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STMicroelectronics 74VHCT240ATTR
- Part No.:
- 74VHCT240ATTR
- Manufacturer:
- STMicroelectronics
- Package:
- 20-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
74VHCT240ATTR.pdf
- Description:
- IC BUFFER INVERT 5.5V 20TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,418
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Product details
Overview
74VHCT240ATTR from STMicroelectronics is an octal 3-state inverting bus buffer with TTL-compatible inputs, designed for bidirectional address/data bus isolation in 5V digital systems. It features 5.4 ns typical propagation delay, ±8 mA symmetrical output drive, 4 µA max quiescent current at 25°C, and operates across 4.5–5.5 V supply. Used in memory address driver interfaces where low-noise, latch-up-immune buffering is required.
For engineers reviewing the 74VHCT240ATTR datasheet, 74VHCT240ATTR pinout, 74VHCT240ATTR application, or 74VHCT240ATTR equivalent, key selection criteria include its inverted 3-state output architecture, dual enable control (1G/2G), input tolerance up to 7 V independent of VCC, and guaranteed 2 kV HBM ESD immunity on all pins.
Technical Context
This device implements two independent 4-bit inverting buffers, each controlled by a dedicated active-low output enable (1G, 2G). All inputs accept 0–7 V regardless of VCC, enabling safe level translation between 5 V and 3 V domains without external clamping.
Its C2MOS process delivers balanced tPLH/tPHL delays, power-down protection on all I/Os during VCC=0, and low dynamic noise (VOLP ≤ 0.9 V) due to controlled edge rates and internal capacitance management (CPD = 19 pF).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 4.5 V to 5.5 V - Ensures compatibility with standard 5 V TTL logic rails and tolerates ±10% supply variation. |
| tPD (Typ.) | 5.4 ns at VCC = 5 V, CL = 15 pF - Enables high-speed address/data bus operation up to ~185 MHz toggle rate. |
| IOL / IOH | ±8 mA min - Drives standard TTL loads (up to 10 LSTTL units) while maintaining VOL ≤ 0.55 V and VOH ≥ 3.7 V. |
| VIH / VIL | 2.0 V min / 0.8 V max - Guarantees robust interfacing with legacy TTL outputs without level shifters. |
| ICC (Max) | 4 µA at TA = 25°C - Supports ultra-low static power in standby or battery-backed subsystems. |
| ESD Rating | 2 kV HBM - Protects against handling damage in manual assembly and field-replaceable modules. |
| VIN Tolerance | −0.5 V to +7.0 V - Allows hot-plug and mixed-voltage I/O without external protection diodes. |
Pinout & Package
TSSOP-20 package (JEDEC MO-153, 6.5 mm × 4.4 mm × 1.05 mm body height, 0.65 mm pitch). RoHS-compliant, tape-and-reel packaged (TR suffix).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 19 | Output Enable (1G, 2G) | Active-low enables respective 4-bit inverting buffer groups; high-Z when asserted. |
| 2,4,6,8 / 11,13,15,17 | Data Inputs (1A1–1A4, 2A1–2A4) | Inverting inputs accepting TTL thresholds; tolerate 0–7 V regardless of VCC. |
| 3,5,7,9 / 12,14,16,18 | Data Outputs (1Y1–1Y4, 2Y1–2Y4) | Inverted, 3-state outputs with ±8 mA drive; high-impedance when G = HIGH. |
| 10 | GND | Reference ground for all I/O and internal logic; decoupling capacitor required near pin. |
| 20 | VCC | Positive supply (4.5–5.5 V); must be bypassed with 100 nF ceramic capacitor to GND. |
Key Features
| Feature | Design Value |
|---|---|
| Inverted 3-State Output Architecture | Two independent 4-bit groups with separate enables (1G/2G), reducing bus contention risk in multiplexed memory systems. |
| Input Voltage Tolerance | Accepts −0.5 V to +7.0 V on all inputs - eliminates need for external clamping diodes in mixed-supply backplanes. |
| Symmetrical Output Drive | |IOH| = |IOL| ≥ 8 mA - ensures matched rise/fall times and predictable timing margins in terminated buses. |
| Power-Down Protection | All I/Os remain high-impedance and non-latching when VCC = 0 - prevents back-driving of powered subsystems during hot-swap. |
| Low Dynamic Noise | VOLP ≤ 0.9 V (CL = 50 pF) - minimizes ground bounce in dense PCB layouts with shared return paths. |
Applications
| Memory Address Buffering | Industrial PLC Backplane Interface |
|---|---|
