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Texas Instruments CD74AC244M
- Part No.:
- CD74AC244M
- Manufacturer:
- Texas Instruments
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
CD74AC244M.pdf
- Description:
- IC BUFF NON-INVERT 5.5V 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:248
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Product details
Overview
CD74AC244M from Texas Instruments is an octal 3-state non-inverting buffer/line driver in SOIC-20 package, operating from 1.5 V to 5.5 V, delivering ±24 mA output drive per channel, with balanced propagation delays (e.g., 7.5 ns max at 5 V), and designed for bus interface and data routing in industrial control systems.
For engineers reviewing the CD74AC244M datasheet, CD74AC244M pinout, CD74AC244M application, or CD74AC244M equivalent, this page delivers verified electrical specs, bank-specific 3-state control logic, thermal metrics for SOIC-DW packaging, and real-world implementation guidance for high-speed digital bus buffering.
Technical Context
The CD74AC244M implements two independent 4-bit banks (Bank 1: pins 2–9; Bank 2: pins 11–18), each with active-low output enable (1OE, 2OE), enabling selective bus isolation. Its RCA Advanced CMOS process ensures SCR-latch-up resistance and operation across −40°C to +85°C.
It features balanced noise immunity (30% of VCC), 50-Ω transmission-line drive capability, and low quiescent current (≤80 μA over temperature), supporting TTL- and CMOS-compatible interfacing without level-shifting in mixed-voltage systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 1.5 V to 5.5 V - Enables direct interface with 1.8 V, 3.3 V, and 5 V logic domains without external level shifters. |
| Output Drive Current | ±24 mA per output - Sufficient to fan out to 15 FAST ICs or directly drive 50 Ω PCB traces. |
| Propagation Delay (tPLH/tPHL) | ≤7.5 ns at VCC = 5 V - Supports >100 MHz bus toggle rates in point-to-point or lightly loaded stubbed topologies. |
| 3-State Leakage Current | ±5 μA max at +85°C - Ensures minimal bus contention during high-impedance state in multi-driver systems. |
| Input Thresholds (VIH/VIL) | VIH = 3.85 V, VIL = 1.65 V at 5 V - Provides 0.35 V noise margin for robust TTL-compatible input recognition. |
| Power Dissipation Capacitance | 71 pF typical - Used to calculate dynamic power: PD = VCC² × fIN × (CPD + CL), critical for thermal design at high frequencies. |
| Junction-to-Ambient RθJA | 101.2 °C/W (SOIC-DW) - Dictates maximum allowable power dissipation (e.g., ≤125 mW at 50°C ambient rise) for continuous operation. |
Pinout & Package
CD74AC244M uses a 20-pin SOIC (DW) package, 12.8 mm × 10.3 mm footprint, with gull-wing leads and exposed thermal pad (optional GND connection). Pin numbering follows standard dual-inline convention, with 1OE and 2OE controlling separate 4-bit banks.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1OE | Active-low enable for Bank 1 (pins 12–18 outputs) | Drives all four Bank 1 outputs to high-Z when logic HIGH; enables pass-through when LOW. |
| 1A0–1A3 | Inputs for Bank 1 | Non-inverting inputs mapped to outputs 1Y0–1Y3 (pins 18, 16, 14, 12). |
| 1Y0–1Y3 | Outputs for Bank 1 | Drive corresponding inputs with same logic level; high-Z when 1OE = HIGH. |
| 2OE | Active-low enable for Bank 2 (pins 3–9 outputs) | Independent control of Bank 2; allows asymmetric bus arbitration between two data groups. |
| 2A0–2A3 | Inputs for Bank 2 | Non-inverting inputs mapped to outputs 2Y0–2Y3 (pins 9, 7, 5, 3). |
| 2Y0–2Y3 | Outputs for Bank 2 | Match input states when 2OE = LOW; isolated otherwise - essential for bidirectional bus partitioning. |
| VCC (Pin 20) | Positive supply | Must be bypassed with 0.1 μF ceramic capacitor placed within 3 mm of pin to suppress switching noise. |
| GND (Pin 10) | Reference ground | Shared return path for both banks; connects to system ground plane to minimize ground bounce. |
Key Features
| Feature | Design Value |
|---|---|
