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Texas Instruments CD74AC251M96G4
- Part No.:
- CD74AC251M96G4
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
CD74AC251M96G4.pdf
- Description:
- IC MULTIPLEXER 1 X 8:1 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,703
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Product details
Overview
CD74AC251M96G4 from Texas Instruments is an 8-input CMOS multiplexer with true (Y) and complement (Y̅) outputs, three-state output enable (OE), 1.5V–5.5V supply operation, ±24mA drive capability, and 6ns typical propagation delay at 5V/25°C/50pF. It routes one of eight data inputs to dual outputs under 3-bit address control in industrial control logic, data acquisition systems, and digital signal routing.
For engineers reviewing the CD74AC251M96G4 datasheet, CD74AC251M96G4 pinout, CD74AC251M96G4 application, or CD74AC251M96G4 equivalent, key selection criteria include its wide VCC range (1.5–5.5V), balanced noise immunity at 30% of supply, SCR-latchup resistance, ESD tolerance (>2kV per MIL-STD-883), and SOIC-16 package compatibility with legacy 74AC logic families.
Technical Context
This device implements a single 8:1 multiplexer with complementary outputs and active-low three-state output enable. Its Harris Advanced CMOS process ensures latch-up immunity and stable operation across -55°C to +125°C, supporting both TTL- and CMOS-level input thresholds depending on VCC.
Propagation delays are balanced between data-to-output (min 3.4ns typ at 5V) and select-to-output paths, and switching characteristics are specified for CL = 50pF with input rise/fall times ≤3ns. The device supports fanout to 15 FAST™ ICs and direct 50Ω transmission-line driving at 85°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 1.5V to 5.5V - Enables interoperability with mixed-voltage systems including 1.8V, 3.3V, and 5V logic domains. |
| Propagation Delay (tPLH/tPHL) | 3.5ns typ (5V, 25°C, CL=50pF) - Supports high-speed data routing in real-time digital control loops. |
| Output Drive | ±24mA - Sufficient to directly drive 50Ω transmission lines or interface with multiple FAST™ loads without buffers. |
| Input Thresholds | VIH = 3.85V min, VIL = 1.65V max at VCC = 5.5V - Ensures robust noise margins and reliable TTL/CMOS level translation. |
| Three-State Leakage | ±5μA max (–55°C to +125°C) - Minimizes bus contention current when outputs are disabled in shared-bus architectures. |
| ESD Rating | >2kV HBM - Meets MIL-STD-883 Method 3015, reducing risk of field failure in handling and assembly. |
| Operating Temp | –55°C to +125°C - Qualified for extended-temperature industrial, automotive under-hood, and aerospace applications. |
Pinout & Package
CD74AC251M96G4 is housed in a 16-pin SOIC (D) package measuring 9.9mm × 6mm (body: 9.9mm × 3.9mm), RoHS-compliant with NIPDAU lead finish and MSL Level-1 rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| I0–I7 | Data Inputs | Eight independent digital inputs routed selectively to Y/Y̅; all have 10pF input capacitance and ±0.1μA leakage. |
| S0–S2 | Address Select Inputs | 3-bit binary select bus determining which Ix drives Y/Y̅; each has unit-load drive requirement. |
| Y / Y̅ | True & Complement Outputs | Dual buffered outputs active only when OE = LOW; both enter high-Z state simultaneously when OE = HIGH. |
| OE | Active-Low Output Enable | Asynchronous enable control: HIGH forces Y/Y̅ into high-impedance; no internal pull-up/down. |
| VCC / GND | Power Supply Pins | Single-supply operation; requires local 0.1μF bypass capacitor per VCC pin for stable high-speed switching. |
Key Features
| Feature | Design Value |
|---|---|
| Wide-Voltage Operation | 1.5V–5.5V supply range enables drop-in replacement in legacy 5V systems and migration to 1.8V/3.3V domains without redesign. |
| Balanced Propagation Delays | Matched tPLH/tPHL across all data and select paths minimizes skew in time-critical sampling and address decoding. |
| SCR-Latchup Resistant Process | Harris Advanced CMOS fabrication prevents destructive latch-up under transient overvoltage or ESD events. |
| Buffered Inputs | Internal input buffers isolate upstream drivers from capacitive loading, maintaining signal integrity across fanout chains. |
