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Texas Instruments CD74FCT245ME4
- Part No.:
- CD74FCT245ME4
- Manufacturer:
- Texas Instruments
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
CD74FCT245ME4.pdf
- Description:
- IC TXRX NON-INVERT 5.25V 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:855
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Product details
Overview
CD74FCT245ME4 from Texas Instruments is a BiCMOS octal bus transceiver with 3-state outputs, designed for bidirectional data flow between two 8-bit buses in TTL-compatible systems. It features noninverted outputs, 64-mA sink capability per output, 3.7-V output voltage swing limitation to suppress EMI, and operation across 0°C to 70°C. Used in backplane interface and memory expansion circuits where bus isolation and controlled edge rates are critical.
For engineers reviewing the CD74FCT245ME4 datasheet, CD74FCT245ME4 pinout, CD74FCT245ME4 application, or CD74FCT245ME4 equivalent, key selection criteria include direction-control logic behavior, 3-state enable timing (ten = 1.5–9.5 ns), output current drive (IOL = 64 mA), and compatibility with 5-V TTL/CMOS mixed-signal environments.
Technical Context
The CD74FCT245ME4 implements a dual-bus transceiver architecture with separate DIR (direction) and OE (output enable) control inputs. Its BiCMOS output stage combines bipolar pull-down and CMOS pull-up devices to limit VOH to ~3.7 V at VCC = 5 V, reducing ground/VCC bounce during simultaneous switching.
Propagation delay tpd is 1.5–7 ns (A↔B), with enable/disable times ten and tdis specified from 1.5–9.5 ns and 1.5–7.5 ns respectively. Input thresholds meet TTL levels (VIH = 2 V, VIL = 0.8 V), and the device is SCR latch-up resistant per JEDEC JESD78.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.75 V to 5.25 V - Ensures stable operation within standard 5-V TTL power rails. |
| Output Sink Current | 64 mA per pin - Supports driving heavy capacitive loads or multiple TTL inputs without external buffers. |
| Propagation Delay | 1.5–7 ns - Enables high-speed bus handshaking in real-time control and data acquisition systems. |
| 3-State Enable Time | 1.5–9.5 ns - Determines minimum bus turnaround latency when switching data direction. |
| Input Thresholds | VIH = 2 V, VIL = 0.8 V - Guarantees interoperability with legacy TTL logic families without level shifting. |
| Output Voltage Swing | 0 V to 3.7 V - Reduces EMI and supply rail noise by limiting high-level output excursion below VCC. |
| Operating Temperature | 0°C to 70°C - Qualified for commercial-grade embedded systems including industrial HMIs and instrumentation. |
Pinout & Package
CD74FCT245ME4 is packaged in a 20-pin SOIC (DW) with 1.27-mm pitch, 7.5-mm body width, and 2.65-mm max height. Pin 1 is located at the top-left corner with notch or beveled edge marking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (DIR) | Direction Control Input | Low = B→A data flow; High = A→B data flow - defines real-time bus arbitration path. |
| 2–9 (A1–A8) | Bus A Data Inputs/Outputs | Bidirectional I/O pins connected to first 8-bit data bus; high-impedance when OE = High. |
| 10 (GND) | Ground Reference | Primary return path for all internal logic and output currents; must be low-inductance connection. |
| 11 (VCC) | Power Supply | +5-V supply input; decoupling capacitor required within 1 cm to suppress switching noise. |
| 12–19 (B1–B8) | Bus B Data Inputs/Outputs | Second 8-bit bidirectional bus port; electrically isolated from A-side when OE = High. |
| 20 (OE) | Output Enable Input | Active-Low control - drives all A/B outputs into high-impedance state when High; ties to VCC via pullup for power-up safety. |
Key Features
| Feature | Design Value |
|---|---|
| BiCMOS Output Architecture | Combines bipolar sink + CMOS source for 64-mA drive while limiting VOH to 3.7 V - reduces EMI and rail collapse. |
