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Texas Instruments CY74FCT543CTQCTE4
- Part No.:
- CY74FCT543CTQCTE4
- Manufacturer:
- Texas Instruments
- Package:
- 24-SSOP (0.154", 3.90mm Width)
- Datasheet:
-
CY74FCT543CTQCTE4.pdf
- Description:
- IC TXRX NON-INVERT 5.25V 24SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,234
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Product details
Overview
CY74FCT543CTQCTE4 from Texas Instruments is an 8-bit latched registered transceiver with 3-state outputs, designed for bidirectional data flow control in TTL-compatible bus systems. It features independent A-to-B and B-to-A latch-enable (LEAB/LEBA) and output-enable (OEAB/OEBA) controls, 5.3 ns maximum propagation delay, 64 mA sink / 32 mA source drive strength, and Ioff support for partial-power-down operation in industrial backplane and memory interface applications.
For engineers reviewing the CY74FCT543CTQCTE4 datasheet, CY74FCT543CTQCTE4 pinout, CY74FCT543CTQCTE4 application, or CY74FCT543CTQCTE4 equivalent, key selection criteria include bidirectional latch timing (tsu = 2 ns, th = 2 ns), 3-state enable/disable times (tPZH/tPLZ ≤ 8 ns), VOH = 2.4 V min at IOH = –32 mA, VOL = 0.55 V max at IOL = 64 mA, and QSOP-24 package compatibility with legacy FCT logic families.
Technical Context
This device implements dual 8-bit D-type latches with separate CEAB/CEBA enable inputs and LEAB/LEBA latch-control inputs, enabling independent direction-selectable data registration. Each latch set drives complementary 3-state outputs with matched rise/fall times and edge-rate control circuitry to suppress switching noise.
It supports full TTL-level compatibility (VIH = 2 V min, VIL = 0.8 V max) and operates over –40°C to +85°C with VCC = 4.75–5.25 V. The Ioff feature disables outputs when VCC = 0 V, preventing backflow current during partial power-down-critical for hot-swap and mixed-voltage system designs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Propagation Delay (tPLH/tPHL) | 2.5–5.3 ns - Enables high-speed synchronous bus transfer with minimal skew between channels. |
| Output Drive Strength | 64 mA sink / 32 mA source - Drives heavy capacitive loads (e.g., 10+ TTL inputs) without external buffers. |
| Latch Setup/Hold Time | tsu = 2 ns, th = 2 ns - Supports tight-timing register-to-register transfers in pipelined architectures. |
| VCC Operating Range | 4.75–5.25 V - Matches regulated 5-V supply rails while rejecting ripple and noise within ±2.5% tolerance. |
| Ioff Current | ±1 µA at VCC = 0 V - Ensures safe isolation during power sequencing or standby modes without external isolation circuitry. |
| ESD Protection | 2000-V HBM, 200-V MM, 1000-V CDM - Meets industrial-grade robustness requirements without added protection components. |
| Input/Output Voltage Levels | VIH = 2 V, VIL = 0.8 V, VOH ≥ 2.4 V, VOL ≤ 0.55 V - Guarantees interoperability with standard TTL and earlier FCT logic families. |
Pinout & Package
Package: QSOP-24 (DBQ), 3.9 mm × 8.7 mm body, 0.635 mm pitch, RoHS-compliant NiPdAu lead finish, MSL Level-2-260°C-1 year.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| LEAB, LEBA | Latch-enable (active low) | Controls transparency/storage mode of respective A→B or B→A latches; low-to-high transition captures data. |
| OEAB, OEBA | Output-enable (active low) | Activates/deactivates 3-state outputs on corresponding port; high forces high-impedance state. |
| CEAB, CEBA | Direction-enable (active low) | Enables data path: CEAB low permits A→B flow; CEBA low permits B→A flow-mutually exclusive operation. |
| A0–A7 | Bidirectional I/O (A side) | When CEAB low and OEAB low: inputs to A latches; when CEBA low and OEBA high: 3-state outputs driven by B latches. |
| B0–B7 | Bidirectional I/O (B side) | When CEBA low and OEBA low: inputs to B latches; when CEAB low and OEAB high: 3-state outputs driven by A latches. |
| VCC, GND | Power supply terminals | Single 5-V supply; decoupling required within 1 cm due to fast edge rates and 5.6 mA dynamic current per 8-bit toggle. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent 8-bit latch paths | Enables concurrent A→B and B→A data registration with separate timing control-eliminates need for two discrete transceivers. |
