Texas Instruments SN74AHC2G157HDCTR

Overview

SN74AHC2G157HDCTR from Texas Instruments is a dual 2-line-to-1-line data selector/multiplexer in an 8-pin DCT package, operating from 2.0 V to 5.5 V V_CC, with typical propagation delay of 6.2 ns at 3.0 V/15 pF, I_CC(max) = 2 µA at 25 °C, and guaranteed operation from –40 °C to +85 °C. It routes true logic from one of two inputs (A or B) to output Y based on select input A/B, with active-low enable G controlling output state.

For engineers reviewing the SN74AHC2G157HDCTR datasheet, SN74AHC2G157HDCTR pinout, SN74AHC2G157HDCTR application, or SN74AHC2G157HDCTR equivalent, key selection criteria include its dual-channel 2:1 multiplexing function, rail-to-rail input tolerance (VIH max = 5.5 V), low static current, fast switching at 3.3 V and 5 V, and compact DCT package for space-constrained digital logic routing.

Technical Context

The SN74AHC2G157HDCTR implements positive-logic 2:1 multiplexing per channel using complementary AHC CMOS technology, supporting independent selection control via A/B and global enable via G. Each channel drives both true (Y) and inverted (Y̅) outputs simultaneously.

It features TTL-compatible input thresholds across V_CC = 2–5.5 V, with VIH(min) = 1.5 V (at V_CC = 2 V), VIL(max) = 0.5 V (at V_CC = 2 V), and full 5.5-V absolute input voltage rating - enabling mixed-voltage interfacing without level shifters.

Key Specifications

Pinout & Package

SN74AHC2G157HDCTR uses an 8-pin DCT (thin shrink small-outline package) measuring 2.95 mm × 2.80 mm × 1.1 mm, optimized for high-density PCB layouts and automated assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 2-line-to-1-line multiplexer applications.

Compared with SN74LVC2G157DCTR and MC74VHC2G157DTT1G, the SN74AHC2G157HDCTR delivers the lowest I_CC and fastest propagation at 3 V, making it optimal for power-sensitive, timing-critical 3.3 V digital routing where rail-to-rail input tolerance is essential.

Availability

SN74AHC2G157HDCTR is available at Aetrix Electronics and suitable for industrial sensor interfaces, automotive body control modules, and low-power microcontroller peripheral selection requiring stable component supply and long-term manufacturability.

Supply support for SN74AHC2G157HDCTR 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The SN74AHC2G157HDCTR belongs to TI's AHC logic family, engineered for high-speed, low-power, mixed-voltage digital signal routing in space-constrained embedded systems requiring robust DC and AC performance.

FAQ

What is the function of the G pin on the SN74AHC2G157HDCTR?

The G pin on the SN74AHC2G157HDCTR is the active-low enable input. When G is high, both outputs Y and Y̅ are forced low and high respectively, regardless of A, B, or A/B states. When G is low, the device operates as a 2:1 multiplexer, routing either A or B to Y/Y̅ based on the A/B select signal. This enables global output disable for bus contention avoidance or power gating in the SN74AHC2G157HDCTR.

Does the SN74AHC2G157HDCTR support 5 V logic levels when powered from 3.3 V?

No - the SN74AHC2G157HDCTR does not support 5 V-tolerant inputs when V_CC = 3.3 V. Its absolute maximum input voltage is 6.0 V, but its input thresholds scale with V_CC. At V_CC = 3.3 V, VIH(min) = 2.1 V and VIL(max) = 0.9 V. Applying 5 V inputs risks exceeding recommended operating conditions and may cause excessive current or reliability degradation in the SN74AHC2G157HDCTR.

Can the SN74AHC2G157HDCTR drive a 50 pF load at 10 MHz without signal integrity issues?

Yes - the SN74AHC2G157HDCTR specifies switching characteristics up to CL = 50 pF, with t_PLH/t_PHL = 10.9 ns (typ) at V_CC = 3.3 V. At 10 MHz (100 ns period), this leaves >89 ns of valid setup/hold margin per edge. Combined with ±25 mA drive strength and 20 pF power dissipation capacitance, the SN74AHC2G157HDCTR maintains clean edges and low jitter under these conditions.

Is the SN74AHC2G157HDCTR pin-compatible with the SN74AHC157?

No - the SN74AHC2G157HDCTR is not pin-compatible with the SN74AHC157. The SN74AHC157 is a quad 2:1 multiplexer in a 16-pin SOIC package, while the SN74AHC2G157HDCTR is a dual-channel version in an 8-pin DCT package with different pin assignments (e.g., dedicated Y̅ output, shared G). Interchange requires PCB redesign and layout changes for the SN74AHC2G157HDCTR.

What is the maximum junction temperature for continuous operation of the SN74AHC2G157HDCTR?

The SN74AHC2G157HDCTR has a maximum junction temperature (T_J) of 150 °C, derived from its absolute maximum ratings and thermal characterization. Under typical PCB conditions (750-mil trace, still air), the DCT package dissipates up to 300 mW at T_A = 25 °C. For sustained operation, thermal design must ensure T_J ≤ 150 °C - verified using θ_JA = 220 °C/W (typical for DCT) and actual power dissipation in the SN74AHC2G157HDCTR.