| SCR-latch-up-resistant CMOS process | Guarantees immunity to destructive latch-up under transient overvoltage or ESD events per JEDEC JESD78. |
| Balanced propagation delays (tPLH ≈ tPHL) | Minimizes duty-cycle distortion in clock distribution or data strobe paths, critical for setup/hold timing closure. |
| 1.5 V to 5.5 V wide supply range | Eliminates need for voltage translators when interfacing legacy 5 V peripherals with modern 1.8 V/3.3 V microcontrollers. |
| ±24 mA output drive per pin | Supports direct termination of unterminated 50 Ω transmission lines without external drivers or resistors. |
| Low 3-state leakage (±5 μA @ +85°C) | Prevents unintended bus loading during sleep or standby modes, preserving signal integrity in multi-drop buses. |
Applications
| Industrial PLC I/O Expansion | Microcontroller Bus Isolation |
|---|---|
Use Scenario: Expanding GPIO count on a Cortex-M4-based PLC controller to drive 8-channel relay modules and analog input multiplexers. IC Role / Device Role / Timing Role: Non-inverting buffer isolating MCU GPIO from noisy industrial loads while maintaining signal polarity and timing alignment. Use Value: Enables clean separation of logic-level control signals from high-current actuator circuits, reducing ground loop interference and improving EMC performance. |
Use Scenario: Interfacing an ARM9 host processor with multiple peripheral ASICs sharing a common 8-bit data bus. IC Role / Device Role / Timing Role: 3-state bus driver providing controlled access to shared memory-mapped peripherals via independent bank enables (1OE/2OE). Use Value: Allows time-multiplexed bus arbitration without external logic, simplifying PCB layout and eliminating contention risk during read/write transitions. |
| Test Equipment Signal Routing | Legacy System Voltage Translation |
Use Scenario: Configurable signal path selection in automated test equipment where DUT interfaces require selectable 3.3 V or 5 V logic levels. IC Role / Device Role / Timing Role: Bidirectional buffer stage enabling programmable voltage-domain bridging between instrument FPGA and DUT connectors. Use Value: Delivers sub-10 ns propagation delay consistency across voltage rails, ensuring deterministic timing margins for high-speed pattern generation. |
Use Scenario: Upgrading a 5 V ISA-bus industrial PC to support newer 3.3 V PCIe add-in cards using passive backplane adapters. IC Role / Device Role / Timing Role: Level-shifting buffer translating 5 V control signals to 3.3 V-compatible enable and reset lines. Use Value: Maintains full logic compatibility without active translation ICs, reducing BOM cost and board space while meeting VIH/VIL thresholds of downstream 3.3 V devices. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal 3-state buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74AC244N | Same AC logic family, identical pinout and specs, but in PDIP-20 package (24.33 mm × 9.4 mm); higher RθJA (40 °C/W) limits power handling in compact enclosures. | Preferred for through-hole prototyping or legacy repair; unsuitable for high-density SMT layouts requiring SOIC footprint. | Select SN74AC244N only when manual assembly or socket-based testing is required; CD74AC244M offers superior thermal performance in reflow-soldered production. |
| CD74ACT244M96 | TTL-compatible input thresholds (VIH = 2.0 V, VIL = 0.8 V); slightly faster propagation (≤6.5 ns at 5 V) but narrower 4.5–5.5 V supply range. | Better suited for pure 5 V TTL systems; incompatible with 3.3 V or 1.8 V logic without level shifting. | Choose CD74ACT244M96 only in legacy 5 V-only designs where TTL input compatibility is mandatory; CD74AC244M provides broader voltage interoperability. |
Compared with SN74AC244N and CD74ACT244M96, CD74AC244M uniquely balances wide-supply operation (1.5–5.5 V), industrial temperature range (−40°C to +85°C), and SOIC-DW thermal efficiency-making it optimal for modern mixed-voltage embedded systems requiring long-term manufacturability and thermal headroom.
