Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

Home > Products > Integrated Circuits (ICs) > Logic > Buffers, Drivers, Receivers, Transceivers

onsemi 74ABT543CMSAX

Name: 74ABT543CMSAX
Brand: onsemi
SKU: 74ABT543CMSAX
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: 74ABT543CMSAX

Manufacturer:: onsemi

Category:: Buffers, Drivers, Receivers, Transceivers

Package:: 24-SSOP (0.209", 5.30mm Width)

Datasheet:: 74ABT543CMSAX.pdf

Description:: IC TXRX NON-INVERT 5.5V 24SSOP

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:3,056

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

74ABT543CMSAX from Fairchild Semiconductor is an octal registered transceiver with independent A↔B bidirectional data path control, dual D-type latch sets, 3-STATE outputs, and guaranteed output skew. It operates from 4.5V to 5.5V, supports 100 MHz toggle frequency, and delivers ±32 mA sourcing / 64 mA sinking drive strength on all I/O pins. It is used in high-speed bus interface applications requiring registered data flow control between subsystems.

For engineers reviewing the 74ABT543CMSAX datasheet, pinout, applications, or equivalent options, key selection considerations include latch enable/output enable independence per direction, simultaneous switching noise immunity, guaranteed skew under 2.0 ns (CL = 50 pF), hot-insertion capability, and compatibility with 50 pF and 250 pF load conditions.

Technical Context

The 74ABT543CMSAX implements two independent register banks - one for A→B and one for B→A data flow - each with dedicated Latch Enable (LEAB/LEBA), Output Enable (OEAB/OEBA), and Chip Enable (CEAB/CEBA) controls. This architecture enables asynchronous registration and 3-STATE buffering in both directions without contention.

It guarantees dynamic performance across temperature (−40°C to +85°C) and supply (4.5V–5.5V), including propagation delays ≤6.2 ns (tPLH/tPHL, CL = 50 pF), output disable time ≤8.5 ns, and pin-to-pin skew ≤2.0 ns for HL transitions - all verified under worst-case 8-output switching conditions.

Key Specifications

Parameter	Value and Actual Design Meaning
Supply Voltage	+4.5 V to +5.5 V - ensures compatibility with standard 5 V TTL/ABT logic systems and robust noise margin.
Max Toggle Frequency	100 MHz - supports high-speed synchronous bus transfers without timing violation under 50 pF load.
Output Drive Strength	32 mA sourcing / 64 mA sinking - drives heavy capacitive loads and multiple TTL inputs without external buffers.
Propagation Delay (tPLH/tPHL)	≤6.2 ns (CL = 50 pF) - enables sub-10 ns cycle timing in registered bus architectures.
Pin-to-Pin Skew (tOSHL)	≤2.0 ns - guarantees deterministic timing alignment across all 8 outputs for synchronous sampling.
Input Clamp Diode Voltage	−1.2 V - provides robust ESD protection and safe overvoltage tolerance during hot insertion.
Dynamic ICC	0.18 mA/MHz - enables predictable power estimation for high-frequency toggling in system-level power budgets.

Pinout & Package

74ABT543CMSAX is packaged in a 24-lead Shrink Small Outline Package (SSOP), EIAJ TYPE II, 5.3 mm wide (Package Number MSA24), with gull-wing leads and 0.65 mm pitch.

Pin/Terminal	Circuit Role	Design Meaning
A0–A7	Side A bidirectional I/O	Configurable as inputs (latched) or 3-STATE outputs; share same physical pins for A-side data path.
B0–B7	Side B bidirectional I/O	Configurable as inputs (latched) or 3-STATE outputs; share same physical pins for B-side data path.
LEAB, LEBA	Latch Enable (A→B, B→A)	Edge-triggered control: low-to-high transition captures data into respective latch bank.
OEAB, OEBA	Output Enable (A→B, B→A)	Active-low control of 3-STATE output drivers; independent of latch state for flexible bus arbitration.
CEAB, CEBA	Chip Enable (A→B, B→A)	Active-low gating of data flow path; disables latching and output driving when high.
VCC, GND	Power supply terminals	Single 5 V supply; decoupling required at package pins to meet simultaneous switching noise specs.

Key Features

Feature	Design Value
Bidirectional registered data path	Independent A→B and B→A latch+output control enables full-duplex buffered bus bridging without external logic.
Guaranteed output skew ≤2.0 ns	Ensures synchronized edge arrival across all 8 outputs - critical for reliable capture by downstream registers.
Hot-insertion capable	High-impedance glitch-free behavior during power-up/down prevents bus contention in live-backplane systems.
250 pF load support	Validated AC performance up to 250 pF confirms suitability for long traces, backplanes, or multi-drop routing.
Simultaneous switching noise immunity	Guaranteed noise level and dynamic threshold performance allow 8-bit concurrent toggling without false triggering.

