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Texas Instruments CY74FCT2543ATQCT
- Part No.:
- CY74FCT2543ATQCT
- Manufacturer:
- Texas Instruments
- Package:
- 24-SSOP (0.154", 3.90mm Width)
- Datasheet:
-
CY74FCT2543ATQCT.pdf
- Description:
- IC TXRX NON-INVERT 5.25V 24SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,275
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Product details
Overview
CY74FCT2543ATQCT from Texas Instruments is an octal latched transceiver with independent A-to-B and B-to-A data paths, 3-state outputs, Ioff partial-power-down support, 25-Ω on-die series termination resistors, and 6.5 ns maximum propagation delay at 5 V. It operates across –40°C to +85°C and is used in bidirectional bus interfacing between TTL/CMOS systems requiring noise-suppressed signal integrity.
For engineers reviewing the CY74FCT2543ATQCT datasheet, CY74FCT2543ATQCT pinout, CY74FCT2543ATQCT application, or CY74FCT2543ATQCT equivalent, key selection criteria include latch-enable timing (2 ns setup/hold), 12 mA sink / 15 mA source drive strength, matched rise/fall times, and QSOP-24 package compatibility with legacy FCT logic families.
Technical Context
This device integrates two independent sets of eight D-type latches with separate LEAB/LEBA and OEAB/OEBA controls, enabling concurrent bidirectional data storage and flow direction management. Each path features edge-rate-controlled outputs and on-chip 25-Ω series resistors to suppress transmission-line reflections.
The CY74FCT2543ATQCT implements Ioff circuitry that disables outputs when VCC = 0 V, limiting backflow current to ±1 µA - critical for hot-swap and partial-power-down systems. Its TTL-compatible input thresholds (VIL = 0.8 V, VIH = 2.0 V) and CMOS-level VOH (3.3 V typ) ensure interoperability across mixed-voltage logic domains.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Propagation Delay (tPLH/tPHL) | Max 6.5 ns - enables reliable operation up to ~150 MHz bus clocking with margin. |
| Output Drive Strength | 12 mA sink / 15 mA source - sufficient to drive standard TTL loads and stubbed buses. |
| On-Die Series Termination | 25 Ω ±20% - reduces signal overshoot/ringing without external resistors. |
| Ioff Current (VCC = 0 V) | ±1 µA - prevents damaging back-current during power sequencing or hot insertion. |
| Supply Voltage Range | 4.75 V to 5.25 V - tight regulation required; not 3.3 V tolerant. |
| Input Thresholds | VIL = 0.8 V, VIH = 2.0 V - fully compatible with standard TTL input levels. |
| ESD Protection | HBM 2000 V, MM 200 V, CDM 1000 V - exceeds JEDEC JESD22 requirements. |
Pinout & Package
Package: SSOP-24 (DBQ), 0.154" body width, 0.025" pitch, RoHS-compliant NIPDAU finish, MSL Level-2-260°C-1 year.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 24 | LEBA, LEAB | Active-low latch-enable inputs controlling B-to-A and A-to-B storage mode transitions. |
| 2, 23 | OEBA, OEAB | Active-low output-enable inputs disabling B-to-A or A-to-B 3-state buffers independently. |
| 3–10 | A0–A7 | A-side bidirectional I/O: inputs when CEAB low and OEAB low; high-Z outputs when OEAB high. |
| 11, 12 | CEAB, GND | Active-low A-to-B enable (controls data entry/storage path); ground reference pin. |
| 13, 14 | VCC, CEBA | +5 V supply; active-low B-to-A enable input. |
| 15–22 | B0–B7 | B-side bidirectional I/O: inputs when CEBA low and OEBA low; high-Z outputs when OEBA high. |
Key Features
| Feature | Design Value |
|---|---|
| Independent Dual-Path Latching | Separate LEAB/OEAB and LEBA/OEBA controls allow simultaneous A→B and B→A data capture and output. |
| Integrated Output Series Resistors | 25-Ω on-die resistors reduce PCB component count and improve signal integrity on unterminated traces. |
| Ioff Partial-Power-Down Support | Enables safe operation in systems where VCC may be unpowered while other rails remain active. |
| Matched Rise/Fall Times | Minimizes duty-cycle distortion and EMI in high-speed bidirectional data transfers. |
| TTL-Compatible Input/Output Levels | Accepts standard TTL inputs and drives TTL loads directly - no level-shifting circuitry required. |
Applications
| Backplane Bus Interface | Industrial PLC I/O Module |
|---|---|
|
Use Scenario: Bidirectional data exchange between CPU module and peripheral expansion slots in a modular control chassis. IC Role / Device Role / Timing Role: Latched transceiver managing time-critical address/data handshaking with independent A/B enable and latch control. Use Value: 6.5 ns max propagation delay ensures deterministic timing across 24-bit parallel buses; Ioff prevents backfeed during hot-swap of I/O cards. |
Use Scenario: Isolating and buffering field I/O signals (e.g., sensor inputs, relay outputs) from controller logic in harsh industrial environments. IC Role / Device Role / Timing Role: Noise-immune bidirectional interface with on-die termination and robust ESD protection (2000 V HBM). Use Value: 25-Ω series resistors suppress reflection-induced glitches on long PCB traces; 12 mA sink capability drives LED indicators and optocoupler inputs directly. |
| Legacy System Bus Extender | Test Equipment Data Capture |
|
Use Scenario: Interfacing modern microcontrollers to legacy 8-bit parallel buses (e.g., ISA, PC/104) with voltage and timing compatibility constraints. IC Role / Device Role / Timing Role: Level-translating latched transceiver supporting TTL input thresholds and 3.3 V typical VOH for mixed-voltage interoperation. Use Value: Eliminates need for discrete level shifters; functionally replaces CY74FCT543T with improved noise performance. |