| Edge-rate controlled outputs | Reduces simultaneous switching noise (SSN) by limiting dv/dt, easing EMC compliance in dense PCB layouts. |
| Matched rise/fall times | Minimizes duty-cycle distortion on clocked or strobed signals, preserving signal integrity in timing-critical interfaces. |
| TTL-compatible input thresholds | Accepts standard TTL VIH/VIL levels without level-shifting, simplifying integration into legacy 5-V systems. |
| Back-to-back latch architecture | Provides true registered transceiver behavior: data sampled on LEAB/LEBA edge, then gated to outputs via OEAB/OEBA-ideal for synchronous bus arbitration. |
Applications
| Industrial Backplane Interface | Memory Data Bus Isolation |
|---|---|
Use Scenario: Bidirectional data routing between CPU and peripheral modules across a shared 8-bit backplane with strict timing and noise constraints. IC Role / Device Role / Timing Role: Registered transceiver providing latch-controlled, direction-gated data transfer synchronized to system clock edges. Use Value: Eliminates bus contention via independent CEAB/CEBA enables and prevents metastability with 2 ns setup/hold margins. | Use Scenario: Isolating DRAM data lines from processor address/data bus during refresh cycles or DMA operations. IC Role / Device Role / Timing Role: Latched buffer holding valid data while upstream/downstream buses are reconfigured or powered down. Use Value: Ioff support ensures zero backfeed current when memory controller is unpowered, protecting DRAM I/O pins. |
| Legacy System Bus Expansion | Test Equipment Signal Conditioning |
Use Scenario: Adding new peripherals to aging 5-V microcontroller systems using FCT-family logic without redesigning voltage translation. IC Role / Device Role / Timing Role: Pin- and function-compatible upgrade to older 74F543 devices, retaining existing PCB layout and firmware timing. Use Value: 5.3 ns max propagation delay and TTL-compatible thresholds ensure drop-in replacement with no timing margin loss. | Use Scenario: Driving multiple test points from a single logic analyzer channel while maintaining signal fidelity and isolation. IC Role / Device Role / Timing Role: High-drive-strength 3-state buffer with controlled edge rates to minimize reflections on long probe traces. Use Value: 64 mA sink capability drives 50 Ω coaxial cables directly; edge-rate control reduces harmonic content above 100 MHz. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional latched transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74FCT543CTQCT | Same pinout, identical electrical specs, TI second-source part with identical marking "FCT543C". | No functional difference; used interchangeably in production where dual-sourcing is required. | Select when supply chain diversification or extended lifecycle assurance is prioritized over branding. |
| 74AC543SCX | Higher speed (tPD = 4.5 ns typ), lower drive (24 mA sink), no Ioff, AC logic family-not TTL-compatible. | Requires level-shifting for TTL interfaces; unsuitable for partial-power-down systems. | Choose only for new 3.3/5-V mixed designs where higher speed outweighs compatibility and power-down safety. |
Compared with SN74FCT543CTQCT, CY74FCT543CTQCTE4 offers identical performance and footprint but distinct TI internal traceability; versus 74AC543SCX, it provides guaranteed TTL interoperability and Ioff protection-making it the sole choice for industrial hot-swap and legacy bus extension.
Availability
CY74FCT543CTQCTE4 is available at Aetrix Electronics and suitable for industrial backplane interfaces, memory bus isolation, legacy system expansion, and test equipment signal conditioning requiring stable component supply across extended product lifecycles.
Supply support for CY74FCT543CTQCTE4 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 industrial, automotive, and communications markets.
CY74FCT543CTQCTE4 belongs to TI's FCT logic family-designed specifically for high-noise-immunity, TTL-compatible 5-V digital interfacing in mission-critical industrial and military-grade systems.
