Texas Instruments SN74HC541PWG4

Overview

SN74HC541PWG4 from Texas Instruments is an octal non-inverting buffer/line driver with 3-state outputs, designed for bus interface and signal isolation in digital systems. It operates from 2 V to 6 V, delivers ±6 mA output drive at 5 V, exhibits typical propagation delay of 10 ns (VCC = 6 V, CL = 50 pF), and supports high-current bus driving up to 15 LSTTL loads - used in PC motherboard I/O expansion and LED segment drivers.

For engineers reviewing the SN74HC541PWG4 datasheet, SN74HC541PWG4 pinout, SN74HC541PWG4 application, or SN74HC541PWG4 equivalent, key selection criteria include its dual active-low output-enable architecture (OE1/OE2), data-flow-through pinout for PCB layout simplification, 3-state output control logic, and TSSOP-20 package compatibility with space-constrained embedded interfaces.

Technical Context

The SN74HC541PWG4 implements eight independent non-inverting buffers, each with true (non-inverted) input-to-output mapping. Its 3-state outputs are controlled by a two-input NOR gate: both OE1 and OE2 must be low to enable outputs; either high forces all Y1–Y8 into high-impedance state.

This device uses silicon-gate CMOS technology, enabling wide supply range (2–6 V), ultra-low static current (80 µA max ICC), and input leakage ≤1 µA. The pinout places all eight A inputs on one side and all eight Y outputs on the opposite side - a deliberate layout optimization that minimizes trace crossovers on dense PCBs.

Key Specifications

Pinout & Package

TSSOP-20 package (6.50 mm × 4.40 mm body size), thin shrink small-outline package with gull-wing leads - optimized for automated SMT assembly and high-density routing on compact PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC541PWG4, SN74HCT541PW offers superior noise immunity in 5 V TTL environments but lacks 2 V operation; 74LVC541APW delivers faster switching at lower voltage yet sacrifices 5 V compatibility - selection depends strictly on system supply architecture and interface voltage requirements.

Availability

SN74HC541PWG4 is available at Aetrix Electronics and suitable for PC motherboards, industrial PLC I/O modules, LED display subsystems, and wearable health sensor interfaces requiring stable component supply across extended production lifecycles.

Supply support for SN74HC541PWG4 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 logic ICs for industrial, automotive, and computing markets.

The SN74HC541PWG4 belongs to TI's HC (High-Speed CMOS) logic family, engineered for low-power, wide-supply-range digital interfacing in cost-sensitive and thermally constrained applications - particularly where bus isolation and 3-state control are required.

FAQ

What is the function of OE1 and OE2 on the SN74HC541PWG4?

The SN74HC541PWG4 uses two active-low output-enable inputs (OE1 and OE2) connected to a NOR gate. Both OE1 and OE2 must be low to enable the eight Y outputs; if either is high, all outputs enter high-impedance state. This dual-OE structure allows flexible bus control - for example, OE1 can serve as a global enable while OE2 acts as a local channel select, without requiring external logic.

Can the SN74HC541PWG4 operate at 3.3 V?

Yes, the SN74HC541PWG4 is fully specified for operation from 2 V to 6 V, including 3.3 V. At VCC = 3.3 V, it delivers ≥±4 mA output drive, maintains VIH ≤ 2.0 V and VIL ≥ 0.99 V, and achieves typical tpd of ~15 ns (CL = 50 pF). Its wide supply range makes it ideal for mixed-voltage systems bridging 3.3 V microcontrollers and 5 V peripherals.

Is the SN74HC541PWG4 pin-compatible with other TSSOP-20 octal buffers?

Yes - the SN74HC541PWG4 shares identical TSSOP-20 pinout and terminal functions with SN74HCT541PW, SN74LV541APW, and 74LVC541APW. All feature A1–A8 on pins 2–9, Y1–Y8 on pins 11–18, OE1/OE2 on pins 1/19, GND on pin 10, and VCC on pin 20. However, voltage tolerances and AC specs differ - verify DC thresholds and timing margins before substitution.

What is the maximum capacitive load the SN74HC541PWG4 can drive reliably?

The SN74HC541PWG4 is characterized up to 150 pF load capacitance. At CL = 150 pF and VCC = 6 V, typical propagation delay is 14 ns and output transition time (tt) is 13 ns. For reliable operation beyond 150 pF, add series termination or reduce slew rate via external RC networks - excessive capacitance increases delay, power dissipation, and risk of ringing.

How should unused inputs be handled on the SN74HC541PWG4?

All unused A inputs on the SN74HC541PWG4 must be terminated to a valid logic level - either VCC or GND - to prevent floating states that cause increased ICC, oscillation, or ESD susceptibility. TI recommends tying unused inputs directly (not through resistors) to minimize leakage-induced threshold uncertainty. OE1 and OE2 must also be actively driven or pulled low to ensure predictable 3-state behavior during power-up.