Applications

PCI Bus Interface	Memory Subsystem Bridge
Use Scenario: Isolating and registering address/data signals between PCI controller and peripheral logic operating at different timing margins. IC Role / Device Role / Timing Role: Registered transceiver providing setup/hold time margin, bus contention prevention, and direction-controlled data staging. Use Value: Eliminates need for discrete latches and buffers while guaranteeing ≤6.2 ns propagation delay and ≤2.0 ns skew across all 8 lines.	Use Scenario: Interfacing a microprocessor's multiplexed address/data bus to separate SRAM or ROM address and data lines. IC Role / Device Role / Timing Role: Octal bidirectional latch and driver that de-multiplexes and registers bus signals with independent A/B enable control. Use Value: Supports 100 MHz toggle rate and 64 mA sink drive to directly drive memory address strobes and data lines without fanout buffers.
Industrial Backplane Interface	Digital Signal Processor (DSP) Data Path
Use Scenario: Connecting modular I/O cards to a central controller via a shared 8-bit parallel backplane with hot-swap capability. IC Role / Device Role / Timing Role: Registered transceiver enabling controlled data transfer, bus isolation during card insertion/removal, and noise-immune operation. Use Value: Nondestructive hot insertion and guaranteed simultaneous switching noise performance prevent system reset or data corruption during field maintenance.	Use Scenario: Buffering and synchronizing data between a DSP's external memory interface and a custom co-processor or ADC/DAC interface. IC Role / Device Role / Timing Role: Direction-controlled registered buffer that absorbs timing mismatches and provides clean, skew-controlled data handoff. Use Value: 32 mA source / 64 mA sink drive strength and ≤10.0 ns max delay (CL = 250 pF) ensure signal integrity across PCB interconnects to high-speed peripherals.

PCI Bus Interface

Memory Subsystem Bridge

Use Scenario: Isolating and registering address/data signals between PCI controller and peripheral logic operating at different timing margins.

IC Role / Device Role / Timing Role: Registered transceiver providing setup/hold time margin, bus contention prevention, and direction-controlled data staging.

Use Value: Eliminates need for discrete latches and buffers while guaranteeing ≤6.2 ns propagation delay and ≤2.0 ns skew across all 8 lines.

Use Scenario: Interfacing a microprocessor's multiplexed address/data bus to separate SRAM or ROM address and data lines.

IC Role / Device Role / Timing Role: Octal bidirectional latch and driver that de-multiplexes and registers bus signals with independent A/B enable control.

Use Value: Supports 100 MHz toggle rate and 64 mA sink drive to directly drive memory address strobes and data lines without fanout buffers.

Industrial Backplane Interface

Digital Signal Processor (DSP) Data Path

Use Scenario: Connecting modular I/O cards to a central controller via a shared 8-bit parallel backplane with hot-swap capability.

IC Role / Device Role / Timing Role: Registered transceiver enabling controlled data transfer, bus isolation during card insertion/removal, and noise-immune operation.

Use Value: Nondestructive hot insertion and guaranteed simultaneous switching noise performance prevent system reset or data corruption during field maintenance.

Use Scenario: Buffering and synchronizing data between a DSP's external memory interface and a custom co-processor or ADC/DAC interface.

IC Role / Device Role / Timing Role: Direction-controlled registered buffer that absorbs timing mismatches and provides clean, skew-controlled data handoff.

Use Value: 32 mA source / 64 mA sink drive strength and ≤10.0 ns max delay (CL = 250 pF) ensure signal integrity across PCB interconnects to high-speed peripherals.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
SN74ABT543DBR	TI SSOP-24 package; identical ABT logic family, same pinout, but slightly higher ICCZ (70 µA vs 50 µA) and no guaranteed 250 pF load spec.	Valid for 5 V bus interfaces where 250 pF loading is not required; lacks explicit hot-insertion validation.	Select when TI supply chain preference applies and 250 pF load support is unnecessary.
74F543SCX	Fairchild F-series variant: faster tPLH/tPHL (≤4.5 ns), but lower drive (20 mA/48 mA), no guaranteed skew, and no hot-insertion capability.	Suitable for speed-critical but low-load applications; not recommended for backplane or hot-swap use.	Select only if propagation delay is primary constraint and drive/skew/hot-swap are secondary.

Compared with SN74ABT543DBR and 74F543SCX, the 74ABT543CMSAX uniquely combines guaranteed 2.0 ns skew, 250 pF load validation, and nondestructive hot insertion - making it the preferred choice for industrial backplanes and PCI-adjacent registered bus designs where timing determinism and system robustness are mandatory.

