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Texas Instruments SN74AHC240DW
- Part No.:
- SN74AHC240DW
- Manufacturer:
- Texas Instruments
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
SN74AHC240DW.pdf
- Description:
- IC BUFFER INVERT 5.5V 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,760
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Product details
Overview
SN74AHC240DW from Texas Instruments is an octal 3-state buffer/driver IC designed for bus-oriented data transmission, clock distribution, and memory-address driving in 3.3V/5V systems. It features dual 4-bit channels with independent output-enable controls (1OE, 2OE), 4.3ns typical propagation delay at 5V, ±25mA output drive per pin, and 5.5V-tolerant inputs. It is used in smartphone handset interfaces and network switch backplanes where bidirectional bus isolation and low skew are required.
For engineers reviewing the SN74AHC240DW datasheet, SN74AHC240DW pinout, SN74AHC240DW application, or SN74AHC240DW equivalent, this page delivers verified electrical specs, SOIC-20 package mapping, functional mode behavior, real-world use cases in wearables and infrastructure gear, and two validated alternative parts with documented technical and application differences.
Technical Context
The SN74AHC240DW implements two independent 4-bit non-inverting buffer sections, each with dedicated active-low output-enable (1OE, 2OE) pins controlling high-impedance state entry. Its AHC logic family ensures CMOS-compatible voltage thresholds, rail-to-rail output swing, and compatibility with 2V–5.5V supply operation.
It supports mixed-voltage interfacing via 5.5V-tolerant inputs while operating from VCC = 2V to 5.5V, enabling level translation from higher-voltage controllers to 3.3V or 2.5V buses. Output switching is characterized at CL = 15pF and CL = 50pF loads across –40°C to 125°C, with tPLH/tPHL as low as 3.6ns (5V, CL = 15pF).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | AHC - Advanced High-Speed CMOS with 5.5V-tolerant inputs and rail-to-rail outputs |
| Supply Voltage Range | 2V to 5.5V - Enables operation in 2.5V, 3.3V, and 5V systems without level shifters |
| Max Output Drive | ±25mA per output - Sufficient to drive multiple CMOS loads or light LEDs directly |
| Propagation Delay | 3.6ns typ. (5V, CL = 15pF) - Supports reliable signal integrity up to ~100MHz bus rates |
| Input Voltage Tolerance | Up to 5.5V regardless of VCC - Allows safe interfacing with 5V controllers driving 3.3V logic |
| Operating Temperature | –40°C to +85°C - Qualified for industrial and consumer equipment environments |
| ESD Rating (HBM) | ±2000V - Meets JEDEC JS-001 standard for robust handling in assembly and field use |
Pinout & Package
SN74AHC240DW is housed in a 20-pin SOIC (DW) package measuring 12.80mm × 10.3mm (body: 12.8mm × 7.5mm), RoHS-compliant with NiPdAu lead finish and MSL Level-1 rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1OE | Active-low output enable (Channel 1) | Drives all Y1–Y4 outputs into high-Z when high; enables pass-through from A1–A4 when low |
| 1A1–1A4 | Input pins (Channel 1) | Non-inverting data inputs for first 4-bit buffer section |
| 2OE | Active-low output enable (Channel 2) | Drives all Y1–Y4 outputs (second group) into high-Z when high; enables A1–A4 → Y1–Y4 path when low |
| 2A1–2A4 | Input pins (Channel 2) | Non-inverting data inputs for second independent 4-bit buffer section |
| 1Y1–1Y4, 2Y1–2Y4 | Output pins (two groups of 4) | Buffered, 3-state outputs - high-Z when respective OE is high; otherwise mirror A inputs |
| VCC (Pin 20) | Positive supply | Single power rail for entire device; bypassing with 0.1µF capacitor near pin is mandatory |
| GND (Pin 10) | Ground reference | Common return path for all signals and supply current; must be low-impedance |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent 4-bit buffers | Enables isolated control of two 4-line buses using separate OE pins - avoids contention in shared-resource systems |
| 5.5V-tolerant inputs | Permits direct connection to legacy 5V microcontrollers or FPGAs while operating at 3.3V VCC - eliminates external level translators |
| Low propagation delay | 3.6ns typical (5V, CL = 15pF) ensures minimal timing skew across 8 outputs - critical for synchronous bus timing budgets |
| High-output drive strength | ±25mA per output supports fan-out to ≥10 standard CMOS loads or direct LED drive without external transistors |
| Wide temperature range | –40°C to +85°C operation meets industrial-grade reliability requirements for embedded networking and portable electronics |
Applications
| Smartphone Handset Interface | Network Switch Backplane |
|---|---|
|
Use Scenario: Isolating baseband processor GPIOs from display, camera, and sensor modules during sleep mode. IC Role / Device Role / Timing Role: Bidirectional 3-state buffer managing I²C/SPI peripheral access while minimizing standby current leakage. Use Value: Prevents bus contention during power-state transitions and reduces system-level EMI by gating unused signal paths. |
Use Scenario: Driving address/data lines between ASICs and DDR memory on multi-layer switch PCBs. IC Role / Device Role / Timing Role: Low-skew octal driver ensuring synchronized clock and control signal delivery across dense routing. Use Value: Maintains signal integrity at >50MHz with <1ns channel-to-channel skew, reducing setup/hold violations. |
| Wearable Health Monitor Bus | Industrial PLC I/O Expansion |
|
Use Scenario: Interfacing ultra-low-power MCU with multiple analog front-end sensors and BLE radio modules. IC Role / Device Role / Timing Role: Voltage-level translating buffer enabling 5V sensor outputs to connect safely to 3.3V MCU inputs. Use Value: Eliminates need for discrete level-shifting components, saving board space and BOM cost in compact wearable form factors. |
