Texas Instruments SN74LS541NG4

Overview

SN74LS541NG4 from Texas Instruments is an octal buffer/line driver with 3-state outputs, designed for bidirectional data bus interfacing in TTL-based systems. It features non-inverting logic, ±24 mA output drive capability, 15 ns typical propagation delay (t_PLH/t_PHL), and operates over 0°C to 70°C. It is commonly used in microprocessor address/data bus isolation and memory I/O expansion.

For engineers reviewing the SN74LS541NG4 datasheet, SN74LS541NG4 pinout, SN74LS541NG4 application, or SN74LS541NG4 equivalent, this page delivers verified functional identity, confirmed PDIP-20 package mapping, validated 3-state control timing, exact DC electrical specs, and two rigorously cross-referenced alternative parts for legacy system redesign or obsolescence mitigation.

Technical Context

The SN74LS541NG4 implements eight independent non-inverting buffers, each with separate 3-state enable (OE̅) control via a common active-low output-enable input. Its TTL-compatible inputs accept standard LS logic thresholds (V_IL = 0.8 V max, V_IH = 2.0 V min), and outputs drive ±24 mA at V_OL ≤ 0.5 V and V_OH ≥ 2.7 V under rated load.

Propagation delay is specified at 15 ns (max 25 ns) across V_CC = 4.75–5.25 V and T_A = 25°C, with guaranteed fan-out of 20 LS-TTL loads. The device lacks internal clamping diodes and requires external transient suppression when interfacing with inductive loads or noisy buses.

Key Specifications

Pinout & Package

SN74LS541NG4 is supplied in a 20-pin plastic dual in-line package (PDIP-N), 0.300-inch body width, with standard through-hole mounting and JEDEC MS-001 compliant footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LS241N and SN74HC241N, SN74LS541NG4 provides unified 3-state control and LS-optimized drive/timing - making it the sole choice for maintaining timing-critical, high-fan-out TTL bus integrity in legacy upgrades.

Availability

SN74LS541NG4 is available at Aetrix Electronics and suitable for industrial control backplanes, legacy test equipment refurbishment, and microprocessor bus isolation requiring stable component supply and long-term lifecycle support.

Supply support for SN74LS541NG4 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 U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.

SN74LS541NG4 belongs to TI's legacy 74LS logic family, engineered specifically for robust, low-cost TTL bus interfacing in commercial-grade computing and control systems deployed from the 1980s onward.

FAQ

What is the function of SN74LS541NG4?

SN74LS541NG4 is an octal non-inverting 3-state buffer IC. It accepts eight TTL-compatible digital inputs and drives corresponding outputs only when the active-low output-enable (OE̅) pin is asserted LOW; otherwise, all outputs enter high-impedance state. This functionality enables safe bidirectional bus sharing in microprocessor and memory systems. SN74LS541NG4 maintains strict LS-TTL electrical characteristics including ±24 mA drive and 15 ns propagation delay.

Does SN74LS541NG4 support 3.3 V operation?

No, SN74LS541NG4 is strictly a 5 V TTL device with a required supply range of 4.75 V to 5.25 V. It does not operate reliably at 3.3 V - input thresholds and output voltage levels are undefined outside the 5 V domain, and internal circuitry is not designed for lower V_CC. For 3.3 V systems, consider CMOS alternatives like SN74LVC244A, but note that SN74LS541NG4 itself is incompatible with sub-4.75 V supplies.

What is the maximum capacitive load SN74LS541NG4 can drive?

SN74LS541NG4 is characterized to drive up to 20 LS-TTL loads, equivalent to approximately 400 pF of total capacitive load under standard conditions (V_CC = 5 V, T_A = 25°C). Exceeding this load increases propagation delay beyond the 25 ns maximum specification and may cause waveform rounding or setup/hold violations. For heavier loads, add series termination or reduce trace length - SN74LS541NG4 itself does not include slew-rate control.

Is SN74LS541NG4 RoHS compliant?

Yes, SN74LS541NG4 is RoHS compliant, as confirmed by Texas Instruments' official packaging documentation. It uses NiPdAu (NIPDAU) lead finish and meets EU Directive 2011/65/EU requirements. The "G4" suffix denotes green (halogen-free) packaging and RoHS-compliant construction, distinguishing it from earlier SNPB (lead-based) military variants like SNJ54LS541J.

Can SN74LS541NG4 replace SN74LS241N in a design?

SN74LS541NG4 cannot directly replace SN74LS241N without circuit modification because SN74LS241N has two independent 4-bit 3-state sections with separate OE̅ pins (1OE̅ and 2OE̅), whereas SN74LS541NG4 has a single OE̅ controlling all eight buffers. If the design relies on independent enable control, substitution will cause functional failure. However, if both OE̅ signals are tied together, SN74LS541NG4 may serve as a simplified replacement - but timing and loading must be re-verified. SN74LS541NG4 is not a pin-compatible drop-in for SN74LS241N.