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Texas Instruments SN74AHCT240PWG4
- Part No.:
- SN74AHCT240PWG4
- Manufacturer:
- Texas Instruments
- Package:
- 20-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
SN74AHCT240PWG4.pdf
- Description:
- IC BUFFER INVERT 5.5V 20TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,912
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Product details
Overview
SN74AHCT240PWG4 from Texas Instruments is an octal inverting buffer/driver with tri-state outputs, designed for bus-oriented receivers and transmitters in 5-V digital systems. It features TTL-compatible inputs (VIH = 2 V, VIL = 0.8 V), ±8 mA output drive, 9.5 ns max propagation delay at 5 V/50 pF, and operates from –40°C to +125°C. It serves as a level-shifting interface between 3.3-V logic and 5-V buses in industrial control backplanes.
For engineers reviewing the SN74AHCT240PWG4 datasheet, SN74AHCT240PWG4 pinout, SN74AHCT240PWG4 application, or SN74AHCT240PWG4 equivalent, key selection criteria include its inverting tri-state behavior, 5-V-only supply operation, TSSOP-20 package footprint, and compatibility with legacy TTL input thresholds in mixed-voltage memory address or clock distribution paths.
Technical Context
The SN74AHCT240PWG4 implements two independent 4-bit inverting buffer sections, each with dedicated output-enable (OE) control. Its CMOS design uses buffered inputs and totem-pole outputs, enabling bidirectional bus isolation when OE is high (high-Z state) and inverted data transmission when OE is low.
It operates strictly at 5-V supply (4.5–5.5 V), accepts 3.3-V TTL-level inputs without level shifters, and delivers slow edge rates to suppress output ringing on unterminated traces - critical for noise-sensitive industrial and broadcast equipment signal integrity.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5 V to 5.5 V - Requires stable 5-V rail; not 3.3-V operable. |
| Input Thresholds | VIH = 2.0 V, VIL = 0.8 V - Directly interfaces TTL and 3.3-V CMOS logic without translation. |
| Output Drive | ±8 mA at VCC = 4.5 V - Sufficient for driving 50-pF loads across PCB traces up to ~10 cm. |
| Propagation Delay | 9.5 ns max (A→Y, CL = 50 pF) - Enables reliable operation up to ~50 MHz bus toggle rates. |
| Operating Temperature | –40°C to +125°C - Qualified for under-hood automotive modules and industrial PLC I/O cards. |
| ESD Rating | HBM ±2000 V - Meets IEC 61000-4-2 Level 2 for board-level handling robustness. |
| Power Dissipation | Cpd = 10 pF - Predictable dynamic power consumption for thermal modeling in dense layouts. |
Pinout & Package
TSSOP-20 (PW) package: 6.50 mm × 6.40 mm body size, 0.65 mm lead pitch, thin-profile surface-mount construction suitable for automated assembly and space-constrained applications.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 19 | 1OE, 2OE | Active-low enable inputs - Tie high via pull-up to ensure high-Z during power-up sequencing. |
| 2, 4, 6, 8, 11, 13, 15, 17 | 1A1–1A4, 2A1–2A4 | Inverting input terminals - Accept TTL/CMOS logic; VI ≤ 5.5 V absolute max. |
| 3, 5, 7, 9, 12, 14, 16, 18 | 2Y4–2Y1, 1Y4–1Y1 | Inverting tri-state outputs - High-Z when corresponding OE = high; otherwise Y = NOT(A). |
| 10 | GND | Ground reference - Must be low-inductance connection to minimize switching noise coupling. |
| 20 | VCC | 5-V power supply - Requires local 0.1 µF ceramic bypass capacitor placed <2 mm from pin. |
Key Features
| Feature | Design Value |
|---|---|
| TTL-voltage compatible inputs | Accepts 0.8 V / 2.0 V thresholds - Eliminates need for external level translators when interfacing 3.3-V microcontrollers to 5-V peripherals. |
| Slow edge rate control | Minimizes overshoot/undershoot on unterminated lines - Reduces EMI and eliminates need for series termination resistors in cost-sensitive designs. |
| Tri-state output architecture | Two independent 4-bit sections with separate OE pins - Enables selective bus arbitration without external logic or multiplexers. |
| Latch-up immunity | Exceeds 250 mA per JESD17 - Ensures robustness against transient ground bounce or hot-swap events in modular systems. |
| 5-V optimized CMOS process | Guaranteed performance at 4.5–5.5 V - Delivers consistent timing and drive strength across full industrial temperature range. |
Applications
| Industrial PLC Backplane Interface | Automotive Body Control Module |
|---|---|
Use Scenario: Isolating microcontroller GPIOs from noisy 5-V sensor bus in programmable logic controller racks. IC Role / Device Role / Timing Role: Inverting tri-state buffer providing direction-controlled data path between ARM Cortex-M4 and legacy 5-V analog front-end ICs. Use Value: Prevents bus contention during firmware updates by disabling outputs via OE while maintaining TTL-compatible input thresholds for diagnostic polling. |
Use Scenario: Driving multiple 5-V LED indicators and relay drivers from a 3.3-V CAN microcontroller in door module assemblies. IC Role / Device Role / Timing Role: Level-shifting buffer translating MCU GPIO states to 5-V logic levels while suppressing EMI from inductive loads. Use Value: Slow edge rates reduce conducted emissions below CISPR 25 Class 3 limits without added ferrites or RC snubbers. |
| Medical Imaging Signal Conditioning | Broadcast Equipment Timing Distribution |
Use Scenario: Buffering TTL-level trigger signals from FPGA-based image acquisition boards to 5-V CCD driver circuits. IC Role / Device Role / Timing Role: Low-skew inverting repeater ensuring deterministic setup/hold margins across multi-board chassis interconnects. Use Value: 1 ns max output skew (tsk(o)) maintains sub-ns timing alignment required for synchronized pixel clock distribution. |
