NXP Semiconductors 74LVT543DB,118

Overview

74LVT543DB,118 from Philips Semiconductors is a 3.3V octal latched transceiver with dual enable (3-State), integrating D-type latch and bus transceiver functions in one 24-pin SSOP device. It supports bidirectional data flow between Port A and Port B with independent latch and output control per direction, delivers ±64mA/–32mA drive capability, operates from –40°C to +85°C, and interfaces directly with 5V TTL systems. It is used in high-speed backplane and motherboard data routing where latch-stable bus isolation is required.

For engineers reviewing the 74LVT543DB,118 datasheet, 74LVT543DB,118 pinout, 74LVT543DB,118 application, or 74LVT543DB,118 equivalent, key selection criteria include dual-direction latch timing (tPLH/tPHL ≤ 5.8 ns), bus-hold input retention, power-up 3-State behavior, and compatibility with mixed-voltage 3.3V/5V board-level interconnects.

Technical Context

The 74LVT543DB,118 implements two independent 8-bit D-type latch banks - one for A→B and one for B→A data paths - each with dedicated Latch Enable (LEAB/LEBA), Enable (EAB/EBA), and Output Enable (OEAB/OEBA) inputs. All control inputs are active-Low and support asynchronous latch capture on Low-to-High transitions.

Its BiCMOS architecture enables 3.3V VCC operation while maintaining TTL-compatible input thresholds (VIL = 0.8V, VIH = 2.0V) and 5V-tolerant I/Os. Bus-hold circuitry on all A-side inputs eliminates external pull-ups, and power-up 3-State prevents bus contention during system initialization.

Key Specifications

Pinout & Package

74LVT543DB,118 is housed in a 24-pin plastic shrink small outline package (SSOP), body width 5.3 mm, drawing SOT340-1, with standard JEDEC lead pitch and moisture sensitivity level (MSL) appropriate for surface-mount reflow.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal latched transceiver applications.

Compared with 74LVT543DB,118, the 74ALVT16543DG,118 offers double data width but sacrifices bus-hold and pin compatibility, while the SN74LVC8T245RHLR omits 5V tolerance and latch enable precision - making 74LVT543DB,118 uniquely suited for mixed-voltage, latch-critical 8-bit routing.

Availability

74LVT543DB,118 is available at Aetrix Electronics and suitable for industrial PLCs, telecom line cards, test equipment interfaces, and backplane data routing requiring stable component supply, long-term lifecycle support, and verified 5V-tolerant operation.

Supply support for 74LVT543DB,118 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

Philips Semiconductors (now NXP Semiconductors) is a global semiconductor innovator founded in the Netherlands, known for high-reliability logic, analog, and interface solutions serving industrial and communications markets.

The 74LVT543DB,118 belongs to the LVT (Low-Voltage TTL) family, engineered for 3.3V systems requiring backward compatibility with 5V TTL signaling, high-speed bus isolation, and latch-controlled data staging in demanding embedded and infrastructure applications.

FAQ

What is the maximum operating temperature range for the 74LVT543DB,118?

The 74LVT543DB,118 is rated for continuous operation from –40°C to +85°C, meeting industrial temperature requirements. This range is validated across all electrical parameters including propagation delay, output drive, and bus-hold current, and applies specifically to the SSOP package variant (SOT340-1) used in the 74LVT543DB,118 ordering code.

Does the 74LVT543DB,118 support 5V logic inputs while powered at 3.3V?

Yes, the 74LVT543DB,118 supports 5V-tolerant inputs: VI can reach up to 5.5V while VCC = 3.3V, and it maintains valid TTL input thresholds (VIL ≤ 0.8V, VIH ≥ 2.0V). This allows direct interfacing with 5V systems without level shifters - a confirmed feature documented in the "Input voltage" and "DC electrical characteristics" sections of the Philips datasheet.

How does the bus-hold function work on the 74LVT543DB,118?

The 74LVT543DB,118 provides bus-hold circuitry exclusively on its A0–A7 inputs, delivering ±75 µA hold current at VCC = 3V to maintain the last-valid logic state when inputs float. This eliminates external pull-up resistors and is explicitly specified in the "DC electrical characteristics" table under IHOLD - no bus-hold is present on B-side pins.

Is the 74LVT543DB,118 pin-compatible with other 74LVT543 package variants?

No - the 74LVT543DB,118 uses the SSOP package (SOT340-1), which has different pad layout, lead pitch, and thermal characteristics than the SOL (SOT137-1) or TSSOP (SOT355-1) variants. While functional behavior and pin numbering match across packages, PCB footprint and soldering profiles are not interchangeable.

What happens to the outputs of the 74LVT543DB,118 during power-up?

During power-up, the 74LVT543DB,118 enters a defined 3-State (high-impedance) condition on all outputs - confirmed in the "Features" list and "FUNCTION TABLE" - preventing bus contention before system initialization completes. This behavior is intrinsic to the BiCMOS design and does not require external reset circuitry.