Availability
CD74AC244M is available at Aetrix Electronics and suitable for industrial automation, test equipment, and legacy system upgrades requiring stable component supply, extended temperature operation, and RoHS-compliant SOIC packaging.
Supply support for CD74AC244M 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 connectivity technologies, with over 90 years of innovation in high-reliability components.
CD74AC244M belongs to TI's legacy logic portfolio built on RCA Advanced CMOS technology, engineered for robust bus interfacing, noise immunity, and seamless integration into industrial and instrumentation systems.
FAQ
What is the maximum operating temperature range for CD74AC244M?
The CD74AC244M is rated for operation from −40°C to +85°C, matching the commercial-industrial temperature grade. This range is confirmed in Section 4.2 of the TI datasheet (SCHS287C) and applies specifically to the M-suffix SOIC package variant. It is not rated for extended military temperatures (−55°C to +125°C), which apply only to CD54-series ceramic packages.
Does CD74AC244M support 3.3 V logic systems without level shifters?
Yes, CD74AC244M fully supports 3.3 V operation: its 1.5 V to 5.5 V supply range includes 3.3 V nominal, and its input thresholds (VIH = 2.1 V min, VIL = 0.9 V max at 3.3 V) provide 0.4 V noise margin against standard 3.3 V CMOS outputs. No external level shifters are needed for interfacing with 3.3 V microcontrollers or FPGAs.
How are the two output-enable controls (1OE and 2OE) used in practice?
1OE and 2OE independently disable Bank 1 (outputs 1Y0–1Y3) and Bank 2 (outputs 2Y0–2Y3). In bus arbitration, one bank can remain active while the other is tri-stated-enabling time-multiplexed access to shared resources like memory or peripherals. Both must be LOW for full 8-bit operation; tying them together simplifies control but eliminates bank-level granularity.
Can CD74AC244M drive 50 Ω transmission lines directly?
Yes, CD74AC244M is explicitly characterized for 50 Ω transmission-line drive at +85°C (Section 4.4, footnote 2). With ±24 mA output current and ≤0.5 V VOL at 24 mA, it meets the voltage swing and edge rate requirements for point-to-point 50 Ω traces up to ~15 cm without external series termination.
Is CD74AC244M pin-compatible with CD74ACT244M96?
Yes, CD74AC244M and CD74ACT244M96 share identical SOIC-20 pinout, terminal functions, and package dimensions. However, they differ in input threshold compatibility (AC: 30% VCC noise margin; ACT: TTL thresholds) and supply range (AC: 1.5–5.5 V; ACT: 4.5–5.5 V), so direct substitution requires verification of voltage domain and logic family constraints.
CD74AC244M 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:
- Buffer, Non-Inverting
- Number of Elements:
- 2
- Number of Bits per Element:
- 4
- Input Type:
- -
- Output Type:
- 3-State
- Current - Output High, Low:
- 24mA, 24mA
- Voltage - Supply:
- 1.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SOIC
CD74AC244M FAQ
1.How can I place an order for CD74AC244M through Aetrix?
Please submit a Request for Quotation (RFQ) for CD74AC244M 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 CD74AC244M reliable?
The price and inventory of CD74AC244M are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CD74AC244M is usually 5 days.
3.What payment methods are accepted for CD74AC244M?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CD74AC244M transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CD74AC244M?
CD74AC244M orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CD74AC244M 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 CD74AC244M?
For technical support, including CD74AC244M datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CD74AC244M requirements.
6.How does Aetrix verify that CD74AC244M is sourced from the original manufacturer or authorized distributors?
All CD74AC244M 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 CD74AC244M meets industry standards.
7.What is the process for return or replacement of CD74AC244M?
All CD74AC244M units undergo pre-shipment inspection (PSI). If there is an issue with CD74AC244M, 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 CD74AC244M part is unused and in its original packaging.
Return procedure for CD74AC244M:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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