Use Scenario: Capturing and forwarding high-fidelity digital stimulus/response waveforms in automated test equipment (ATE) channel interfaces. IC Role / Device Role / Timing Role: Low-skew, latch-synchronized data bridge between pattern generator and DUT interface boards. Use Value: Matched rise/fall times and 2 ns setup/hold guarantee clean sampling windows; 3-state outputs enable shared bus arbitration. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional latched transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY74FCT2543CTQCT | 5.5 ns max propagation delay (vs. 6.5 ns); identical pinout, package, and logic function. | Suitable for higher-speed timing-critical designs where <6 ns delay is mandatory. | Select when system timing budget requires tighter propagation margins; otherwise CY74FCT2543ATQCT offers better noise suppression via optimized edge rate. |
| SN74FCT2543ATPWR | Same speed grade (6.5 ns), but SOIC-24 package (DW) instead of QSOP-24 (DBQ); identical electrical specs. | Preferred for through-hole prototyping or legacy board layouts using SOIC footprints. | Choose for compatibility with existing SOIC-based PCBs; CY74FCT2543ATQCT is optimal for space-constrained surface-mount designs. |
Compared with CY74FCT2543CTQCT, the CY74FCT2543ATQCT trades 1 ns of speed for enhanced noise immunity via tuned edge-rate control; versus SN74FCT2543ATPWR, it delivers identical performance in a smaller QSOP footprint ideal for high-density routing.
Availability
CY74FCT2543ATQCT is available at Aetrix Electronics and suitable for industrial PLC I/O modules, backplane bus interfaces, legacy system extenders, test equipment data capture, and hot-swap-capable embedded controllers requiring stable component supply across extended temperature ranges.
Supply support for CY74FCT2543ATQCT 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 90 years of innovation in high-reliability industrial and automotive electronics.
The CY74FCT2543ATQCT belongs to TI's FCT logic family - designed specifically for noise-sensitive, high-speed bidirectional bus interfacing in industrial automation, communications infrastructure, and test instrumentation.
FAQ
What is the maximum operating frequency supported by the CY74FCT2543ATQCT?
The CY74FCT2543ATQCT does not specify a maximum clock frequency, but its 6.5 ns maximum propagation delay supports reliable operation on parallel buses with cycle times ≥13 ns - corresponding to effective data rates up to ~75 MHz in latch-controlled synchronous systems. Timing margins must account for setup/hold (2 ns each) and board trace delays.
Does the CY74FCT2543ATQCT support 3.3 V operation?
No, the CY74FCT2543ATQCT is a 5 V-only device with recommended VCC range of 4.75 V to 5.25 V. It is not 3.3 V tolerant: applying 3.3 V to VCC will result in undefined logic behavior and potential damage. For 3.3 V systems, consider TI's ALVC or LVC families instead.
How does the Ioff feature function in the CY74FCT2543ATQCT?
The Ioff feature in the CY74FCT2543ATQCT disables all outputs when VCC = 0 V, limiting reverse current flow to ±1 µA regardless of input/output voltage levels. This protects downstream circuitry during partial power-down, hot-swap events, or power sequencing mismatches - a critical requirement in modular industrial systems.
Can the CY74FCT2543ATQCT replace the CY74FCT543T in an existing design?
Yes, the CY74FCT2543ATQCT is functionally and pin-compatible with the CY74FCT543T and explicitly documented as a drop-in upgrade to reduce noise. It adds 25-Ω on-die series resistors and improved edge-rate control while maintaining identical logic behavior, timing, and package options - requiring no PCB changes.
What is the meaning of "FCT2543A" marking on the CY74FCT2543ATQCT package?
"FCT2543A" is the top-side marking for the CY74FCT2543ATQCT, indicating the FCT family, 2543 function (octal latched transceiver), and "A" speed grade (6.5 ns max propagation delay). This marking aligns with TI's standardized logic device nomenclature and appears on all production units in QSOP-24 packaging.
CY74FCT2543ATQCT 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
CY74FCT2543ATQCT FAQ
1.How can I place an order for CY74FCT2543ATQCT through Aetrix?
Please submit a Request for Quotation (RFQ) for CY74FCT2543ATQCT 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 CY74FCT2543ATQCT reliable?
The price and inventory of CY74FCT2543ATQCT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CY74FCT2543ATQCT is usually 5 days.
3.What payment methods are accepted for CY74FCT2543ATQCT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CY74FCT2543ATQCT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CY74FCT2543ATQCT?
CY74FCT2543ATQCT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CY74FCT2543ATQCT 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 CY74FCT2543ATQCT?
For technical support, including CY74FCT2543ATQCT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CY74FCT2543ATQCT requirements.
6.How does Aetrix verify that CY74FCT2543ATQCT is sourced from the original manufacturer or authorized distributors?
All CY74FCT2543ATQCT 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 CY74FCT2543ATQCT meets industry standards.
7.What is the process for return or replacement of CY74FCT2543ATQCT?
All CY74FCT2543ATQCT units undergo pre-shipment inspection (PSI). If there is an issue with CY74FCT2543ATQCT, 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 CY74FCT2543ATQCT part is unused and in its original packaging.
Return procedure for CY74FCT2543ATQCT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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