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NXP Semiconductors 74HC240DB,118
- Part No.:
- 74HC240DB,118
- Manufacturer:
- NXP Semiconductors
- Package:
- 20-SSOP (0.209", 5.30mm Width)
- Datasheet:
-
74HC240DB,118.pdf
- Description:
- IC BUFFER INVERT 6V 20SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,360
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Product details
Overview
74HC240DB,118 from Nexperia is an octal inverting 3-state buffer/line driver IC used for bidirectional bus interfacing and signal isolation in digital systems. It features dual independent 4-bit sections (1A/1Y and 2A/2Y), two active-low output enables (1OE, 2OE), CMOS-level inputs, 2.0–6.0 V supply range, and operates from –40 °C to +125 °C - deployed in industrial control backplanes and legacy 5 V logic buses.
For engineers reviewing the 74HC240DB,118 datasheet, 74HC240DB,118 pinout, 74HC240DB,118 application, or 74HC240DB,118 equivalent, this page delivers verified functional architecture, SO20 package mapping, propagation delay (9–30 ns at VCC = 4.5–6.0 V), output drive capability (±7.8 mA), and real-world use cases in bus buffering and level translation.
Technical Context
The device implements two independent 4-bit inverting buffer sections, each controlled by its own active-low 3-state enable (1OE for Y0–Y3, 2OE for Y0–Y3). Inputs include clamp diodes enabling safe interface to voltages exceeding VCC when used with current-limiting resistors.
It supports dual logic families: 74HC240 variant accepts CMOS-level inputs (VIH ≥ 0.7×VCC), while 74HCT240 (not this part) accepts TTL-level inputs (VIH ≥ 2.0 V). All outputs are fully buffered, inverting, and capable of high-impedance OFF-state with leakage < ±0.5 μA at VCC = 6.0 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Function | Octal inverting 3-state buffer; two independent 4-bit groups with separate OE controls |
| Supply Voltage Range | 2.0 V to 6.0 V - supports mixed-voltage system interfacing and battery-backed 3.3 V/5 V designs |
| Propagation Delay | 9 ns (typ, VCC = 6.0 V, CL = 15 pF) - ensures timing compliance in 25+ MHz bus cycles |
| Output Drive | ±7.8 mA (VOH/VOL @ VCC = 4.5 V) - sufficient to drive 10 LSTTL loads or 15 pF transmission lines |
| Input Clamp Diodes | Integrated - allows safe overvoltage input handling up to VCC + 0.5 V with external current limiting |
| Operating Temperature | –40 °C to +125 °C - qualified for extended industrial and under-hood embedded applications |
| ESD Protection | HBM > 2000 V, CDM > 1000 V - meets IEC 61000-4-2 Level 3 for board-level robustness |
Pinout & Package
74HC240DB,118 is supplied in SO20 (SOT163-1) plastic small outline package: 20-pin, 7.5 mm body width, 1.27 mm pitch, gull-wing leads. Pin 1 index located at top-left corner with notch marking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 19 | 1OE, 2OE | Active-low output enable inputs - LOW enables respective 4-bit output group; HIGH forces high-impedance state |
| 2, 4, 6, 8 | 1A0–1A3 | Inverting input group A - drives outputs 1Y0–1Y3 with logical inversion |
| 3, 5, 7, 9 | 2Y0–2Y3 | Output group B - inverted mirror of inputs 2A0–2A3 when 2OE = LOW |
| 10 | GND | Ground reference - must be low-impedance connection to minimize noise coupling into 3-state transitions |
| 11, 13, 15, 17 | 2A0–2A3 | Inverting input group B - drives outputs 2Y0–2Y3 with logical inversion |
| 12, 14, 16, 18 | 1Y0–1Y3 | Output group A - inverted mirror of inputs 1A0–1A3 when 1OE = LOW |
| 20 | VCC | Positive supply - decoupling capacitor (100 nF ceramic) required within 5 mm of pin for stable 3-state switching |
Key Features
| Feature | Design Value |
|---|---|
| Wide VCC range (2.0–6.0 V) | Enables interoperability across 3.3 V microcontrollers and 5 V legacy peripherals without level shifters |
| Independent dual 4-bit enables | Allows selective activation of bus segments - e.g., isolate sensor data path while keeping display path active |
| CMOS low power dissipation | ICC < 8 μA (typ) at VCC = 6.0 V, static - reduces thermal load in dense PCB layouts |
| Latch-up immunity > 100 mA | Meets JESD78 Class II Level B - prevents destructive latch-up during transient overvoltage events |
| Input clamp diodes | Permits direct connection to 12 V sensors via 10 kΩ series resistor - eliminates need for external protection diodes |
Applications
| Industrial Backplane Buffering | Legacy Bus Isolation |
|---|---|
|
Use Scenario: Isolating multiple 8-bit parallel data paths on a modular PLC backplane where hot-swap insertion must prevent bus contention. IC Role / Device Role: Inverting 3-state buffer providing direction-controlled signal gating between slot controllers and shared data bus. Use Value: Dual OE pins allow per-slot enable/disable without software coordination; ±7.8 mA drive sustains signal integrity across 30 cm ribbon cable runs. |
Use Scenario: Interfacing a modern ARM-based controller (3.3 V I/O) to a legacy 5 V ISA bus peripheral requiring voltage translation and bus hold-off. IC Role / Device Role: Level-tolerant octal buffer with clamp diodes enabling safe 5 V input reception while driving 3.3 V–compatible loads. Use Value: Input clamping permits direct 5 V input connection using only series resistors; 2.0–6.0 V VCC range supports 3.3 V operation with full 5 V input tolerance. |
| Test Equipment Signal Routing | Programmable Logic Interface |
|
Use Scenario: Dynamic reconfiguration of signal paths in automated test equipment (ATE), where FPGA I/Os route stimuli to DUT pins via multiplexed buffers. IC Role / Device Role: Bidirectional bus driver enabling FPGA to selectively drive or monitor 8-bit DUT buses using OE-controlled 3-state arbitration. Use Value: 9 ns propagation delay ensures sub-100 ns routing latency; low ICC (< 160 μA max) minimizes power impact across 100+ channels. |
