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onsemi 74LCX543MTCX
- Part No.:
- 74LCX543MTCX
- Manufacturer:
- onsemi
- Package:
- 24-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
74LCX543MTCX.pdf
- Description:
- IC TXRX NON-INVERT 3.6V 24TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:5,000
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Product details
Overview
74LCX543MTCX from ON Semiconductor is a low-voltage octal registered transceiver with 5V-tolerant I/O, designed for bidirectional data flow between 2.5V/3.3V logic domains and 5V systems. It features dual 8-bit D-type latch sets, independent A-to-B and B-to-A control (CEAB/CEBA, LEAB/LEBA, OEAB/OEBA), ±24 mA drive at VCC = 3.0V, and 7.0 ns max propagation delay at 3.3V - enabling use in voltage-level-translating bus interfaces for industrial controllers and embedded communication subsystems.
For engineers reviewing the 74LCX543MTCX datasheet, pinout, applications, or equivalent options, key selection criteria include 5V-tolerant I/O compatibility, separate latch/output enable per direction, 24-pin TSSOP package constraints, and timing parameters such as tPZL ≤ 9.0 ns (VCC = 3.3V) for synchronous bus arbitration and hot-swap support.
Technical Context
The 74LCX543MTCX implements two independent 8-bit non-inverting registered transceiver paths: A-to-B and B-to-A, each with dedicated latch enable (LEAB/LEBA), output enable (OEAB/OEBA), and direction enable (CEAB/CEBA). Its CMOS-based architecture supports live insertion/withdrawal via power-down high-impedance I/O states and patented noise/EMI reduction circuitry.
It operates across 2.3V–3.6V VCC while maintaining full 0–5.5V input/output voltage tolerance, enabling seamless interfacing between legacy 5V peripherals and modern low-voltage microcontrollers or FPGAs without external level shifters. Latch transparency and storage modes are controlled by edge-triggered LE inputs, with output buffers enabled only when both CE and OE are asserted low.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 2.3V to 3.6V - supports dual-supply system integration with 2.5V and 3.3V logic families |
| Input/Output Voltage Tolerance | 0V to 5.5V - enables direct connection to 5V buses without external level translation |
| tPD Max | 7.0 ns at VCC = 3.3V - ensures sub-10 ns timing margin for 100 MHz synchronous bus operation |
| Output Drive | ±24 mA at VCC = 3.0V - drives standard TTL loads and multiple CMOS inputs under worst-case conditions |
| ICC Max | 10 µA - maintains ultra-low static power in battery-backed or always-on control modules |
| IOZ Leakage | ±5.0 µA - guarantees reliable high-impedance isolation during 3-STATE mode in mixed-voltage backplanes |
| Operating Temperature | −40°C to +85°C - qualified for industrial-grade deployment in motor drives and PLC I/O modules |
Pinout & Package
74LCX543MTCX is housed in a 24-lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153 compliant, 4.4 mm wide, with 0.65 mm lead pitch - optimized for high-density PCB layouts in space-constrained industrial and telecom equipment.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| OEAB | A-to-B Output Enable (Active LOW) | Disables B-side outputs to high-impedance when HIGH; required LOW with CEAB for active A→B data transfer |
| OEBA | B-to-A Output Enable (Active LOW) | Disables A-side outputs to high-impedance when HIGH; required LOW with CEBA for active B→A data transfer |
| CEAB | A-to-B Enable (Active LOW) | Enables A-input sampling and B-output driving path; must be LOW for LEAB to affect A latches |
| CEBA | B-to-A Enable (Active LOW) | Enables B-input sampling and A-output driving path; must be LOW for LEBA to affect B latches |
| LEAB | A-to-B Latch Enable (Active LOW) | When LOW, A inputs pass through to A latches; rising edge stores data for B outputs |
| LEBA | B-to-A Latch Enable (Active LOW) | When LOW, B inputs pass through to B latches; rising edge stores data for A outputs |
| A0–A7 | A-side I/O terminals | Function as inputs during A→B transfer, outputs during B→A transfer - 5V-tolerant bidirectional ports |
| B0–B7 | B-side I/O terminals | Function as inputs during B→A transfer, outputs during A→B transfer - 5V-tolerant bidirectional ports |
