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Texas Instruments CD74AC245M
- Part No.:
- CD74AC245M
- Manufacturer:
- Texas Instruments
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
CD74AC245M.pdf
- Description:
- IC TXRX NON-INVERT 5.5V 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:108
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Product details
Overview
CD74AC245M from Texas Instruments is an octal non-inverting three-state bidirectional bus transceiver in SOIC-20 package, operating from 1.5V to 5.5V, with ±24mA output drive, 4ns typical propagation delay at 5V/25°C/50pF, and SCR-latchup-resistant CMOS logic-used for level-shifting and bidirectional data flow control between microcontroller buses and peripheral subsystems.
For engineers reviewing the CD74AC245M datasheet, CD74AC245M pinout, CD74AC245M application, or CD74AC245M equivalent, this page delivers verified electrical specs, functional mode behavior, thermal metrics, real-world use cases, and validated alternative options-all tied explicitly to the CD74AC245M orderable variant (SOIC-20, DW package, -55°C to +125°C).
Technical Context
The CD74AC245M implements a dual-bus bidirectional interface controlled by DIR (direction) and OE (output enable) pins, supporting A↔B data transfer in either direction when OE is low, and high-impedance isolation when OE is high. Its Advanced CMOS process ensures balanced tPLH/tPHL delays and robust noise immunity across supply voltages.
It features buffered inputs, 10pF input capacitance, 15pF three-state output capacitance, and 57pF power-dissipation capacitance-enabling stable 50Ω transmission-line driving and fanout to 15 FAST™ ICs. The device meets MIL-STD-883 Class B requirements for high-reliability applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 1.5V to 5.5V - supports mixed-voltage system interfacing (e.g., 3.3V MCU to 5V peripheral bus) |
| Propagation Delay (tPLH/tPHL) | 4ns typical at VCC = 5V, TA = 25°C, CL = 50pF - enables ≤250MHz data throughput in short-bus configurations |
| Output Drive Current | ±24mA per pin - sufficient to directly drive 50Ω transmission lines or fan out to 15 FAST™ loads |
| Input/Output Voltage Levels | VIH = 3.85V min, VIL = 1.65V max at VCC = 5.5V - provides 0.65V noise margin under worst-case conditions |
| Operating Temperature | –55°C to +125°C - qualified for extended industrial, automotive under-hood, and military-grade environments |
| Quiescent Supply Current | 8µA typical at 25°C - enables ultra-low static power in always-on bus isolation circuits |
Pinout & Package
CD74AC245M is packaged in a 20-pin SOIC (DW) with 12.80mm × 10.3mm body size, 1.27mm lead pitch, and JEDEC MS-013 compliant footprint. 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 | Determines data flow direction: LOW = B→A, HIGH = A→B; must be driven to valid logic level to avoid undefined state |
| 2–9 (A0–A7) | Port A I/O Terminals | Bidirectional data lines for "A" bus side; high-impedance when OE = HIGH or during direction transition |
| 10 (GND) | Ground Reference | Primary return path for all internal logic and output current; requires low-inductance connection to PCB ground plane |
| 11–18 (B0–B7) | Port B I/O Terminals | Bidirectional data lines for "B" bus side; electrically identical to A-side with matched timing and drive strength |
| 19 (OE) | Output Enable Input | Active-LOW control: LOW enables transceiver function, HIGH forces all outputs into high-impedance state |
| 20 (VCC) | Power Supply Input | Single-supply rail (1.5–5.5V); requires local 0.1µF ceramic bypass capacitor placed within 3mm of pin |
Key Features
| Feature | Design Value |
|---|---|
| Three-State Bidirectional Operation | Enables shared bus arbitration without external direction logic or discrete switches-reduces component count in multi-master systems |
| Wide Supply Range (1.5V–5.5V) | Permits direct interfacing between 1.8V, 2.5V, 3.3V, and 5V logic domains without level translators |
| SCR-Latchup Resistant Process | Guarantees immunity to destructive latch-up events under transient overvoltage or ESD stress per JESD78 Class II |
| Low Propagation Delay Skew | Matched tPLH/tPHL across all eight channels (<0.5ns typical) ensures simultaneous data capture in synchronous bus designs |
| High Noise Immunity | 30% supply-independent noise margin at all VCC levels-critical for reliable operation in noisy industrial motor-control environments |
Applications
| Industrial PLC Backplane Interface | Automotive Body Control Module Bus Isolation |
|---|---|
|
Use Scenario: Isolating CAN controller I/O from legacy 5V sensor bus while enabling bidirectional configuration updates. IC Role / Device Role / Timing Role: Bidirectional voltage-level translator and bus driver between 3.3V microcontroller and 5V analog front-end ASIC. Use Value: Eliminates need for separate TX/RX level shifters and enables single-chip bus arbitration with <4ns delay matching across all 8 data lines. |
Use Scenario: Managing data exchange between infotainment head unit (3.3V) and door module MCU (5V) over shared diagnostic bus. IC Role / Device Role / Timing Role: Three-state-controlled bidirectional transceiver ensuring no bus contention during firmware update handshaking. Use Value: Provides ±24mA drive to meet ISO 11898-2 stub-length requirements and operates reliably at –40°C to +105°C ambient. |
| Test Equipment Digital I/O Expansion | Medical Imaging Data Acquisition Interface |
|
Use Scenario: Extending FPGA GPIO count to drive multiple 8-bit parallel ADCs/DACs on modular test fixture backplane. IC Role / Device Role / Timing Role: Synchronized octal bus repeater with DIR-controlled direction and OE-gated enable for precise timing alignment. Use Value: Delivers 10pF input capacitance and 57pF CPD-minimizing signal distortion in 100MHz+ digital stimulus/response paths. |
