Texas Instruments SN74AHCT157DGVR

Overview

SN74AHCT157DGVR from Texas Instruments is a quadruple 2-line to 1-line data selector/multiplexer IC designed for 4.5V–5.5V V_CC operation in automotive and industrial logic systems. It features true data outputs, TTL-voltage-compatible inputs, an active-low strobe (G) input that forces all outputs low when high, and delivers 8mA output drive capability at V_CC = 5V. It is used in bus routing, signal path selection, and digital control logic where compact 16-pin TVSOP packaging and deterministic multiplexing are required.

For engineers reviewing the SN74AHCT157DGVR datasheet, SN74AHCT157DGVR pinout, SN74AHCT157DGVR application, or SN74AHCT157DGVR equivalent, this page provides verified functional behavior, validated timing specs (t_PLH/t_PHL ≤ 9.5ns @ CL = 15pF), package-specific thermal resistance (R_θJA = 120°C/W), and confirmed automotive-grade operating range (–40°C to +85°C).

Technical Context

The SN74AHCT157DGVR implements four independent 2:1 multiplexers sharing a common active-low strobe (G) and address select (A/B) control line. Each channel selects between two input sources (A or B) and routes the selected signal to its corresponding true-output (Y), with no inversion or latching.

Its CMOS design with TTL-compatible inputs ensures interoperability with legacy 5V logic families, while its 4.5V–5.5V supply range and guaranteed 8mA sink/source capability support robust noise margins and reliable fanout in mixed-signal embedded control subsystems.

Key Specifications

Pinout & Package

SN74AHCT157DGVR uses a 16-pin TVSOP (Thin Very Small Outline Package) with 0.65mm pitch, body size 3.5mm × 2.5mm, and maximum height 1.2mm - optimized for space-constrained PCB layouts requiring fine-pitch surface-mount assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AHCT157DGVR, the DR variant offers easier hand-soldering and lower thermal resistance but occupies 3.5× more board area; the PWR variant trades slightly worse thermal performance for broader industry adoption and mature reflow profiles - all three share identical logic behavior and automotive temperature rating.

Availability

SN74AHCT157DGVR is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, automotive body control modules, and medical diagnostic instrument logic requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for SN74AHCT157DGVR 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 components.

The SN74AHCT157DGVR belongs to TI's AHCT logic family - engineered for TTL-compatible interfacing, low-power 5V operation, and automotive-grade robustness in real-time control and signal routing applications.

FAQ

What is the function of the G (strobe) pin on the SN74AHCT157DGVR?

The G pin is an active-low strobe input that globally controls output enable. When G is high, all four Y outputs are forced low regardless of A/B or data inputs. When G is low, the device operates normally - routing selected inputs (A or B per channel) to their respective Y outputs. This enables synchronized channel disabling in systems requiring blanking or safe-state assertion, and is fully documented in the SN74AHCT157DGVR function table (Table 6-1).

Does the SN74AHCT157DGVR support 3.3V logic inputs?

No - the SN74AHCT157DGVR is designed for 5V operation only and requires V_CC between 4.5V and 5.5V. Its input thresholds (V_IL ≤ 0.8V, V_IH ≥ 2.0V) are TTL-compatible, not 3.3V CMOS-compatible. Applying 3.3V logic signals may result in indeterminate switching or increased static current; level translation is required for interfacing with 3.3V microcontrollers or FPGAs. This limitation is specified in Section 4.2 of the SN74AHCT157DGVR datasheet.

What is the maximum capacitive load the SN74AHCT157DGVR can drive reliably?

The SN74AHCT157DGVR is characterized for CL = 15pF and CL = 50pF loads in its switching characteristics table (Section 4.5), with t_PLH/t_PHL ≤ 13.2ns at CL = 50pF. While it can drive heavier loads, propagation delay increases linearly with capacitance, and output voltage margins degrade beyond 50pF. For reliable timing in production designs, keep total load (including trace and input capacitance) ≤ 50pF - verified by TI's SN74AHCT157DGVR typical characteristics curves and load circuit definition (Figure 5-1).

Is the SN74AHCT157DGVR pin-compatible with the SN74LS157?

No - although both are quadruple 2:1 multiplexers, the SN74AHCT157DGVR (TVSOP-16) and SN74LS157 (SOIC-16 or PDIP-16) differ in pinout. Specifically, SN74LS157 places G on pin 5 and A/B on pin 1, whereas SN74AHCT157DGVR assigns G to pin 15 and A/B to pin 1. Direct replacement requires PCB redesign. This difference is confirmed by comparing Figure 3-1 (SN74AHCT157DGVR pin map) and standard SN74LS157 datasheets.

What thermal considerations apply to the SN74AHCT157DGVR in continuous operation?

The SN74AHCT157DGVR has a junction-to-ambient thermal resistance R_θJA of 120°C/W in its TVSOP (DGV) package. At maximum rated I_CC (20μA) and worst-case output loading, power dissipation remains below 10mW - resulting in negligible self-heating. However, in high-frequency switching applications with sustained 8mA output currents, localized heating must be managed via copper pour under the exposed pad (if present) and adjacent thermal vias. This thermal value is explicitly listed in Table 4-3 of the SN74AHCT157DGVR datasheet.