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Texas Instruments SN74AHC240NSR
- Part No.:
- SN74AHC240NSR
- Manufacturer:
- Texas Instruments
- Package:
- 20-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
SN74AHC240NSR.pdf
- Description:
- IC BUFFER INVERT 5.5V 20SO
- Quantity:
- Payment:
- Shipping:
Inventory:123
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Product details
Overview
SN74AHC240NSR from Texas Instruments is an octal 3-state buffer/driver IC designed for bus-oriented applications including memory address drivers, clock distribution, and bidirectional data transmission. It features dual 4-bit sections with independent output-enable (OE) controls, 5.5V-tolerant inputs, 8mA output drive at 5V, and propagation delay as low as 3.6ns (typical, 5V, CL=15pF). It operates across –40°C to +85°C in SOP-20 packaging.
For engineers reviewing the SN74AHC240NSR datasheet, SN74AHC240NSR pinout, SN74AHC240NSR application, or SN74AHC240NSR equivalent, key selection criteria include its dual 4-bit 3-state architecture, wide VCC range (2V–5.5V), input overvoltage tolerance, low propagation delay, and thermal performance in SOP-20 (RθJA = 60°C/W).
Technical Context
The SN74AHC240NSR implements two independent 4-bit non-inverting buffer sections, each controlled by a dedicated OE input (1OE and 2OE). When OE is low, data passes from A inputs to Y outputs; when high, outputs enter high-impedance state - enabling bidirectional bus control without external logic.
Its AHC logic family delivers CMOS-level power efficiency with TTL-compatible drive strength: 8mA sink/source at 5V, 4mA at 3.3V, and 50µA at 2V. Input thresholds scale with VCC (VIH = 0.7×VCC, VIL = 0.3×VCC), and inputs tolerate up to 5.5V regardless of VCC - supporting mixed-voltage interfacing.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 2V to 5.5V - supports operation across 2.5V, 3.3V, and 5V logic domains with single supply. |
| Propagation Delay (tPLH/tPHL) | 3.6ns typ. @ 5V, CL=15pF - enables reliable timing in high-speed digital interfaces up to ~100MHz. |
| Output Drive (IOL/IOH) | ±8mA @ 5V - sufficient to drive multiple CMOS loads or light capacitive buses without buffering. |
| Input Voltage Tolerance | Up to 5.5V independent of VCC - allows safe interfacing with higher-voltage controllers or legacy 5V peripherals. |
| Operating Temperature | –40°C to +85°C - qualified for industrial-grade embedded systems and consumer electronics. |
| Quiescent Current (ICC) | 4µA typ. @ 5.5V - ensures ultra-low static power in battery-sensitive or always-on applications. |
| ESD Rating (HBM) | ±2000V - meets standard handling requirements for automated assembly and field deployment. |
Pinout & Package
SOP-20 (Small Outline Package, 12.60mm × 7.8mm body size, 12.60mm × 5.30mm footprint) with gull-wing leads, RoHS-compliant NIPDAU finish, and moisture sensitivity level (MSL) 1 (260°C peak reflow).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1OE, 19 | Output Enable 1 | Active-low control for first 4-bit buffer section (Y1–Y4); ties to GND to enable, VCC to disable. |
| 2OE, 2 | Output Enable 2 | Active-low control for second 4-bit buffer section (Y1–Y4); independent of 1OE for flexible bus partitioning. |
| 1A1–1A4, 2–4,6,8 | Input Group 1 | Non-inverting inputs for first buffer section; accept 5.5V-tolerant signals regardless of VCC. |
| 2A1–2A4, 11,13,15,17 | Input Group 2 | Non-inverting inputs for second buffer section; electrically isolated from Group 1 for dual-bus isolation. |
| 1Y1–1Y4, 12,14,16,18 | Output Group 1 | Driven outputs corresponding to 2A inputs; enter high-Z when 2OE = high. |
| 2Y1–2Y4, 3,5,7,9 | Output Group 2 | Driven outputs corresponding to 1A inputs; enter high-Z when 1OE = high. |
| VCC, 20 | Power Supply | Primary supply pin; requires local 0.1µF bypass capacitor placed adjacent to pin for noise suppression. |
| GND, 10 | Ground Reference | Common return path for all I/O and internal logic; must be low-impedance and directly connected to system ground plane. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent 4-bit 3-state buffers | Enables simultaneous control of two separate 4-bit data paths (e.g., address/data multiplexing or dual-bus arbitration) without cross-talk. |
| 5.5V-tolerant inputs | Permits direct connection to 5V microcontrollers or FPGAs while operating at 3.3V or 2.5V VCC - eliminates level-shifter components. |
| Low propagation delay (3.6ns typ.) | Supports high-speed timing-critical applications such as clock fanout, memory address latching, and synchronous bus interfaces. |
| High noise immunity (VIH/VIL scaling) | Input thresholds track VCC (VIH = 0.7×VCC, VIL = 0.3×VCC), maintaining robust logic margins across supply voltage variations. |
| Thermal resistance (RθJA = 60°C/W) | Enables stable operation at full drive strength in compact PCB layouts without forced air or heatsinking under typical industrial conditions. |
Applications
| Memory Address Buffering | Industrial Bus Interface |
|---|---|
Use Scenario: Driving 16-bit address lines from a microcontroller to multiple SRAM or flash devices on a shared bus. IC Role / Device Role / Timing Role: Non-inverting 3-state buffer providing isolation and drive strength; enables time-multiplexed access via OE control. Use Value: Eliminates signal degradation across long traces; supports >100MHz address strobe rates with sub-4ns edge fidelity. |
Use Scenario: Interfacing a 3.3V FPGA I/O bank to legacy 5V peripheral modules (e.g., UART transceivers, ADCs) on a backplane. IC Role / Device Role / Timing Role: Level-translating bus driver with 5.5V-tolerant inputs and 3.3V-compatible outputs. Use Value: Removes need for discrete level shifters; maintains signal integrity and timing margin across mixed-voltage domains. |
| Smartphone Baseband Support | Network Switch Control Plane |