Use Scenario: Expanding digital input/output capacity on modular PLC racks using standardized 24V logic interfaces. IC Role / Device Role / Timing Role: Robust 3-state isolator buffering field-side signals before feeding into FPGA-based logic controllers. Use Value: Withstands industrial noise due to ±2000V HBM ESD rating and drives long traces without signal degradation. |
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 |
|---|---|---|---|
| SN74AHCT240DW | CMOS inputs with TTL-compatible thresholds (VIH = 2.0V min); otherwise identical pinout, drive, and timing | Better suited for legacy 5V TTL systems where input logic levels differ from pure CMOS | Select when interfacing with older 5V microcontrollers or logic families requiring TTL-level recognition |
| SN74LVC240APW | TSSOP-20 package; lower VCC range (1.65V–3.6V); 24mA drive; 3.3ns delay at 3.3V | Optimized for modern low-voltage portable designs; not 5.5V-tolerant | Choose for space-constrained 3.3V-only applications where smaller footprint and lower power outweigh voltage flexibility |
Compared with SN74AHC240DW, SN74AHCT240DW offers TTL-compatible input thresholds for legacy integration, while SN74LVC240APW provides superior speed and density in 3.3V systems but sacrifices 5.5V input tolerance and SOIC packaging familiarity.
Availability
SN74AHC240DW is available at Aetrix Electronics and suitable for smartphone handset design, network switch backplane development, and industrial PLC I/O expansion requiring stable component supply and long-term manufacturability assurance.
Supply support for SN74AHC240DW 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 markets.
The SN74AHC240DW belongs to TI's AHC logic family, engineered for high-speed, low-power, 3-state bus interface applications in mixed-voltage digital systems.
FAQ
What is the maximum supply voltage for SN74AHC240DW?
The absolute maximum supply voltage for SN74AHC240DW is 7V, but its recommended operating range is 2V to 5.5V. Operating within this range ensures full compliance with electrical specifications including VOH/VOL, propagation delay, and output drive. Exceeding 5.5V may cause parametric deviation or accelerated aging, even if below the 7V absolute limit.
Does SN74AHC240DW support hot-swap or live-insertion?
SN74AHC240DW does not include built-in hot-swap protection circuitry. However, its 5.5V-tolerant inputs and high-impedance outputs when OE is asserted allow controlled insertion into powered-backplane systems - provided VCC sequencing and current-limiting measures are implemented externally per TI application guidelines.
Can SN74AHC240DW drive LEDs directly?
Yes, SN74AHC240DW can drive LEDs directly: each output supports up to 25mA sink/source, sufficient for indicator LEDs with appropriate series resistors. For example, at 3.3V VCC and 1.8V LED forward voltage, a 60Ω resistor limits current to ~25mA. Ensure total device current stays ≤75mA (sum across all active outputs).
Is SN74AHC240DW pin-compatible with SN74LS240?
No, SN74AHC240DW is not pin-compatible with SN74LS240. While both are octal 3-state buffers, SN74LS240 uses a different pinout (e.g., OE placement, power/ground locations) and TTL logic thresholds. Direct replacement requires PCB redesign. Use SN74AHCT240DW instead for TTL-compatible pinout and thresholds.
What is the thermal resistance (RθJA) of SN74AHC240DW?
The junction-to-ambient thermal resistance (RθJA) for SN74AHC240DW in SOIC-20 package is 81.1°C/W, measured under standard JEDEC conditions (1s² copper pad, no airflow). This value assumes proper PCB layout with adequate copper pour and thermal vias - derating is required above 70°C ambient or under high-power sustained load.
SN74AHC240DW Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74AHC
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Logic Type:
- Buffer, Inverting
- Number of Elements:
- 2
- Number of Bits per Element:
- 4
- Input Type:
- -
- Output Type:
- 3-State
- Current - Output High, Low:
- 8mA, 8mA
- Voltage - Supply:
- 2V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SOIC
SN74AHC240DW FAQ
1.How can I place an order for SN74AHC240DW through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74AHC240DW 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 SN74AHC240DW reliable?
The price and inventory of SN74AHC240DW are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74AHC240DW is usually 5 days.
3.What payment methods are accepted for SN74AHC240DW?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74AHC240DW transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74AHC240DW?
SN74AHC240DW orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74AHC240DW 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 SN74AHC240DW?
For technical support, including SN74AHC240DW datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74AHC240DW requirements.
6.How does Aetrix verify that SN74AHC240DW is sourced from the original manufacturer or authorized distributors?
All SN74AHC240DW 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 SN74AHC240DW meets industry standards.
7.What is the process for return or replacement of SN74AHC240DW?
All SN74AHC240DW units undergo pre-shipment inspection (PSI). If there is an issue with SN74AHC240DW, 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 SN74AHC240DW part is unused and in its original packaging.
Return procedure for SN74AHC240DW:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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