| Controlled Edge Rates | Internal slew-rate control minimizes overshoot/ringing on PCB traces up to 50 pF load - improves signal integrity. |
| Input/Output Isolation | VCC-independent input clamping and output disable ensure no feedthrough during power sequencing or brownout. |
| SCR Latch-Up Resistance | Qualified per JEDEC JESD78 Class II (>200 mA) - enables robust operation in noisy industrial environments. |
| Buffered Inputs | High fan-in tolerance (Ci = 10 pF) and noise immunity (VIL(D) = 0.8 V) prevent false triggering from crosstalk. |
Applications
| Memory Expansion Interface | Industrial Backplane Bus |
|---|---|
|
Use Scenario: Connecting microcontroller address/data bus to external SRAM or EPROM in embedded controllers. IC Role / Device Role / Timing Role: Bidirectional data transceiver enabling read/write cycles between CPU and memory banks with direction switching synchronized to WR/RD strobes. Use Value: 64-mA sink current drives memory chip inputs directly; 3.7-V VOH prevents overvoltage stress on older 5-V memory parts. |
Use Scenario: Interfacing modular I/O cards to central PLC backplane in factory automation racks. IC Role / Device Role / Timing Role: Isolating and translating data between card-local bus and shared backplane bus using DIR-controlled flow and OE-gated arbitration. Use Value: Controlled edge rates suppress EMI in densely packed chassis; 3-state isolation prevents bus contention during hot-swap events. |
| Legacy System Bus Bridge | TTL-to-CMOS Signal Translation |
|
Use Scenario: Linking obsolete 8-bit microprocessor bus (e.g., Z80) to modern FPGA-based peripheral controller. IC Role / Device Role / Timing Role: Level-shifting and direction-managed data conduit with timing compatible with 2–4 MHz Z80 bus cycles. Use Value: Propagation delay ≤7 ns meets Z80 WAIT timing constraints; TTL-compatible inputs eliminate need for external level shifters. |
Use Scenario: Driving multiple 74HC-series logic inputs from a single 74FCT245ME4 output in mixed-logic test fixtures. IC Role / Device Role / Timing Role: Fanout buffer with active 3-state control, allowing dynamic reconfiguration of signal routing paths. Use Value: 64-mA sink capability supports ≥10 HC loads; 3.7-V VOH stays within HC VIH(max) margin while avoiding overstress. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74F245N | Fused-bipolar process; higher ICC (120 mA typ), no VOH limiting - outputs swing full VCC. | Higher EMI risk in dense layouts; less suitable for noise-sensitive analog-adjacent digital sections. | Prefer when maximum noise margin is needed and board layout allows aggressive decoupling. |
| 74ACT245SCX | Advanced CMOS; 50-mA sink, 3.5-V VOH, faster tpd (1.2–5 ns), but lower latch-up immunity (JESD78 Class I). | Better speed/power trade-off for new designs; not recommended for high-noise industrial settings. | Select for high-frequency data links where EMI is controlled via shielding and layout, not device-level swing limiting. |
Compared with SN74F245N and 74ACT245SCX, the CD74FCT245ME4 uniquely balances EMI suppression (via 3.7-V VOH), industrial latch-up resilience, and TTL-compatible timing - making it optimal for legacy integration and noise-critical commercial systems where reliability trumps peak speed.
Availability
CD74FCT245ME4 is available at Aetrix Electronics and suitable for memory expansion interfaces, industrial backplane buses, legacy system bus bridges, and TTL-to-CMOS signal translation requiring stable component supply and long-term industrial availability.
Supply support for CD74FCT245ME4 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 connectivity solutions with emphasis on reliability, longevity, and industrial qualification.
The CD74FCT245ME4 belongs to TI's 74FCT logic family - engineered for 5-V mixed-signal systems requiring low-noise bus interfacing, EMI control, and compatibility with legacy TTL infrastructure.