Key Features
| Feature | Design Value |
|---|---|
| 5V-tolerant I/O | Allows direct interface with 5V peripherals while powered from 2.5V/3.3V rails - eliminates discrete level shifters in mixed-voltage designs |
| Independent direction control | Dual CE/LE/OE sets enable simultaneous or asynchronous A↔B data flow - critical for full-duplex bus arbitration in protocol bridges |
| Live insertion support | Power-down high-impedance I/O and controlled startup sequencing prevent bus contention during hot-plug operations in modular backplanes |
| Low-noise switching | Patented EMI reduction circuitry limits ground bounce and crosstalk - meets Class B emissions requirements in compact enclosures |
| Latch-up immunity | Exceeds 500 mA - ensures robustness against transient overvoltage events in industrial environments with noisy power supplies |
Applications
| Industrial PLC Backplane Interface | Embedded Microcontroller Bus Bridge |
|---|---|
|
Use Scenario: Interfacing a 3.3V ARM Cortex-M7 MCU with legacy 5V I/O expansion modules on a DIN-rail mounted PLC backplane. IC Role / Device Role / Timing Role: Bidirectional registered transceiver providing voltage translation, data latching, and output enable control between CPU and peripheral slots. Use Value: Eliminates need for discrete level shifters and glue logic; ±24 mA drive ensures signal integrity across 20 cm backplane traces at 25 MHz. |
Use Scenario: Connecting a 2.5V FPGA configuration interface to a 5V EEPROM boot loader and 5V CAN transceiver in an automotive body control module. IC Role / Device Role / Timing Role: Octal registered buffer isolating FPGA I/O from 5V peripherals while synchronizing data transfers using LE-driven latch edges. Use Value: Enables single-chip voltage translation and timing control; 7.0 ns tPD supports 100 Mbps serial boot loading without added latency. |
| Hot-Swappable Module Adapter | Low-Power Sensor Hub Interface |
|
Use Scenario: Enabling safe hot-insertion of 5V sensor cards into a 3.3V main controller chassis with automatic I/O isolation during power ramp-up. IC Role / Device Role / Timing Role: Registered transceiver implementing controlled power-up sequence via OE pull-up and CE/LE coordination. Use Value: Prevents bus contention during card insertion; power-down high-Z state ensures zero current draw until VCC stabilizes. |
Use Scenario: Aggregating 8-channel analog sensor readings (via 5V ADCs) into a 3.3V microcontroller-based environmental monitoring node. IC Role / Device Role / Timing Role: Level-translating data register capturing parallel ADC outputs and presenting them synchronously to MCU GPIOs. Use Value: Reduces MCU firmware overhead via hardware latching; 10 µA ICC enables >10-year battery life in wireless sensor nodes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal registered transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 74ALVC16245DGG | 16-bit, dual-supply (1.65V–3.6V), no 5V tolerance - requires external clamping for 5V I/O | Higher channel count but lacks 5V-tolerant inputs - suitable only in fully 3.3V systems | Select when scaling to 16-bit buses and 5V interfacing is unnecessary; verify VIH/VIL thresholds match host logic |
| SN74LVC8T245PW | 8-bit, 3.3V-only supply, 5V-tolerant I/O, no internal latches - requires external clocking for registered behavior | Provides level translation only; external flip-flops needed for latch functionality | Choose when design already includes clock distribution infrastructure and minimal gate count is prioritized over integrated latching |
Compared with 74LCX543MTCX, the 74ALVC16245DGG offers double the width but sacrifices 5V tolerance and adds complexity in mixed-voltage routing, while the SN74LVC8T245PW reduces integration by offloading latching to external logic - making 74LCX543MTCX optimal for self-contained, low-latency, mixed-voltage registered bus bridging.
Availability
74LCX543MTCX is available at Aetrix Electronics and suitable for industrial PLC backplanes, embedded microcontroller bus bridges, and hot-swappable module adapters requiring stable component supply, long-term lifecycle assurance, and consistent parametric performance across temperature extremes.
