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Nexperia USA Inc. 74HCT240D,653
- Part No.:
- 74HCT240D,653
- Manufacturer:
- Nexperia USA Inc.
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
74HCT240D,653.pdf
- Description:
- IC BUFFER INVERT 5.5V 20SO
- Quantity:
- Payment:
- Shipping:
Inventory:1,014
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Product details
Overview
74HCT240D,653 from Nexperia is an octal inverting 3-state buffer/line driver IC used for bus interface and signal isolation in digital systems. It features dual independent 4-bit sections (1A/1Y and 2A/2Y), TTL-compatible input thresholds (VIH = 2.0 V min, VIL = 0.8 V max at VCC = 5 V), ±6 mA output drive, and operates across -40 °C to +125 °C. It enables bidirectional bus control in industrial PLC I/O modules.
For engineers reviewing the 74HCT240D,653 datasheet, 74HCT240D,653 pinout, 74HCT240D,653 application, or 74HCT240D,653 equivalent, key selection criteria include TTL-level input compatibility, 3-state enable timing (ten = 13–45 ns), propagation delay (tpd = 9–30 ns), and SO20 package thermal performance under sustained bus loading.
Technical Context
The 74HCT240D,653 implements two independent 4-bit inverting buffers, each controlled by a dedicated active-low output enable (1OE, 2OE). Its TTL-compatible inputs accept standard 5 V logic levels while operating from a 4.5–5.5 V supply, ensuring interoperability with legacy microcontroller and FPGA I/O banks.
All eight outputs are 3-state capable with high-impedance OFF-state leakage ≤ ±5 μA at VCC = 5.5 V. The device uses CMOS silicon with clamp diodes on all inputs, permitting safe interfacing to voltages exceeding VCC when current-limited.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Function | Inverting octal buffer with dual 3-state control (1OE/2OE) |
| Supply Voltage Range | 4.5 V to 5.5 V - matches standard 5 V TTL and mixed-voltage system rails |
| Input Thresholds | VIH = 2.0 V min, VIL = 0.8 V max - ensures reliable recognition of 5 V TTL signals |
| Output Drive | ±6 mA at VCC = 4.5 V - sufficient to drive 50 Ω transmission lines or 10 LSTTL loads |
| Propagation Delay | 9 ns typ (VCC = 5 V, CL = 15 pF) - supports >20 MHz bus toggle rates |
| Enable/Disable Time | ten = 13 ns typ, tdis = 13 ns typ - enables fast bus arbitration in multiplexed systems |
| Operating Temperature | -40 °C to +125 °C - qualified for under-hood automotive and industrial control environments |
Pinout & Package
74HCT240D,653 is housed in a plastic small outline package (SO20, SOT163-1) with 20 leads and 7.5 mm body width. Pin 1 is marked by a notch or dot; the package is RoHS-compliant and rated for reflow soldering per JEDEC J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 19 | 1OE, 2OE | Active-low output enables - each controls four corresponding Y outputs independently |
| 2, 4, 6, 8 | 1A0–1A3 | First 4-bit inverting input group - drives 1Y0–1Y3 when 1OE = LOW |
| 3, 5, 7, 9 | 2Y0–2Y3 | Second 4-bit inverting output group - driven by 2A0–2A3 when 2OE = LOW |
| 10 | GND | Signal ground reference - must be low-impedance connection for noise immunity |
| 11, 13, 15, 17 | 2A0–2A3 | Second 4-bit inverting input group - drives 2Y0–2Y3 when 2OE = LOW |
| 12, 14, 16, 18 | 1Y0–1Y3 | First 4-bit inverting output group - driven by 1A0–1A3 when 1OE = LOW |
| 20 | VCC | Positive supply - bypass with 100 nF ceramic capacitor near pin for stable operation |
Key Features
| Feature | Design Value |
|---|---|
| TTL-compatible inputs | VIH ≥ 2.0 V, VIL ≤ 0.8 V at VCC = 5 V - eliminates level-shifting in 5 V systems |
| Independent dual 3-state control | Separate 1OE/2OE pins - allows interleaved bus access without contention |
| Input clamp diodes | Enables use of series current-limiting resistors for overvoltage-tolerant input interfacing |
| High noise immunity | Typical noise margin >1.2 V at VCC = 5 V - robust against EMI in industrial enclosures |
| ESD protection | HBM >2000 V, CDM >1000 V - reduces handling sensitivity during PCB assembly |
Applications
| Industrial PLC I/O Expansion | Legacy Microcontroller Bus Isolation |
|---|---|
Use Scenario: Adding isolated digital input/output channels to a programmable logic controller rack using shared backplane data lines. IC Role / Device Role / Timing Role: Inverting 3-state buffer isolating field-side sensors/actuators from CPU bus; enables hot-swap-safe channel enable/disable via OE control. Use Value: Prevents bus contention during module insertion/removal and provides 125 °C operation for cabinet-mounted controllers. |
Use Scenario: Interfacing an 8-bit 8051 microcontroller with multiple peripheral chips sharing a common address/data bus. IC Role / Device Role / Timing Role: Direction-controlled bus driver translating MCU outputs to peripheral inputs while blocking reverse current flow. Use Value: Enables clean signal integrity with <30 ns propagation delay and ±6 mA drive into 50 Ω traces. |
| FPGA-to-ASIC Signal Conditioning | Test Equipment Digital Pattern Generation |
Use Scenario: Level-shifting and buffering between a 3.3 V FPGA I/O bank and a 5 V ASIC subsystem requiring TTL-compatible inputs. IC Role / Device Role / Timing Role: Inverting buffer converting FPGA logic levels to 5 V TTL thresholds; 3-state capability supports bidirectional test mode switching. Use Value: Eliminates external level shifters; VIH/VIL specs guarantee deterministic sampling at 20 MHz clock rates. |
