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Texas Instruments CY74FCT2543CTQCT
- Part No.:
- CY74FCT2543CTQCT
- Manufacturer:
- Texas Instruments
- Package:
- 24-SSOP (0.154", 3.90mm Width)
- Datasheet:
-
CY74FCT2543CTQCT.pdf
- Description:
- IC TXRX NON-INVERT 5.25V 24SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,376
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Product details
Overview
CY74FCT2543CTQCT from Texas Instruments is an octal latched transceiver with 3-state outputs, designed for bidirectional data flow control between two 8-bit buses. It features independent A-to-B and B-to-A latch enable (LEAB/LEBA) and output enable (OEAB/OEBA) controls, 25-Ω on-chip series output resistors to suppress transmission-line reflections, Ioff support for partial-power-down operation, and TTL-compatible input/output logic levels. It operates at 5 V with 5.5 ns max propagation delay and is used in bus isolation and data buffering applications in industrial control systems.
For engineers reviewing the CY74FCT2543CTQCT datasheet, CY74FCT2543CTQCT pinout, CY74FCT2543CTQCT application, or CY74FCT2543CTQCT equivalent, key selection considerations include its dual-latch architecture, 3-state bidirectional drive capability, 12 mA sink / 15 mA source output strength, Ioff-enabled power-down safety, and QSOP-24 package compatibility with legacy FCT logic designs.
Technical Context
This device implements two independent sets of eight D-type latches - one for A-to-B and one for B-to-A data paths - each controlled by dedicated latch-enable and output-enable inputs. Its edge-rate control circuitry and integrated 25-Ω series resistors reduce switching noise and improve signal integrity across PCB traces.
The CY74FCT2543CTQCT supports full TTL-level compatibility (VIH = 2.0 V min, VIL = 0.8 V max), operates over –40°C to +85°C, and includes JESD22-compliant ESD protection (2000-V HBM). Its Ioff feature disables outputs when VCC = 0 V, preventing backflow current during partial power-down sequences.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.75 V to 5.25 V - ensures stable operation within standard 5 V ±5% industrial rail tolerance. |
| Propagation Delay (tPLH/tPHL) | 2.5 ns (min) to 5.5 ns (max) - enables high-speed bus interfacing up to ~180 MHz effective toggle rate. |
| Output Drive Strength | 12 mA sink / 15 mA source - sufficient to drive multiple TTL loads or moderate-capacitance PCB traces without external buffers. |
| Ioff Current | ±1 µA at VCC = 0 V - guarantees safe isolation during hot-swap or partial-power-down system states. |
| Input Hysteresis | 0.2 V - improves noise immunity on control lines (LEAB, OEAB, etc.) in electrically noisy environments. |
| On-Chip Series Resistance | 25 Ω (typical) - reduces overshoot/ringing on 50-Ω transmission lines without discrete termination components. |
| ESD Protection | 2000-V HBM, 200-V MM, 1000-V CDM - meets industrial-grade reliability requirements per JESD22. |
Pinout & Package
Package: SSOP-24 (DBQ), 0.154-inch body width, 0.635-mm lead pitch, RoHS-compliant NIPDAU finish, MSL Level-2-260°C-1 year.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | LEBA | B-to-A latch enable (active low); controls transparency/storage mode of B-to-A latches. |
| 2 | OEBA | B-to-A output enable (active low); activates/deactivates 3-state B outputs driving A bus. |
| 3–10 | A0–A7 | A-side data inputs (A→B path) or 3-state outputs (B→A path); bidirectional I/O terminals. |
| 11 | CEAB | A-to-B enable (active low); must be low to allow A→B data capture or B→A output enable. |
| 12 | GND | Ground reference for all internal circuitry and I/O signaling. |
| 13 | VCC | 5 V power supply input; powers internal logic and output drivers. |
| 14 | CEBA | B-to-A enable (active low); enables B→A data capture or A→B output enable. |
| 15–22 | B0–B7 | B-side data inputs (B→A path) or 3-state outputs (A→B path); bidirectional I/O terminals. |
| 23 | LEAB | A-to-B latch enable (active low); controls transparency/storage mode of A-to-B latches. |
| 24 | OEAB | A-to-B output enable (active low); activates/deactivates 3-state A outputs driving B bus. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent latch sets | Enables concurrent A↔B data staging without contention - critical for handshake-based bus arbitration. |