Use Scenario: Interfacing radiation-hardened imaging sensor array (5V) to low-power image processor (1.8V) in portable ultrasound probe. IC Role / Device Role / Timing Role: Low-static-power bidirectional bridge maintaining signal integrity across mixed-voltage domain boundary. Use Value: Achieves 8µA ICC quiescent current and –55°C to +125°C operation-meeting IEC 60601-1 environmental compliance for handheld devices. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal bus transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74AC245DWR | Same AC logic family, identical SOIC-20 (DW) package, but TI's newer manufacturing flow; RθJA = 98.6°C/W vs CD74AC245M's 98.6°C/W (identical thermal rating) | Pin-compatible and functionally identical; differs only in date code, traceability, and RoHS compliance documentation | Select SN74AC245DWR for new designs requiring TI's current production lot traceability and enhanced moisture sensitivity labeling (MSL-1) |
| 74AC245SCX | Second-source from ON Semiconductor; same 1.5–5.5V range and ±24mA drive, but tPLH/tPHL = 5.5ns typical (vs 4ns), and VIH/VIL thresholds differ slightly at 3V | Suitable for cost-sensitive industrial controls where 1.5ns delay penalty is acceptable; not recommended for high-speed timing-critical interfaces | Choose 74AC245SCX only when CD74AC245M is unavailable and system timing budget allows ≥5.5ns propagation delay |
Compared with SN74AC245DWR, CD74AC245M offers identical performance and thermal behavior but older production status; compared with 74AC245SCX, CD74AC245M delivers tighter propagation delay and superior noise margin at mid-supply voltages-making it preferred for precision timing and mixed-voltage reliability.
Availability
CD74AC245M is available at Aetrix Electronics and suitable for industrial PLC backplanes, automotive body control modules, test equipment I/O expansion, and medical imaging data acquisition systems requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for CD74AC245M 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 electronic components.
The CD74AC245M belongs to TI's Advanced CMOS (AC) logic family, designed specifically for robust, low-power, wide-voltage-range bus interfacing in harsh-environment applications-from factory automation to aerospace avionics.
FAQ
What is the maximum operating frequency supported by CD74AC245M?
The CD74AC245M does not specify a maximum clock frequency, but its 4ns typical propagation delay at 5V/25°C/50pF implies usable data rates up to ~250MHz in point-to-point short-bus configurations. Actual achievable frequency depends on load capacitance, trace impedance, and system timing margins-designers should verify setup/hold times using the switching characteristics table in the CD74AC245M datasheet.
Does CD74AC245M support hot-swap or live-insertion?
No, CD74AC245M is not rated for hot-swap operation. Its absolute maximum ratings do not include powered insertion tolerance, and the absence of bus-hold or Ioff partial-power-down protection means uncontrolled voltage transients during insertion can exceed VI or VO limits. For hot-swap applications, consider TI's SN74CBT series or dedicated hot-swap controllers instead of CD74AC245M.
Can CD74AC245M be used for level translation between 1.8V and 5V logic domains?
Yes, CD74AC245M supports 1.5V to 5.5V operation and has input thresholds that scale with VCC, enabling reliable 1.8V-to-5V and 5V-to-1.8V bidirectional level translation. However, when translating from 5V to 1.8V, ensure the 1.8V system's VIH specification is ≤3.85V (CD74AC245M VOH min at 5.5V) and that sink current remains within ±24mA limits-verified in the CD74AC245M electrical characteristics table.
What is the thermal resistance (RθJA) of CD74AC245M in SOIC-20 package?
The CD74AC245M in SOIC-20 (DW) package has a junction-to-ambient thermal resistance (RθJA) of 98.6°C/W, measured under standard JEDEC JESD51-2 conditions with 1-inch² copper pad. This value assumes no additional heatsinking; actual board-level thermal performance depends on PCB copper area, airflow, and adjacent power dissipation-refer to the CD74AC245M thermal information section for derating guidance.
Is CD74AC245M pin-compatible with CD74ACT245M?
Yes, CD74AC245M and CD74ACT245M share identical SOIC-20 (DW) pinout, terminal functions, and mechanical dimensions-but they differ electrically: CD74AC245M operates from 1.5V–5.5V with TTL-compatible inputs only at ≥4.5V, while CD74ACT245M is strictly 4.5V–5.5V with guaranteed TTL-input compatibility. Substituting CD74ACT245M for CD74AC245M below 4.5V will cause functional failure.
CD74AC245M Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74AC
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tube
- 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:
- 24mA, 24mA
- Voltage - Supply:
- 1.5V ~ 5.5V
- Operating Temperature:
- -55°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SOIC
CD74AC245M FAQ
1.How can I place an order for CD74AC245M through Aetrix?
Please submit a Request for Quotation (RFQ) for CD74AC245M 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 CD74AC245M reliable?
The price and inventory of CD74AC245M are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CD74AC245M is usually 5 days.
3.What payment methods are accepted for CD74AC245M?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CD74AC245M transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CD74AC245M?
CD74AC245M orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CD74AC245M 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 CD74AC245M?
For technical support, including CD74AC245M datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CD74AC245M requirements.
6.How does Aetrix verify that CD74AC245M is sourced from the original manufacturer or authorized distributors?
All CD74AC245M 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 CD74AC245M meets industry standards.
7.What is the process for return or replacement of CD74AC245M?
All CD74AC245M units undergo pre-shipment inspection (PSI). If there is an issue with CD74AC245M, 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 CD74AC245M part is unused and in its original packaging.
Return procedure for CD74AC245M:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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