Use Scenario: Driving multiple parallel digital stimulus channels in automated test equipment with precise timing alignment. IC Role / Device Role / Timing Role: Synchronized 8-bit pattern driver with matched propagation delays across all outputs for skew-critical vector generation. Use Value: <1 ns inter-output skew (typ) and 13 ns enable time support sub-50 ns pulse edge placement accuracy. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal inverting 3-state buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74HCT240N | DIP-20 package; no lead-free finish; wider temp range (-55 °C to +125 °C) | Suitable for through-hole prototyping and military-grade thermal cycling | Select for breadboard evaluation or legacy DIP-based designs requiring extended cold tolerance |
| 74HCT240PW,118 | TSSOP-20 package (4.4 mm width); 100 °C max junction temperature; 10.0 mW/K derating | Better board density and thermal performance in space-constrained embedded controllers | Select for high-density PCBs where SO20 footprint is prohibitive and thermal load exceeds 350 mW |
Compared with SN74HCT240N and 74HCT240PW,118, the 74HCT240D,653 offers optimal balance of industrial temperature rating, SO20 manufacturability, and legacy system compatibility - making it preferred for volume production of DIN-rail mounted automation hardware.
Availability
74HCT240D,653 is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, legacy microcontroller bus isolation, FPGA-to-ASIC signal conditioning, and test equipment digital pattern generation requiring stable component supply across extended temperature ranges.
Supply support for 74HCT240D,653 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
Nexperia is a global semiconductor expert delivering high-performance logic, analog, and MOSFET solutions optimized for efficiency, reliability, and manufacturability in high-volume applications.
The 74HCT240D,653 belongs to Nexperia's industry-standard 74HCT logic family, designed specifically for robust 5 V TTL-compatible interfacing in industrial control, instrumentation, and communications infrastructure.
FAQ
Can 74HCT240D,653 operate at 3.3 V supply?
No. The 74HCT240D,653 is specified only for 4.5 V to 5.5 V operation per its recommended conditions. At 3.3 V, input thresholds (VIH ≥ 2.0 V) remain valid, but VOH drops below 2.4 V and VOL rises above 0.4 V, violating TTL compatibility. Use 74LVC240 for 3.3 V systems.
What is the maximum capacitive load per output?
The datasheet specifies dynamic characteristics up to 50 pF load capacitance. With CL = 50 pF and VCC = 5 V, propagation delay increases to 30 ns max and transition time to 18 ns max. For reliable 20 MHz operation, keep total load (trace + receiver input) ≤ 30 pF per output.
How should unused inputs be terminated?
All unused inputs (1A0–1A3, 2A0–2A3, 1OE, 2OE) must be tied HIGH or LOW via ≤1 kΩ resistor. Leaving them floating risks increased ICC, noise susceptibility, and potential latch-up due to internal parasitic paths. Unused outputs may be left open when their respective OE is HIGH.
Does 74HCT240D,653 support hot-swap insertion?
Yes - its input clamp diodes and 3-state outputs allow safe insertion into a live 5 V bus when current-limiting resistors (≥100 Ω) are used on all inputs. However, ensure 1OE/2OE are held HIGH during insertion to prevent output contention until firmware initializes the device.
74HCT240D,653 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- 74HCT
- Package/Case:
- 20-SOIC (0.295", 7.50mm 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:
- 6mA, 6mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SO
74HCT240D,653 FAQ
1.How can I place an order for 74HCT240D,653 through Aetrix?
Please submit a Request for Quotation (RFQ) for 74HCT240D,653 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 74HCT240D,653 reliable?
The price and inventory of 74HCT240D,653 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74HCT240D,653 is usually 5 days.
3.What payment methods are accepted for 74HCT240D,653?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74HCT240D,653 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74HCT240D,653?
74HCT240D,653 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74HCT240D,653 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 74HCT240D,653?
For technical support, including 74HCT240D,653 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74HCT240D,653 requirements.
6.How does Aetrix verify that 74HCT240D,653 is sourced from the original manufacturer or authorized distributors?
All 74HCT240D,653 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 74HCT240D,653 meets industry standards.
7.What is the process for return or replacement of 74HCT240D,653?
All 74HCT240D,653 units undergo pre-shipment inspection (PSI). If there is an issue with 74HCT240D,653, 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 74HCT240D,653 part is unused and in its original packaging.
Return procedure for 74HCT240D,653:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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