| Integrated 25-Ω series output resistors | Eliminates need for external series termination resistors, reducing BOM count and PCB area in high-speed interconnects. |
| Ioff partial-power-down support | Prevents damaging back-current when VCC is off while A/B buses remain live - essential for modular hot-plug systems. |
| TTL-compatible input thresholds | Accepts standard 0.8 V / 2.0 V logic levels without level-shifting, ensuring drop-in replacement for legacy 74LS/74F designs. |
| Matched rise/fall times | Minimizes duty-cycle distortion on clocked or strobed data paths, preserving timing margins in synchronous interfaces. |
Applications
| Industrial PLC Backplane Interface | Legacy Bus Isolation in Test Equipment |
|---|---|
Use Scenario: Isolating CPU and I/O module address/data buses in programmable logic controllers to prevent cross-talk and ground-loop interference. IC Role / Device Role / Timing Role: Bidirectional latched transceiver providing controlled, non-contentious data transfer between isolated 8-bit subsystems with independent direction control. Use Value: Eliminates bus contention during state transitions using separate LEAB/LEBA and OEAB/OEBA signals, enabling deterministic read/write sequencing. |
Use Scenario: Interfacing modern microcontroller-based test fixtures with vintage instrumentation using TTL-level parallel buses (e.g., GPIB auxiliary handshaking lines). IC Role / Device Role / Timing Role: Level-compatible buffer with 3-state outputs and latch storage, synchronizing asynchronous control signals across voltage-domain boundaries. Use Value: On-chip 25-Ω series resistors suppress reflections on long ribbon-cable runs, maintaining signal fidelity up to 100 MHz edge rates. |
| Automotive Body Control Module Data Hub | Medical Imaging Subsystem Data Mux |
Use Scenario: Aggregating sensor data from multiple CAN/LIN peripheral nodes into a central MCU via shared 8-bit parallel interface with power-gating capability. IC Role / Device Role / Timing Role: Partial-power-down enabled transceiver managing data flow between always-on sensor interfaces and intermittently powered processing cores. Use Value: Ioff functionality prevents reverse current injection during MCU sleep cycles, meeting ISO 16750-2 automotive power-supply transient requirements. |
Use Scenario: Routing time-critical image pixel data between FPGA-based acquisition logic and ADC/DAC modules in portable ultrasound systems. IC Role / Device Role / Timing Role: Low-skew, latch-controlled data path with matched rise/fall times preserving 8-bit parallel timing integrity across variable load conditions. Use Value: 5.5 ns max propagation delay and <2 ns skew ensure sub-10 ns setup/hold compliance for 100+ MSPS sampling clocks. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal latched transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY74FCT543CTQCT | No on-chip 25-Ω series resistors; higher output edge rates increase transmission-line ringing risk. | Suitable only where board-level termination is already implemented or trace lengths are very short (<2 cm). | Select only if noise margin is verified in target layout; CY74FCT2543CTQCT preferred for new designs requiring robust SI. |
| SN74FCT2543CTQCT | Same pinout and logic function but manufactured by TI under legacy FCT branding; identical electrical specs and thermal performance. | No functional difference - SN74FCT2543CTQCT is a direct second-source marking with identical qualification and lot traceability. | Valid alternative when CY74 prefix allocation is constrained; no design or qualification impact. |
Compared with CY74FCT543CTQCT, the CY74FCT2543CTQCT provides superior signal integrity via integrated termination, while SN74FCT2543CTQCT offers identical performance with alternate part-numbering - making the CY74FCT2543CTQCT the optimal choice for noise-sensitive, medium-length bus applications requiring guaranteed Ioff and ESD robustness.
Availability
CY74FCT2543CTQCT is available at Aetrix Electronics and suitable for industrial automation, test equipment, and automotive body electronics requiring stable component supply, long-term lifecycle support, and RoHS-compliant SSOP packaging.