Use Scenario: Fan-out and inversion of SMPTE 2110 PTP reference clocks across video processing blades in 19-inch rack systems. IC Role / Device Role / Timing Role: Tri-state-capable clock driver enabling dynamic reconfiguration of timing tree topology during system boot. Use Value: Independent OE control allows hot-swapping of processing modules without disrupting master clock integrity on shared backplane. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal inverting buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74AHCT240PWR | Identical electrical specs and pinout; same TSSOP-20 package but standard NIPDAU finish (no G4 suffix). | No functional difference; G4 denotes RoHS-compliant green mold compound and matte tin finish per TI spec. | Select SN74AHCT240PWR if non-green material qualification is required for aerospace or military programs. |
| 74LVC240APW | 3.3-V only supply (1.65–3.6 V); lower drive (±24 mA); faster propagation (3.4 ns typ); no TTL input compatibility. | Not suitable for 5-V bus interfacing; requires external level shifting for legacy 5-V peripherals. | Choose only for new 3.3-V-only designs where higher speed and lower power outweigh voltage translation needs. |
Compared with SN74AHCT240PWR, SN74AHCT240PWG4 offers identical functionality with enhanced environmental compliance; versus 74LVC240APW, it trades speed and power efficiency for essential 5-V operation and TTL input tolerance in mixed-voltage systems.
Availability
SN74AHCT240PWG4 is available at Aetrix Electronics and suitable for industrial PLC backplanes, automotive body control modules, medical imaging subsystems, and broadcast timing distribution requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for SN74AHCT240PWG4 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 50 years of innovation in industrial, automotive, and communications markets.
The SN74AHCT240PWG4 belongs to TI's legacy 74AHCT logic family, engineered for robust 5-V bus interfacing in harsh environments where reliability, noise immunity, and backward compatibility with TTL systems are critical design requirements.
FAQ
What is the maximum operating temperature for SN74AHCT240PWG4?
The SN74AHCT240PWG4 is rated for continuous operation from –40°C to +125°C ambient temperature. This specification is validated per JEDEC JESD22-A108 and applies to the TSSOP-20 (PW) package variant. Thermal derating is not required within this range when mounted on standard FR-4 PCBs with typical copper pour; junction temperature remains within safe limits under worst-case load conditions.
Does SN74AHCT240PWG4 support 3.3-V input logic levels?
Yes, SN74AHCT240PWG4 accepts 3.3-V logic inputs reliably: its VIH threshold is 2.0 V minimum and VIL is 0.8 V maximum, fully compatible with standard 3.3-V CMOS and TTL outputs. No external level shifter is needed when driving SN74AHCT240PWG4 from 3.3-V microcontrollers or FPGAs - a key advantage over pure 5-V families like 74ACT.
Can SN74AHCT240PWG4 operate from a 3.3-V supply?
No, SN74AHCT240PWG4 requires a 4.5–5.5-V supply and is not functional at 3.3 V. Its internal circuitry is optimized for 5-V operation, and attempting to power it at 3.3 V results in undefined output states, excessive ICC current, and potential latch-up. For 3.3-V supply compatibility, consider the 74LVC240 series instead.
What is the purpose of the G4 suffix in SN74AHCT240PWG4?
The G4 suffix in SN74AHCT240PWG4 indicates Texas Instruments' green packaging standard: matte tin lead finish, halogen-free mold compound, and RoHS-compliant materials per EU Directive 2011/65/EU. It does not affect electrical performance or pinout - SN74AHCT240PWG4 is functionally identical to SN74AHCT240PWR but meets stricter environmental compliance requirements for export to regulated markets.
How should unused inputs be handled on SN74AHCT240PWG4?
All unused inputs on SN74AHCT240PWG4 must be tied to either VCC or GND - floating inputs cause increased ICC, unpredictable output states, and potential oscillation. TI recommends connecting unused A-inputs directly to VCC or GND using short PCB traces; OE inputs should be pulled high (to VCC) via ≤10-kΩ resistor to guarantee high-impedance outputs during power-up.
SN74AHCT240PWG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74AHCT
- Package/Case:
- 20-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tube
- Product Status:
- Discontinued at Digi-Key
- 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:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-TSSOP
SN74AHCT240PWG4 FAQ
1.How can I place an order for SN74AHCT240PWG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74AHCT240PWG4 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 SN74AHCT240PWG4 reliable?
The price and inventory of SN74AHCT240PWG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74AHCT240PWG4 is usually 5 days.
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SN74AHCT240PWG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74AHCT240PWG4 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 SN74AHCT240PWG4?
For technical support, including SN74AHCT240PWG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74AHCT240PWG4 requirements.
6.How does Aetrix verify that SN74AHCT240PWG4 is sourced from the original manufacturer or authorized distributors?
All SN74AHCT240PWG4 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 SN74AHCT240PWG4 meets industry standards.
7.What is the process for return or replacement of SN74AHCT240PWG4?
All SN74AHCT240PWG4 units undergo pre-shipment inspection (PSI). If there is an issue with SN74AHCT240PWG4, 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 SN74AHCT240PWG4 part is unused and in its original packaging.
Return procedure for SN74AHCT240PWG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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