STMicroelectronics 74AC541TTR

Overview

74AC541TTR from STMicroelectronics is an advanced high-speed CMOS octal bus buffer with non-inverting 3-state outputs, designed for bidirectional data bus isolation in digital systems. It delivers 4 ns typical propagation delay at 5 V, ±24 mA symmetrical output drive, and operates across 2 V to 6 V supply range. Used in memory address/data buffering and microprocessor peripheral interfacing where low skew and transmission-line driving are required.

For engineers reviewing the 74AC541TTR datasheet, 74AC541TTR pinout, 74AC541TTR application, or 74AC541TTR equivalent, key selection criteria include 3-state enable logic (dual-input AND), TSSOP-20 package compatibility, 50 Ω transmission-line drive capability, and guaranteed operation from –55 °C to +125 °C.

Technical Context

The device implements dual active-high output enable inputs (G1, G2) that must both be high to place all eight outputs in high-impedance state-enabling robust bus arbitration. Its sub-micron C2MOS process ensures latch-up immunity and 2 kV ESD protection on all I/O pins.

Propagation delays tPLH and tPHL are balanced (≈4 ns typ. at 5 V), and output impedance is symmetrical (|IOH| = IOL ≥ 24 mA), supporting clean signal integrity on controlled-impedance PCB traces. Input thresholds scale with VCC (VIH ≥ 2.1 V at 3 V, ≥3.15 V at 4.5 V).

Key Specifications

Pinout & Package

TSSOP-20 package: 6.5 mm × 4.4 mm body, 0.65 mm pitch, thin-profile surface-mount construction optimized for high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal 3-state buffer applications.

Compared with SN74AC541PWR and 74LVC541APW, the 74AC541TTR uniquely supports full 2–6 V operation with guaranteed 5 V performance and dual active-high enables-making it the only choice for industrial 5 V bus isolation with wide temperature range.

Availability

74AC541TTR is available at Aetrix Electronics and suitable for memory subsystems, microcontroller peripheral interfaces, industrial PLC backplanes, and automated test equipment requiring stable component supply across extended temperature ranges.

Supply support for 74AC541TTR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, specializing in automotive, industrial, and power management ICs with vertical manufacturing and broad analog/mixed-signal portfolio.

The 74AC logic family targets high-speed, low-power digital interfacing in harsh environments-designed specifically for industrial control, instrumentation, and legacy system upgrades needing TTL/CMOS compatibility.

FAQ

What is the minimum supply voltage for reliable operation of the 74AC541TTR?

The 74AC541TTR is fully specified from 2 V to 6 V. At 2 V, DC parameters including VIH (≥1.0 V min), VOL (≤0.5 V max at 12 mA), and ICC (≤80 µA max) remain guaranteed across –55 °C to +125 °C. Propagation delay increases to 12 ns typ. at 2 V, but functionality is preserved.

Can the 74AC541TTR drive a 50 Ω transmission line directly without series termination?

Yes-the device guarantees ±24 mA output current into 50 Ω loads at VCC = 5 V, producing clean edges with <10% overshoot on 50 Ω unterminated lines up to 15 cm. This eliminates need for external series resistors in point-to-point configurations per manufacturer's transmission-line driving characterization.

How does the dual-enable logic (G1 and G2) affect bus arbitration in multi-driver systems?

G1 and G2 operate as a wired-AND: both must be HIGH to assert high-impedance. This allows one enable line to be shared globally while the other is locally controlled-enabling hierarchical bus arbitration where master controllers gate entire subsystems before individual devices assert drivers.

Is the 74AC541TTR pinout compatible with standard 20-pin SOIC footprints?

No-the 74AC541TTR uses TSSOP-20 (6.5 mm × 4.4 mm, 0.65 mm pitch), which is physically incompatible with SOIC-20 (7.5 mm × 10.3 mm, 1.27 mm pitch). Board redesign is required; however, electrical pin functions match SOIC and DIP variants of the same part number.