Use Scenario: Isolating and driving configuration signals (e.g., reset, chip select, mode select) between AP and modem SoC in mobile handsets. IC Role / Device Role / Timing Role: Low-power 3-state buffer enabling dynamic power gating of unused peripherals during sleep states. Use Value: Reduces leakage current in standby mode (ICC < 5µA); supports fast wake-up with deterministic propagation delay. |
Use Scenario: Buffering management interface signals (I²C, SPI, GPIO) between switch controller ASIC and PHY modules in enterprise switches. IC Role / Device Role / Timing Role: Robust bus driver with ±2000V HBM ESD protection and industrial temperature rating. Use Value: Ensures reliability in high-noise rack environments; withstands repeated hot-plug events without latch-up. |
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 |
|---|---|---|---|
| SN74AHCT240NSR | CMOS inputs with TTL-compatible thresholds (VIH = 2.0V min, VIL = 0.8V max); identical pinout and drive strength. | Better suited for interfacing with legacy 5V TTL logic; less tolerant of slow-rising inputs than AHC variant. | Select when interfacing with older 5V microcontrollers or logic families requiring TTL-level recognition. |
| SN74LVC240ANSR | Lower VCC range (1.65V–3.6V); 24mA drive at 3.3V; smaller VSSOP-20 option available. | Optimized for modern low-voltage systems (e.g., battery-powered wearables); not 5.5V-input tolerant. | Select for 3.3V-only designs requiring higher drive or space-constrained layouts where SOP-20 is unsuitable. |
Compared with SN74AHCT240NSR and SN74LVC240ANSR, the SN74AHC240NSR uniquely balances wide VCC flexibility (2V–5.5V), 5.5V input tolerance, and industrial temperature support - making it optimal for mixed-voltage, field-deployable, and upgrade-retrofit applications where voltage domain bridging is required.
Availability
SN74AHC240NSR is available at Aetrix Electronics and suitable for industrial bus interface, memory address buffering, and smartphone baseband support requiring stable component supply and long-term production continuity.
Supply support for SN74AHC240NSR 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 solutions, with decades of experience in logic IC design and manufacturing.
The SN74AHC240NSR belongs to TI's advanced high-speed CMOS (AHC) logic family, engineered for low-power, high-drive bus interfacing in industrial, communications, and consumer electronics systems.
FAQ
What is the maximum operating frequency supported by SN74AHC240NSR?
The SN74AHC240NSR does not have a specified maximum clock frequency, but its typical propagation delay of 3.6ns (5V, CL=15pF) supports reliable operation in digital systems with signal edges up to ~100MHz. System-level timing depends on load capacitance, trace routing, and VCC; for sustained 100MHz data rates, keep CL ≤ 15pF and use proper termination.
Can SN74AHC240NSR safely interface a 5V microcontroller with a 3.3V FPGA?
Yes. The SN74AHC240NSR accepts input voltages up to 5.5V regardless of VCC, so it can directly receive 5V logic signals while powered at 3.3V. Its outputs swing rail-to-rail (0V to 3.3V), making them compatible with 3.3V FPGA I/O standards - eliminating external level shifters in this configuration.
Does SN74AHC240NSR require pull-up resistors on its OE pins?
Not strictly required, but recommended during power-up/down sequencing. Tying 1OE and 2OE to VCC through a pull-up resistor (e.g., 10kΩ) ensures outputs remain in high-impedance state until firmware asserts OE low - preventing bus contention or unintended writes during reset.
What is the thermal performance of SN74AHC240NSR in SOP-20 package?
The SN74AHC240NSR in SOP-20 has a junction-to-ambient thermal resistance (RθJA) of 60°C/W. At full 8mA per output (4 outputs active), total power dissipation remains below 50mW, resulting in negligible temperature rise (<3°C) on standard FR-4 PCBs - no heatsink or airflow needed for typical use cases.
Is SN74AHC240NSR pin-compatible with other members of the SN74AHC240 family?
Yes - all SN74AHC240 variants (e.g., SN74AHC240N, SN74AHC240DWR, SN74AHC240PWR) share identical pinout and logic function. The SN74AHC240NSR uses SOP-20 packaging, differing only in mechanical form factor and thermal characteristics from SOIC-20 or TSSOP-20 versions.
SN74AHC240NSR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74AHC
- Package/Case:
- 20-SOIC (0.209", 5.30mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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-SO
SN74AHC240NSR FAQ
1.How can I place an order for SN74AHC240NSR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74AHC240NSR 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 SN74AHC240NSR reliable?
The price and inventory of SN74AHC240NSR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74AHC240NSR is usually 5 days.
3.What payment methods are accepted for SN74AHC240NSR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74AHC240NSR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74AHC240NSR?
SN74AHC240NSR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74AHC240NSR 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 SN74AHC240NSR?
For technical support, including SN74AHC240NSR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74AHC240NSR requirements.
6.How does Aetrix verify that SN74AHC240NSR is sourced from the original manufacturer or authorized distributors?
All SN74AHC240NSR 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 SN74AHC240NSR meets industry standards.
7.What is the process for return or replacement of SN74AHC240NSR?
All SN74AHC240NSR units undergo pre-shipment inspection (PSI). If there is an issue with SN74AHC240NSR, 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 SN74AHC240NSR part is unused and in its original packaging.
Return procedure for SN74AHC240NSR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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