Availability

74ABT543CMSAX is available at Aetrix Electronics and suitable for PCI bus interface, memory subsystem bridge, and industrial backplane interface applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for 74ABT543CMSAX 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

Fairchild Semiconductor was a U.S.-based analog and mixed-signal IC manufacturer, acquired by ON Semiconductor in 2016; its ABT logic family remains widely deployed in industrial and computing infrastructure.

The 74ABT543CMSAX belongs to Fairchild's Advanced BiCMOS Technology (ABT) logic series, designed specifically for high-speed, low-noise, registered bus interfacing in computing and communications equipment where timing precision and bus integrity are critical.

FAQ

What is the maximum load capacitance supported by the 74ABT543CMSAX?

The 74ABT543CMSAX is fully characterized and guaranteed for operation with 50 pF and 250 pF load capacitances. AC specifications including propagation delay (≤10.0 ns), skew (≤4.0 ns), and toggle frequency (100 MHz) are explicitly validated under 250 pF conditions per the datasheet's Extended AC Electrical Characteristics table - confirming suitability for long-trace or multi-drop bus implementations.

Does the 74ABT543CMSAX support hot insertion?

Yes, the 74ABT543CMSAX features nondestructive hot insertion capability. Its design ensures high-impedance glitch-free bus loading during the entire power-up and power-down cycle, preventing bus contention or signal corruption when inserted into a live system - a requirement explicitly stated in the General Description and validated through latchup protection and dynamic threshold testing.

What are the voltage thresholds for HIGH and LOW recognition on the 74ABT543CMSAX inputs?

The 74ABT543CMSAX recognizes input voltages ≥2.0 V as HIGH (VIH min) and ≤0.8 V as LOW (VIL max) across the full operating temperature range (−40°C to +85°C) and supply (4.5V–5.5V). These thresholds are guaranteed per DC Electrical Characteristics and provide 0.7 V noise margin at VCC = 5.0 V, ensuring reliable interfacing with standard TTL and CMOS logic families.

How does the 74ABT543CMSAX manage bidirectional data flow without bus contention?

The 74ABT543CMSAX avoids bus contention through independent, three-level control per direction: Chip Enable (CEAB/CEBA) gates data path entry, Latch Enable (LEAB/LEBA) controls registration timing, and Output Enable (OEAB/OEBA) separately activates 3-STATE drivers. This separation allows one direction to be latched and driven while the other remains high-impedance - confirmed by the Data I/O Control Table and functional description in the datasheet.

Is the 74ABT543CMSAX pin-compatible with other ABT-series transceivers like the 74ABT245?

No, the 74ABT543CMSAX is not pin-compatible with the 74ABT245. While both are octal transceivers, the 74ABT543CMSAX has 24 pins with dual latch/enable controls (LEAB/LEBA, OEAB/OEBA, CEAB/CEBA) and bidirectional I/O on A0–A7 and B0–B7, whereas the 74ABT245 uses 20 pins with single-direction control (DIR, OE) and separate input/output pins. Pin mapping, function allocation, and package footprint differ fundamentally.

74ABT543CMSAX Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: 74ABT

Package/Case:: 24-SSOP (0.209", 5.30mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Logic Type:: Transceiver, Non-Inverting

Number of Elements:: 1

Number of Bits per Element:: 8

Input Type:: -

Output Type:: 3-State

Current - Output High, Low:: 32mA, 64mA

Voltage - Supply:: 4.5V ~ 5.5V

Operating Temperature:: -40°C ~ 85°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 24-SSOP

74ABT543CMSAX FAQ

1.How can I place an order for 74ABT543CMSAX through Aetrix?

Please submit a Request for Quotation (RFQ) for 74ABT543CMSAX on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for 74ABT543CMSAX reliable?

The price and inventory of 74ABT543CMSAX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74ABT543CMSAX is usually 5 days.

3.What payment methods are accepted for 74ABT543CMSAX?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74ABT543CMSAX transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 74ABT543CMSAX?

74ABT543CMSAX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 74ABT543CMSAX order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for 74ABT543CMSAX?

For technical support, including 74ABT543CMSAX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74ABT543CMSAX requirements.

6.How does Aetrix verify that 74ABT543CMSAX is sourced from the original manufacturer or authorized distributors?

All 74ABT543CMSAX products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 74ABT543CMSAX meets industry standards.

7.What is the process for return or replacement of 74ABT543CMSAX?

All 74ABT543CMSAX units undergo pre-shipment inspection (PSI). If there is an issue with 74ABT543CMSAX, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The 74ABT543CMSAX part is unused and in its original packaging.

Return procedure for 74ABT543CMSAX:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

Tech Hub

2026-09-09 Counterfeit Electronic Components: How to Detect, Authenticate, and Test Suspect Parts

Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…