Supply support for CY74FCT2543CTQCT 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 decades of experience in high-reliability industrial and automotive IC design.
The CY74FCT2543CTQCT belongs to TI's FCT logic family, engineered for noise-immune, TTL-compatible 5 V bus interfacing in mission-critical systems where signal integrity, power-down safety, and long-term manufacturability are mandatory.
FAQ
What is the maximum operating temperature range for the CY74FCT2543CTQCT?
The CY74FCT2543CTQCT is fully specified for operation from –40°C to +85°C ambient temperature. This range is validated across all electrical parameters including propagation delay, output drive, and Ioff leakage, making it suitable for industrial and under-hood automotive environments where thermal stability is critical. The SSOP-24 package's 61°C/W θJA ensures adequate thermal dissipation within this envelope.
Does the CY74FCT2543CTQCT support true bidirectional data flow without external logic?
Yes, the CY74FCT2543CTQCT supports fully independent bidirectional data flow using dedicated CEAB/CEBA, LEAB/LEBA, and OEAB/OEBA control inputs. Each direction operates autonomously - for example, A-to-B latching can occur while B-to-A outputs remain high-impedance - eliminating need for external direction-control logic or multiplexers in bus arbitration schemes.
How does the Ioff feature of the CY74FCT2543CTQCT protect downstream circuitry?
The Ioff feature in the CY74FCT2543CTQCT disables all outputs when VCC = 0 V, limiting current flow to ±1 µA even if A or B bus lines are driven externally. This prevents damaging back-current from live buses into a powered-down section - a key requirement for hot-swap capable systems and modular power architectures where subsystems power up/down asynchronously.
Can the CY74FCT2543CTQCT replace older 74F543 or 74LS543 devices in existing designs?
Yes, the CY74FCT2543CTQCT is functionally and pinout-compatible with 74F543 and 74LS543 devices, offering improved noise immunity, lower power consumption, and Ioff support. Its TTL-compatible input thresholds (VIH = 2.0 V min, VIL = 0.8 V max) and 5 V supply ensure seamless drop-in replacement - and the integrated 25-Ω series resistors often eliminate need for board-level termination upgrades.
What is the significance of the "C" suffix in CY74FCT2543CTQCT?
Within the CY74FCT2543x family, the "C" suffix denotes the 5.5 ns propagation delay grade (vs. "A" = 6.5 ns, standard "T" = 8.5 ns). The CY74FCT2543CTQCT delivers the fastest timing performance in the series, enabling reliable operation in high-speed 5 V bus systems where minimal latency and tight skew control are required - confirmed by its 2.5 ns min / 5.5 ns max tPLH/tPHL specification.
CY74FCT2543CTQCT 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:
- Active
- 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:
- 15mA, 12mA
- Voltage - Supply:
- 4.75V ~ 5.25V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-SSOP
CY74FCT2543CTQCT FAQ
1.How can I place an order for CY74FCT2543CTQCT through Aetrix?
Please submit a Request for Quotation (RFQ) for CY74FCT2543CTQCT 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 CY74FCT2543CTQCT reliable?
The price and inventory of CY74FCT2543CTQCT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CY74FCT2543CTQCT is usually 5 days.
3.What payment methods are accepted for CY74FCT2543CTQCT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CY74FCT2543CTQCT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CY74FCT2543CTQCT?
CY74FCT2543CTQCT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CY74FCT2543CTQCT 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 CY74FCT2543CTQCT?
For technical support, including CY74FCT2543CTQCT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CY74FCT2543CTQCT requirements.
6.How does Aetrix verify that CY74FCT2543CTQCT is sourced from the original manufacturer or authorized distributors?
All CY74FCT2543CTQCT 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 CY74FCT2543CTQCT meets industry standards.
7.What is the process for return or replacement of CY74FCT2543CTQCT?
All CY74FCT2543CTQCT units undergo pre-shipment inspection (PSI). If there is an issue with CY74FCT2543CTQCT, 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 CY74FCT2543CTQCT part is unused and in its original packaging.
Return procedure for CY74FCT2543CTQCT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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