| Transmission-Line Drive | ±24mA output strength meets 50Ω line-drive requirement at 85°C, eliminating need for external line drivers in serial bus interfaces. |
Applications
| Industrial PLC I/O Multiplexing | Digital Test Equipment Signal Routing |
|---|---|
Use Scenario: Consolidating 8 analog sensor channels into a single ADC input via digital control. IC Role / Device Role / Timing Role: Data selector routing one of eight conditioned sensor signals to a shared A/D converter based on microcontroller address bits. Use Value: Reduces PCB component count and interconnect complexity while maintaining sub-10ns timing resolution for synchronized sampling. | Use Scenario: Switching stimulus signals between DUT pins during automated functional testing. IC Role / Device Role / Timing Role: High-speed signal path selector enabling programmable test vector application across multiple DUT inputs. Use Value: Achieves <15ns worst-case propagation delay at 5V, ensuring precise timing alignment between pattern generator and DUT response capture. |
| Legacy System Bus Expansion | Embedded Microcontroller Peripheral Sharing |
Use Scenario: Adding extra GPIO or interrupt lines to an aging 8-bit microcontroller with limited I/O. IC Role / Device Role / Timing Role: Address-decoded peripheral selector presenting up to eight external devices as memory-mapped registers. Use Value: Leverages existing address/data bus without requiring glue logic or FPGA, preserving system timing budget. | Use Scenario: Sharing a single UART or SPI interface among multiple sensors or actuators in a resource-constrained MCU design. IC Role / Device Role / Timing Role: Bidirectional data path controller enabling time-shared access to a common serial interface using OE-gated Y/Y̅ outputs. Use Value: Eliminates need for discrete analog switches or additional UART peripherals while maintaining full-duplex capability via complement output routing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 8-input multiplexer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74AC251N | Dual in-line package (PDIP-16); identical AC electrical specs but higher thermal resistance (RθJA = 140°C/W vs. 119.9°C/W). | Preferred for prototyping or through-hole assembly; less suitable for high-density or thermally constrained PCBs. | Select SN74AC251N only when manual soldering or breadboard evaluation is required. |
| CD74HC251E | High-speed CMOS variant with narrower VCC range (2V–6V), slower propagation (19ns typ at 5V), and lower drive (±5.2mA). | Acceptable for low-speed, low-power applications where 50Ω line drive or fast timing is not required. | Choose CD74HC251E only when power budget is critical and timing slack exceeds 15ns. |
Compared with SN74AC251N and CD74HC251E, CD74AC251M96G4 delivers superior thermal performance in surface-mount layouts, higher drive strength for transmission-line interfacing, and tighter propagation delay consistency-making it optimal for industrial automation and test equipment demanding deterministic timing and long-term reliability.
Availability
CD74AC251M96G4 is available at Aetrix Electronics and suitable for industrial control systems, automated test equipment, legacy system upgrades, and embedded peripheral expansion requiring stable component supply and extended temperature support.
Supply support for CD74AC251M96G4 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 for industrial, automotive, and consumer applications.
The CD74AC251M96G4 belongs to TI's Advanced CMOS Logic family, designed specifically for high-speed, low-power digital signal routing in harsh-environment systems requiring latch-up immunity and wide supply voltage flexibility.
FAQ
What is the maximum operating temperature for CD74AC251M96G4?
The CD74AC251M96G4 is rated for continuous operation from –55°C to +125°C ambient temperature, validated per TI's recommended operating conditions and thermal metrics (RθJA = 119.9°C/W). This specification applies to the SOIC-16 package under standard PCB mounting conditions with adequate copper pour and airflow. Derating is not required within this range, and the device maintains full electrical performance-including propagation delay and output drive-across the entire span. CD74AC251M96G4 is commonly deployed in motor control cabinets and outdoor instrumentation where such extremes occur.
