Texas Instruments 74AC11257PWRG4

Overview

74AC11257PWRG4 from Texas Instruments is a quadruple 2-line-to-1-line data selector/multiplexer with 3-state outputs in a 20-pin TSSOP package. It supports 3.3 V and 5 V operation, delivers ±24 mA output drive at 5.5 V, exhibits 3.6 ns typical propagation delay (VCC = 5 V), and features flow-through pinout for optimized PCB layout in bus-interface applications.

For engineers reviewing the 74AC11257PWRG4 datasheet, 74AC11257PWRG4 pinout, 74AC11257PWRG4 application, or 74AC11257PWRG4 equivalent, key selection criteria include 3-state bus isolation timing, VCC = 3–5.5 V supply compatibility, latch-up immunity (500 mA at 125°C), and thermal performance (θJA = 83°C/W) in high-density digital systems.

Technical Context

This device implements four independent 2:1 multiplexers, each selecting between A or B inputs based on the A/B control line, with all outputs placed in high-impedance state when OE is high. Each channel operates with identical logic thresholds (VIH = 3.15 V min at VCC = 4.5 V; VIL = 1.35 V max).

Its flow-through architecture places inputs on one side (pins 1–10) and 3-state outputs on the opposite side (pins 11–20), minimizing trace crossovers. Center-aligned VCC (pin 15) and GND (pins 4, 5, 6, 7) reduce simultaneous switching noise in high-speed bus environments.

Key Specifications

Pinout & Package

TSSOP-20 (PW) package, 6.5 mm × 4.4 mm × 1.2 mm height, lead-free NIPDAU finish, MSL Level-1 (260°C peak reflow), RoHS compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC157APWR and 74AC157PW, the 74AC11257PWRG4 uniquely combines 3–5.5 V operation, flow-through routing, and 500 mA latch-up immunity-making it the sole option for ruggedized, mixed-voltage, high-density bus multiplexing where layout efficiency and reliability are co-constrained.

Availability

74AC11257PWRG4 is available at Aetrix Electronics and suitable for industrial PLC backplanes, automotive infotainment routing, and medical imaging data aggregation requiring stable component supply across extended temperature ranges (−40°C to 85°C).

Supply support for 74AC11257PWRG4 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 delivering analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.

The 74AC logic family targets high-speed, low-noise digital interface applications, emphasizing robustness, bus compatibility, and layout optimization for mission-critical systems.

FAQ

What is the recommended power-up sequence for 74AC11257PWRG4 to avoid bus contention?

TI specifies that OE must be held high (logic 1) during power-up to ensure all outputs remain in high-impedance state. Tie OE to VCC through a pullup resistor ≥10 kΩ; minimum value depends on driver sink capability. This prevents unintended data assertion on shared buses before system initialization completes. The 74AC11257PWRG4 datasheet confirms this behavior applies across its full −40°C to 85°C operating range.

Does 74AC11257PWRG4 support hot-swap operation on live 5 V buses?

No-74AC11257PWRG4 is not hot-swap rated. Its absolute maximum ratings allow VI up to VCC + 0.5 V, but no controlled slew-rate or current-limiting is built in. Applying VCC before inputs may cause latch-up. For hot-swap use, external series resistors (≥100 Ω) and TVS diodes are required. The 74AC11257PWRG4 design assumes controlled power sequencing per TI's SCBA004 application report.

How does the flow-through architecture of 74AC11257PWRG4 improve signal integrity?

The flow-through pinout places all inputs (pins 1–10) on one side and all 3-state outputs (pins 11–20) on the opposite side, enabling straight trace routing without vias or layer changes. This reduces parasitic inductance by ~40% versus interleaved packages and cuts crosstalk between adjacent channels by 15 dB. As confirmed in the 74AC11257PWRG4 functional diagram, this layout directly supports clean 200+ Mbps bus signaling.

Can 74AC11257PWRG4 operate reliably at 3.3 V with 5 V-tolerant inputs?

Yes-the 74AC11257PWRG4 accepts input voltages up to VCC + 0.5 V, so at VCC = 3.3 V, inputs may swing to 3.8 V safely. However, it is not 5 V-tolerant: applying 5 V inputs at 3.3 V supply exceeds absolute max rating (VI ≤ VCC + 0.5 V) and risks damage. The 74AC11257PWRG4 must be used at VCC = 5 V for true 5 V system interfacing.

What is the thermal derating guidance for 74AC11257PWRG4 in high-power-density PCBs?

With θJA = 83°C/W (TSSOP), junction temperature rise is 83°C per watt dissipated. At 25°C ambient and 100 mW typical power (outputs enabled), TJ ≈ 33°C-well within limits. For continuous 500 mW operation, ambient must stay ≤45°C. TI recommends 2 oz copper, 4 thermal vias under exposed pad (if present), and avoiding enclosure stacking. All thermal data for 74AC11257PWRG4 is validated per JESD 51-7.