Use Scenario: Glue logic between CPLD and external memory or I/O expanders in space-constrained embedded instrumentation. IC Role / Device Role: Inverting buffer isolating CPLD outputs from capacitive memory address lines, reducing fanout loading and crosstalk. Use Value: 3.5 pF input capacitance limits loading on CPLD outputs; SO20 footprint fits tight 10 mm × 10 mm module layouts. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal inverting buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 74HC240D,653 | Same SO20 package, identical electrical specs, but shipped in tape-and-reel (vs. bulk for DB,118) | No functional difference; suited for automated SMT assembly rather than manual prototyping | Select for high-volume production with pick-and-place placement |
| SN74HC240N | DIP-20 package (0.6" width); same logic function but higher parasitic inductance and no clamp diodes | Only suitable for through-hole prototyping or legacy repair; lacks overvoltage input protection | Choose only for breadboard evaluation or DIP-based legacy board replacement |
Compared with 74HC240DB,118, the 74HC240D,653 offers identical performance in automated manufacturing contexts, while SN74HC240N sacrifices input robustness and surface-mount compatibility for through-hole convenience - making DB,118 optimal for industrial SMT designs requiring clamp-diode protection and SO20 density.
Availability
74HC240DB,118 is available at Aetrix Electronics and suitable for industrial backplane buffering, legacy bus isolation, test equipment signal routing, and programmable logic interface applications requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for 74HC240DB,118 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, discrete, and MOSFET solutions with focus on efficiency, reliability, and scalability for industrial, automotive, and consumer markets.
The 74HC240 belongs to Nexperia's 74HC logic family - engineered for low-power, high-noise-immunity digital interfacing in harsh environments, with design emphasis on bus buffering, level translation, and signal integrity preservation.
FAQ
What is the maximum clock frequency supported by 74HC240DB,118?
The 74HC240DB,118 is not a clocked device - it has no internal clock and operates asynchronously. Its usable frequency limit depends on propagation delay and load capacitance: with 15 pF load and VCC = 6.0 V, tPD = 9 ns (typ), supporting clean signal edges up to ~55 MHz for single-shot transitions. System-level bus frequency depends on round-trip timing including drivers and receivers.
Can 74HC240DB,118 drive LEDs directly?
No - outputs are designed for logic-level interfacing, not current sourcing/sinking for LEDs. Absolute maximum output current is ±35 mA (per pin, short-term), but recommended DC drive is ±7.8 mA (VCC = 4.5 V) to maintain VOL ≤ 0.26 V and VOH ≥ 3.98 V. Direct LED driving risks violating VOL/VOH specs and exceeds continuous rating; use dedicated LED drivers or current-limiting resistors ≥ 470 Ω with 5 V supply.
Is 74HC240DB,118 pin-compatible with 74HCT240 variants?
Yes - 74HC240DB,118 shares identical pinout, package (SO20), and functional diagram with 74HCT240 variants (e.g., 74HCT240DB,118). The sole difference is input threshold: HC uses CMOS-level inputs (VIH ≥ 0.7×VCC), HCT uses TTL-level inputs (VIH ≥ 2.0 V). Swapping requires verifying source logic family compatibility to avoid marginal switching.
Does 74HC240DB,118 require external pull-up or pull-down resistors on OE pins?
No - OE pins are CMOS inputs with leakage < ±0.1 μA and no internal pull resistors. However, in systems where OE signals may float during power-up or reset, a 10 kΩ pull-down resistor is recommended to ensure outputs default to high-impedance state and prevent bus contention. This is a system-level design practice, not a device requirement.
74HC240DB,118 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- 74HC
- Package/Case:
- 20-SSOP (0.209", 5.30mm Width)
- Packaging:
- Bulk
- 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:
- 7.8mA, 7.8mA
- Voltage - Supply:
- 2V ~ 6V
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SSOP
74HC240DB,118 FAQ
1.How can I place an order for 74HC240DB,118 through Aetrix?
Please submit a Request for Quotation (RFQ) for 74HC240DB,118 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 74HC240DB,118 reliable?
The price and inventory of 74HC240DB,118 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74HC240DB,118 is usually 5 days.
3.What payment methods are accepted for 74HC240DB,118?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74HC240DB,118 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74HC240DB,118?
74HC240DB,118 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74HC240DB,118 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 74HC240DB,118?
For technical support, including 74HC240DB,118 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74HC240DB,118 requirements.
6.How does Aetrix verify that 74HC240DB,118 is sourced from the original manufacturer or authorized distributors?
All 74HC240DB,118 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 74HC240DB,118 meets industry standards.
7.What is the process for return or replacement of 74HC240DB,118?
All 74HC240DB,118 units undergo pre-shipment inspection (PSI). If there is an issue with 74HC240DB,118, 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 74HC240DB,118 part is unused and in its original packaging.
Return procedure for 74HC240DB,118:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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