FAQ
What is the maximum operating temperature range for CY74FCT543CTQCTE4?
CY74FCT543CTQCTE4 is rated for operation from –40°C to +85°C ambient temperature. This industrial temperature grade ensures reliable performance in factory automation controllers, motor drives, and outdoor communication equipment where thermal cycling and extended runtime are common. The device maintains full electrical specifications-including 5.3 ns propagation delay and 64 mA output drive-across this entire range.
Does CY74FCT543CTQCTE4 support partial power-down, and how is it implemented?
Yes, CY74FCT543CTQCTE4 supports partial power-down via its Ioff circuitry. When VCC = 0 V, the outputs are actively disabled with leakage limited to ±1 µA-even if up to 4.5 V is applied to I/O pins. This prevents damaging reverse current flow during board-level power sequencing or hot-swap events. The feature is intrinsic to the silicon design and requires no external control signals or configuration.
Is CY74FCT543CTQCTE4 pin-compatible with older 74F543 devices?
CY74FCT543CTQCTE4 is functionally and pin-compatible with industry-standard 74F543 transceivers in the same QSOP-24 package. It retains identical pin assignments for LEAB, OEAB, CEAB, A0–A7, B0–B7, VCC, and GND. However, it improves upon the original with tighter timing (5.3 ns vs. 8.5 ns), higher drive strength, and Ioff-making it a direct drop-in replacement without PCB or firmware changes.
What are the recommended decoupling practices for CY74FCT543CTQCTE4?
TI recommends placing a 0.1 µF ceramic capacitor between VCC and GND within 1 cm of the CY74FCT543CTQCTE4 package, plus a bulk 4.7 µF tantalum or aluminum electrolytic capacitor near the power entry point. Due to its edge-rate controlled outputs and 5.6 mA dynamic current per full 8-bit toggle, localized high-frequency decoupling is essential to suppress ground bounce and maintain VOH/VOL stability under load.
Can CY74FCT543CTQCTE4 be used in systems with mixed 3.3-V and 5-V logic domains?
CY74FCT543CTQCTE4 operates exclusively at 5 V (4.75–5.25 V) and is not 3.3-V tolerant. Its inputs accept TTL-level signals (VIH = 2 V min), but applying 3.3-V logic directly to outputs risks violating VOH specifications and may cause marginal operation. For mixed-domain use, external level-shifting or a dedicated 5-V supply rail with proper isolation is required-TI does not specify or guarantee 3.3-V interface compatibility for CY74FCT543CTQCTE4.
CY74FCT543CTQCTE4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74FCT
- Package/Case:
- 24-SSOP (0.154", 3.90mm 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:
- 4.75V ~ 5.25V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-SSOP
CY74FCT543CTQCTE4 FAQ
1.How can I place an order for CY74FCT543CTQCTE4 through Aetrix?
Please submit a Request for Quotation (RFQ) for CY74FCT543CTQCTE4 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 CY74FCT543CTQCTE4 reliable?
The price and inventory of CY74FCT543CTQCTE4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CY74FCT543CTQCTE4 is usually 5 days.
3.What payment methods are accepted for CY74FCT543CTQCTE4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CY74FCT543CTQCTE4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CY74FCT543CTQCTE4?
CY74FCT543CTQCTE4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CY74FCT543CTQCTE4 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 CY74FCT543CTQCTE4?
For technical support, including CY74FCT543CTQCTE4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CY74FCT543CTQCTE4 requirements.
6.How does Aetrix verify that CY74FCT543CTQCTE4 is sourced from the original manufacturer or authorized distributors?
All CY74FCT543CTQCTE4 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 CY74FCT543CTQCTE4 meets industry standards.
7.What is the process for return or replacement of CY74FCT543CTQCTE4?
All CY74FCT543CTQCTE4 units undergo pre-shipment inspection (PSI). If there is an issue with CY74FCT543CTQCTE4, 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 CY74FCT543CTQCTE4 part is unused and in its original packaging.
Return procedure for CY74FCT543CTQCTE4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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