Supply support for 74LCX543MTCX 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
ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient power management, analog, logic, and custom devices for automotive, industrial, cloud computing, and IoT applications.
The 74LCX543MTCX belongs to ON Semiconductor's legacy LCX logic family - engineered for low-voltage operation with 5V-tolerant I/O to simplify migration from 5V TTL systems to modern low-power architectures.
FAQ
What is the maximum operating frequency supported by the 74LCX543MTCX?
The 74LCX543MTCX does not specify a maximum clock frequency directly, but its 7.0 ns maximum propagation delay (tPD) at VCC = 3.3V implies reliable operation up to approximately 100 MHz for setup/hold-compliant synchronous bus systems. Actual achievable frequency depends on board layout, load capacitance, and control signal timing margins - validated in the 74LCX543MTCX AC Electrical Characteristics table under tPHL/tPLH conditions.
Does the 74LCX543MTCX require external pull-up resistors on OE pins?
Yes - to ensure high-impedance outputs during power-up or power-down, OEAB and OEBA should each be tied to VCC via a pull-up resistor, as specified in Note 1 of the 74LCX543MTCX datasheet. The minimum resistance value depends on the driver's current-sourcing capability; typical values range from 4.7 kΩ to 10 kΩ for standard CMOS drivers interfacing with the 74LCX543MTCX.
Can the 74LCX543MTCX operate with a 2.5V supply voltage?
Yes - the 74LCX543MTCX is fully specified for VCC = 2.5V ± 0.2V, with guaranteed AC timing (e.g., tPD ≤ 8.4 ns) and DC parameters (e.g., VOH ≥ 2.2V at IOL = −12 mA). This makes the 74LCX543MTCX suitable for 2.5V system domains while retaining full 5V I/O tolerance, unlike many competing transceivers limited to 3.3V-only operation.
How does the 74LCX543MTCX handle unused input pins?
Unused inputs on the 74LCX543MTCX - including CEAB, CEBA, LEAB, LEBA, OEAB, and OEBA - must be held either HIGH or LOW; floating inputs are prohibited per Note 4 in the 74LCX543MTCX datasheet. For predictable operation, tie unused control inputs to GND (for active-LOW functions) or VCC (for active-HIGH logic), ensuring deterministic latch and output enable states across temperature and voltage variations.
Is the 74LCX543MTCX pin-compatible with other packages in the same family?
No - the 74LCX543MTCX uses the MTC24 (24-lead TSSOP) package, which has different pad layout, thermal characteristics, and mechanical dimensions than the SOIC (M24B) and SSOP (MSA24) variants. While all share identical logic function and pin assignments, PCB layout is not interchangeable; the 74LCX543MTCX requires its specific footprint defined in JEDEC MO-153 for reliable reflow and mechanical stability.
74LCX543MTCX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- 74LCX
- Package/Case:
- 24-TSSOP (0.173", 4.40mm 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:
- 24mA, 24mA
- Voltage - Supply:
- 2V ~ 3.6V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-TSSOP
74LCX543MTCX FAQ
1.How can I place an order for 74LCX543MTCX through Aetrix?
Please submit a Request for Quotation (RFQ) for 74LCX543MTCX 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 74LCX543MTCX reliable?
The price and inventory of 74LCX543MTCX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74LCX543MTCX is usually 5 days.
3.What payment methods are accepted for 74LCX543MTCX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74LCX543MTCX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74LCX543MTCX?
74LCX543MTCX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74LCX543MTCX 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 74LCX543MTCX?
For technical support, including 74LCX543MTCX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74LCX543MTCX requirements.
6.How does Aetrix verify that 74LCX543MTCX is sourced from the original manufacturer or authorized distributors?
All 74LCX543MTCX 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 74LCX543MTCX meets industry standards.
7.What is the process for return or replacement of 74LCX543MTCX?
All 74LCX543MTCX units undergo pre-shipment inspection (PSI). If there is an issue with 74LCX543MTCX, 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 74LCX543MTCX part is unused and in its original packaging.
Return procedure for 74LCX543MTCX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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