Does CD74AC251M96G4 support 3.3V logic levels?
Yes, CD74AC251M96G4 fully supports 3.3V operation: its VCC range includes 3.3V (within 1.5V–5.5V), input thresholds scale proportionally (VIH ≈ 2.1V min, VIL ≈ 0.9V max at VCC = 3V), and output drive remains ±24mA. At 3.3V, typical propagation delay is 4.7ns (CL = 50pF), and noise immunity is maintained at 30% of supply (≈1.0V). CD74AC251M96G4 interfaces seamlessly with 3.3V microcontrollers and FPGAs without level shifters, making it ideal for mixed-voltage board designs.
How does the Output Enable (OE) pin function on CD74AC251M96G4?
The OE pin on CD74AC251M96G4 is an active-low, asynchronous control that places both Y and Y̅ outputs into high-impedance (three-state) mode when driven HIGH, regardless of address or input states. When OE is LOW, the multiplexer operates normally-routing the selected Ix to Y and its inverse to Y̅. OE has no internal pull-up or pull-down, so external biasing is required in floating-control scenarios. CD74AC251M96G4 uses OE to enable bus sharing, allowing multiple devices to coexist on a common data path without contention.
Can CD74AC251M96G4 drive a 50Ω transmission line directly?
Yes, CD74AC251M96G4 can directly drive a 50Ω transmission line: its ±24mA output drive capability meets the 50Ω requirement at 85°C (verified per datasheet Section 4.4, footnote 2), and its 6ns typical propagation delay ensures minimal signal distortion. At 5V, the output swing reaches 4.4V (VOH) and 0.1V (VOL), providing sufficient margin for clean logic transitions over 10–20cm traces. CD74AC251M96G4 eliminates the need for external line drivers in applications like JTAG daisy-chains or sensor bus backplanes.
Is CD74AC251M96G4 pin-compatible with older 74LS251 or 74F251 devices?
No, CD74AC251M96G4 is not pin-compatible with 74LS251 or 74F251: although all are 16-pin 8:1 multiplexers with Y/Y̅ and OE, the pin assignments differ significantly-for example, CD74AC251M96G4 places S2 on pin 9, whereas 74LS251 places S2 on pin 10. Additionally, CD74AC251M96G4 uses SOIC packaging with different thermal and mechanical footprints. Direct replacement requires PCB layout revision. CD74AC251M96G4 is designed as a functional upgrade-not a drop-in substitute-for legacy bipolar logic in new designs.
CD74AC251M96G4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74AC
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Multiplexer
- Circuit:
- 1 x 8:1
- Independent Circuits:
- 1
- Current - Output High, Low:
- 75mA, 75mA
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- 1.5V ~ 5.5V
- Operating Temperature:
- -55°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
CD74AC251M96G4 FAQ
1.How can I place an order for CD74AC251M96G4 through Aetrix?
Please submit a Request for Quotation (RFQ) for CD74AC251M96G4 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 CD74AC251M96G4 reliable?
The price and inventory of CD74AC251M96G4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CD74AC251M96G4 is usually 5 days.
3.What payment methods are accepted for CD74AC251M96G4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CD74AC251M96G4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CD74AC251M96G4?
CD74AC251M96G4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CD74AC251M96G4 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 CD74AC251M96G4?
For technical support, including CD74AC251M96G4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CD74AC251M96G4 requirements.
6.How does Aetrix verify that CD74AC251M96G4 is sourced from the original manufacturer or authorized distributors?
All CD74AC251M96G4 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 CD74AC251M96G4 meets industry standards.
7.What is the process for return or replacement of CD74AC251M96G4?
All CD74AC251M96G4 units undergo pre-shipment inspection (PSI). If there is an issue with CD74AC251M96G4, 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 CD74AC251M96G4 part is unused and in its original packaging.
Return procedure for CD74AC251M96G4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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