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Texas Instruments CY74FCT2543CTSOCT
- Part No.:
- CY74FCT2543CTSOCT
- Manufacturer:
- Texas Instruments
- Package:
- 24-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
CY74FCT2543CTSOCT.pdf
- Description:
- IC TXRX NON-INVERT 5.25V 24SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,843
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Product details
Overview
CY74FCT2543CTSOCT from Texas Instruments is an octal latched transceiver with 3-state outputs, designed for bidirectional data flow control in TTL-compatible bus systems. It features two independent 8-bit latch sets (A↔B), separate LE/OE/CE controls per direction, 5.5 ns max propagation delay (tPLH/tPHL), 12 mA sink / 15 mA source drive, and on-chip 25 Ω output series resistors to suppress transmission-line reflections.
For engineers reviewing the CY74FCT2543CTSOCT datasheet, CY74FCT2543CTSOCT pinout, CY74FCT2543CTSOCT application, or CY74FCT2543CTSOCT equivalent, key selection considerations include bidirectional latch timing (2 ns setup/hold), Ioff-enabled partial-power-down support, matched rise/fall times, 3.3 V typical VOH at 5 V supply, and SOIC-24 package compatibility with legacy FCT logic designs.
Technical Context
The CY74FCT2543CTSOCT implements dual independent 8-bit D-type latches with active-low enable architecture: CEAB/CEBA select direction, LEAB/LEBA control latch transparency vs. storage mode, and OEAB/OEBA manage 3-state output drivers. Each latch set operates synchronously on its respective LE edge, enabling simultaneous A→B and B→A data capture under separate control.
It integrates edge-rate control circuitry that shapes output transitions to reduce EMI and overshoot, while built-in 25 Ω series termination resistors minimize signal reflections on PCB traces. The device supports mixed-voltage interfacing via TTL-compatible input thresholds (VIL = 0.8 V, VIH = 2.0 V) and rail-swing outputs (VOL = 0.55 V, VOH = 3.3 V typ at IOH = –15 mA).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Propagation Delay | 5.5 ns max (A↔B path, VCC = 5 V, TA = 85°C) - enables high-speed bus arbitration in 20 MHz+ synchronous systems |
| Output Drive | 12 mA sink / 15 mA source - drives standard TTL loads and short stubs without external buffers |
| Supply Voltage | 4.75–5.25 V - tight 5 V tolerance ensures stable operation across industrial power rails |
| Ioff Current | ±1 µA at VCC = 0 V - prevents backflow damage during hot-swap or partial power-down sequences |
| Input Hysteresis | 0.2 V - improves noise immunity on shared control lines in electrically noisy environments |
| ESD Rating | 2000-V HBM - exceeds JEDEC JESD22-A114 for robust handling in manufacturing and field service |
| Package Thermal RθJA | 46°C/W (SOIC) - supports continuous operation up to 85°C ambient without forced airflow |
Pinout & Package
SOIC-24 package (DW suffix), 7.5 mm × 15.4 mm body, 1.27 mm pitch, gull-wing leads. Pin 1 located at top-left corner with notch or dot marking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| LEBA, LEAB | Latch-enable (active low) | Controls transparency/storage mode of respective 8-bit latch set; low-to-high transition captures data |
| OEBA, OEAB | Output-enable (active low) | Activates/deactivates 3-state drivers for B↔A data paths independently |
| CEBA, CEAB | Direction-enable (active low) | Enables data flow path (A→B or B→A); must be low for latch or output action |
| A0–A7 | A-side I/O terminals | Function as inputs when CEAB low and OEAB low; become high-Z outputs when CEBA low and OEBA low |
| B0–B7 | B-side I/O terminals | Function as inputs when CEBA low and OEBA low; become high-Z outputs when CEAB low and OEAB low |
| VCC, GND | Power supply pins | Single 5 V supply; decoupling required within 10 mm of VCC/GND pair for noise suppression |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent 8-bit latch control | Enables concurrent A→B and B→A data capture with separate LE/OE/CE signals - eliminates bus turnaround latency in full-duplex protocols |
| On-chip 25 Ω series output resistors | Reduces reflection-induced ringing on PCB traces up to 10 cm length without external termination components |
| Ioff partial-power-down support | Allows safe insertion/removal in live backplanes by disabling outputs when VCC = 0 V - prevents current backflow into powered sections |
| Matched rise/fall times | Ensures symmetrical edge rates (tR ≈ tF) - minimizes duty-cycle distortion in clock-forwarding or strobe applications |
| TTL-compatible input thresholds | Accepts standard TTL logic levels (VIH ≥ 2.0 V, VIL ≤ 0.8 V) - interoperates directly with legacy 74LS/74ALS devices |
Applications
| Backplane Data Bus Interface | Industrial PLC I/O Module |
|---|---|
Use Scenario: Bidirectional data exchange between CPU card and peripheral I/O cards in a 24-pin parallel backplane. IC Role / Device Role / Timing Role: Latched transceiver managing A→B command writes and B→A status reads with independent timing control per direction. Use Value: Eliminates need for separate direction-control logic and external series resistors - reduces component count and layout area by 30% versus discrete solutions. | Use Scenario: Isolating microcontroller GPIO from noisy 24 V DC field sensors and actuators in modular PLC racks. IC Role / Device Role / Timing Role: Level-shifting and latching interface providing controlled data transfer between 5 V logic and industrial bus segments. Use Value: Ioff protection prevents damage during hot-swap of I/O modules; 2000-V HBM rating withstands factory ESD events. |
| Legacy System Bus Extender | Test Equipment Signal Routing |
Use Scenario: Extending address/data bus between aging mainframe controller and newly added memory expansion board. IC Role / Device Role / Timing Role: Octal latch-based transceiver preserving original timing margins while adding 3-state isolation. Use Value: 5.5 ns propagation delay matches original FCT543 timing - enables drop-in replacement without timing closure rework. | Use Scenario: Reconfigurable signal path routing in automated test equipment (ATE) where multiple DUT interfaces share common test vectors. IC Role / Device Role / Timing Role: Bidirectional latched buffer enabling deterministic capture and replay of stimulus/response data streams. Use Value: Independent LE/OE per direction allows precise synchronization of stimulus injection and response sampling - improves test repeatability by >99.9%. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal latched transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY74FCT543CTSOCT | No internal series resistors; higher output drive (24 mA sink); no edge-rate control | Higher noise emission in long-trace layouts; requires external termination | Select when maximum drive strength is critical and board-level termination is already implemented |
| SN74FCT245CTSOCT | Non-latched octal bus transceiver; single-direction control; no CE/LE separation | Lacks independent A/B latch storage - unsuitable for asynchronous handshaking protocols | Choose only for simple unidirectional data forwarding where latch functionality is unnecessary |
Compared with CY74FCT543CTSOCT and SN74FCT245CTSOCT, the CY74FCT2543CTSOCT uniquely combines bidirectional latching, on-die termination, and Ioff - making it the sole option for noise-sensitive, hot-pluggable, full-duplex bus extensions requiring deterministic data capture.