FAQ
What is the function of the DIR pin on the CD74FCT245ME4?
The DIR (direction) pin on the CD74FCT245ME4 determines data flow direction between the A and B buses: when DIR is Low, data transfers from B to A; when DIR is High, data flows from A to B. This real-time control enables dynamic bus arbitration in systems like memory-mapped peripherals or multi-master backplanes. The CD74FCT245ME4 requires no external logic to manage bidirectional communication - DIR directly configures the internal signal path.
How does the CD74FCT245ME4 reduce electromagnetic interference (EMI)?
The CD74FCT245ME4 reduces EMI through its BiCMOS output stage, which limits VOH to approximately 3.7 V (two diode drops below VCC) instead of full-rail swing. This controlled output voltage swing minimizes power-bus ringing, VCC bounce, and ground bounce during simultaneous output switching - critical in high-density PCBs. The CD74FCT245ME4 achieves this without external components, making it ideal for noise-sensitive applications like industrial instrumentation.
What is the recommended power-up sequence for the CD74FCT245ME4?
To ensure high-impedance outputs during power-up, the OE (output enable) pin of the CD74FCT245ME4 must be held High until VCC stabilizes. TI recommends tying OE to VCC through a pullup resistor; the minimum value depends on the driver's sink capability but typically ranges from 4.7 kΩ to 10 kΩ. This prevents bus contention or unintended data leakage before system initialization completes. The CD74FCT245ME4 does not require special sequencing for DIR or other inputs.
Can the CD74FCT245ME4 drive 74HC-series logic inputs reliably?
Yes, the CD74FCT245ME4 can drive 74HC-series inputs reliably: its VOH of ≥2.4 V at –15 mA meets HC VIH(min) = 3.15 V only if VCC ≥ 4.5 V, but its 3.7-V swing stays safely within HC absolute max ratings (VI < VCC + 0.5 V). More critically, its 64-mA sink current supports fanout of ≥10 HC loads. For guaranteed VIH margin, use with VCC = 5.0 V and verify loading per application. The CD74FCT245ME4 is widely deployed in HC/FCT hybrid systems.
What package type does CD74FCT245ME4 use, and is it RoHS-compliant?
The CD74FCT245ME4 uses a 20-pin SOIC (DW) package with 1.27-mm lead pitch, 7.5-mm body width, and 2.65-mm max height. Per TI's packaging documentation, CD74FCT245ME4 is RoHS-compliant with NIPDAU lead finish and meets JEDEC moisture sensitivity Level-1 (unlimited floor life at ≤30°C/60% RH). The "E4" suffix denotes TI's standard green, lead-free, halogen-free packaging - fully compatible with standard reflow profiles.
CD74FCT245ME4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74FCT
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tube
- 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, 64mA
- Voltage - Supply:
- 4.75V ~ 5.25V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SOIC
CD74FCT245ME4 FAQ
1.How can I place an order for CD74FCT245ME4 through Aetrix?
Please submit a Request for Quotation (RFQ) for CD74FCT245ME4 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 CD74FCT245ME4 reliable?
The price and inventory of CD74FCT245ME4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CD74FCT245ME4 is usually 5 days.
3.What payment methods are accepted for CD74FCT245ME4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CD74FCT245ME4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CD74FCT245ME4?
CD74FCT245ME4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CD74FCT245ME4 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 CD74FCT245ME4?
For technical support, including CD74FCT245ME4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CD74FCT245ME4 requirements.
6.How does Aetrix verify that CD74FCT245ME4 is sourced from the original manufacturer or authorized distributors?
All CD74FCT245ME4 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 CD74FCT245ME4 meets industry standards.
7.What is the process for return or replacement of CD74FCT245ME4?
All CD74FCT245ME4 units undergo pre-shipment inspection (PSI). If there is an issue with CD74FCT245ME4, 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 CD74FCT245ME4 part is unused and in its original packaging.
Return procedure for CD74FCT245ME4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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