G) must be held at a defined logic level (V_CC or GND) to prevent floating nodes, which cause increased ICC, noise susceptibility, and potential latch-up. TI explicitly states this in Section 4.3/4.4 of the SN74LVC157ADRG3 datasheet. Leaving inputs unconnected violates recommended operating conditions and risks erratic behavior. Use 10kΩ resistors unless timing constraints demand stronger biasing.