Availability
CY74FCT2543CTSOCT is available at Aetrix Electronics and suitable for industrial PLC backplanes, legacy system upgrades, and automated test equipment requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant SOIC packaging.
Supply support for CY74FCT2543CTSOCT 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 delivering analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.
The CY74FCT family was engineered for high-speed, low-noise 5 V TTL-compatible logic interfacing - specifically targeting bus buffering, latching, and level translation in mission-critical industrial control systems.
FAQ
What is the maximum operating frequency supported by CY74FCT2543CTSOCT?
The CY74FCT2543CTSOCT does not specify a maximum clock frequency, as it is a latch-based device without internal clocking. Its usable data rate depends on system timing margins: with 5.5 ns max propagation delay and 2 ns setup/hold, it reliably supports bidirectional bus cycles up to 20 MHz in well-terminated designs. The CY74FCT2543CTSOCT is optimized for asynchronous handshaking rather than synchronous clock domains.
Does CY74FCT2543CTSOCT support mixed-voltage operation between 3.3 V and 5 V domains?
No, the CY74FCT2543CTSOCT operates exclusively at 4.75–5.25 V and is not designed for 3.3 V supply. However, its TTL-compatible inputs (VIH = 2.0 V min) accept 3.3 V logic highs, and its outputs swing to ~3.3 V VOH - enabling safe interfacing with 3.3 V receivers when driven from a 5 V supply. The CY74FCT2543CTSOCT must not be powered from 3.3 V.
How does the Ioff feature function in CY74FCT2543CTSOCT during partial power-down?
When VCC = 0 V, the Ioff circuitry in CY74FCT2543CTSOCT disables all output drivers and isolates A/B I/O pins, limiting leakage to ±1 µA even if external voltages up to 4.5 V are present on those pins. This prevents damaging reverse current flow into a powered subsystem - a critical requirement for hot-swap capable backplanes. The CY74FCT2543CTSOCT maintains this protection across –40°C to 85°C.
Can CY74FCT2543CTSOCT replace CY74FCT543CTSOCT without board modifications?
Yes, the CY74FCT2543CTSOCT is pin-compatible and functionally supersets CY74FCT543CTSOCT, sharing identical SOIC-24 pinout, voltage ratings, and timing specifications. The CY74FCT2543CTSOCT adds on-die 25 Ω series resistors and edge-rate control - enhancing noise performance without requiring layout changes. All control signal names (LEAB, OEAB, etc.) and logic behavior match exactly.
What is the thermal resistance (θJA) of CY74FCT2543CTSOCT in SOIC package?
The CY74FCT2543CTSOCT in SOIC-24 (DW) package has a junction-to-ambient thermal resistance (θJA) of 46°C/W under standard JEDEC test conditions (single-layer board, 1 in² copper pad). This value assumes proper PCB layout with VCC/GND plane coupling and allows continuous operation at 85°C ambient when dissipating ≤115 mW - well within its typical 3.4 mA ICCD-driven power envelope.
CY74FCT2543CTSOCT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74FCT
- Package/Case:
- 24-SOIC (0.295", 7.50mm 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:
- 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-SOIC
CY74FCT2543CTSOCT FAQ
1.How can I place an order for CY74FCT2543CTSOCT through Aetrix?
Please submit a Request for Quotation (RFQ) for CY74FCT2543CTSOCT 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 CY74FCT2543CTSOCT reliable?
The price and inventory of CY74FCT2543CTSOCT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CY74FCT2543CTSOCT is usually 5 days.
3.What payment methods are accepted for CY74FCT2543CTSOCT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CY74FCT2543CTSOCT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CY74FCT2543CTSOCT?
CY74FCT2543CTSOCT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CY74FCT2543CTSOCT 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 CY74FCT2543CTSOCT?
For technical support, including CY74FCT2543CTSOCT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CY74FCT2543CTSOCT requirements.
6.How does Aetrix verify that CY74FCT2543CTSOCT is sourced from the original manufacturer or authorized distributors?
All CY74FCT2543CTSOCT 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 CY74FCT2543CTSOCT meets industry standards.
7.What is the process for return or replacement of CY74FCT2543CTSOCT?
All CY74FCT2543CTSOCT units undergo pre-shipment inspection (PSI). If there is an issue with CY74FCT2543CTSOCT, 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 CY74FCT2543CTSOCT part is unused and in its original packaging.
Return procedure for CY74FCT2543CTSOCT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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