Use Scenario: Isolating CPU address bus from multiple memory banks in embedded controllers. IC Role / Device Role / Timing Role: Inverting 3-state buffer providing direction-controlled, noise-immune address signal routing with precise enable timing. Use Value: Prevents bus contention during memory bank switching; supports 5.4 ns propagation delay for sub-200 MHz clock domains. | Use Scenario: Interfacing 5 V microcontroller I/O to distributed I/O modules over long backplane traces. IC Role / Device Role / Timing Role: Level-tolerant bus driver translating between 5 V logic and isolated field-side circuits with ±8 mA drive capability. Use Value: Eliminates external voltage translators; 7 V input tolerance withstands induced transients on industrial backplanes. |
| Legacy System Bus Extender | Test Equipment Signal Conditioning |
Use Scenario: Extending TTL-compatible data bus length in retro-computing or instrumentation upgrades. IC Role / Device Role / Timing Role: Low-skew inverting repeater with matched tPLH/tPHL ensuring deterministic setup/hold timing across extended traces. Use Value: Compensates for trace capacitance-induced delay; 19 pF CPD enables accurate ICC(opr) estimation for thermal design. | Use Scenario: Driving multiple DUT inputs simultaneously in automated test fixtures with strict noise limits. IC Role / Device Role / Timing Role: Controlled-edge, low-VOLP buffer isolating tester logic from DUT loading and ground bounce coupling. Use Value: Reduces measurement uncertainty via <0.9 V dynamic ground noise; 2 kV ESD rating protects fixture reliability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal inverting bus buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74VHCT240PW | TSSOP-20, identical AC/DC specs, TI-branded; same 5.4 ns tPD, ±8 mA drive, 4 µA ICC. | No functional difference; pin- and logic-compatible drop-in replacement with identical thermal profile. | Select for multi-source procurement or TI-aligned BOMs; verify reel packaging compatibility (TI uses different tape width). |
| 74LCX240MTCX | Lower VCC range (2.0–3.6 V), 3.3 V optimized; tPD = 5.2 ns, but only rated to 3.6 V - not 5 V tolerant. | Requires level-shifting for 5 V systems; unsuitable for direct TTL interface without external circuitry. | Choose only for native 3.3 V designs; avoid in mixed-voltage or legacy 5 V environments. |
Compared with SN74VHCT240PW and 74LCX240MTCX, the 74VHCT240ATTR uniquely combines 5 V TTL compatibility, 7 V input tolerance, and industrial temperature support (−55°C to +125°C), making it optimal for ruggedized 5 V bus isolation where voltage margin and ESD resilience are critical.
Availability
74VHCT240ATTR is available at Aetrix Electronics and suitable for memory address buffering, industrial PLC backplane interfaces, legacy system bus extension, and test equipment signal conditioning requiring stable component supply and long-term lifecycle assurance.
Supply support for 74VHCT240ATTR 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, specializing in automotive, industrial, and power management ICs with strong analog and mixed-signal IP.
The VHCT logic family targets high-speed, low-power 5 V CMOS applications requiring TTL compatibility and enhanced robustness-designed specifically for industrial control, telecom infrastructure, and legacy system upgrades.
FAQ
Can 74VHCT240ATTR operate with VCC = 3.3 V?
No. The 74VHCT240ATTR is specified only for 4.5–5.5 V operation. At 3.3 V, VIH/VIL thresholds are not met, and output drive falls below specification. For 3.3 V systems, use 74LVC240 or 74ALVC240 instead.
What is the maximum capacitive load this device can drive reliably?
It is characterized up to 50 pF (see AC specs), with tPD increasing from 5.4 ns (15 pF) to 5.9 ns (50 pF). For loads >50 pF, add series termination or reduce edge rate; layout-dependent trace capacitance must be included in total CL.
Does the device support hot-swap insertion when VCC is off?
Yes. Power-down protection ensures all inputs and outputs enter high-impedance state with no latch-up risk when VCC = 0 V, and inputs tolerate −0.5 V to +7.0 V - enabling safe hot-plug into live backplanes.
How does the 74VHCT240ATTR differ from the standard 74HCT240?
The VHCT version offers lower ICC (4 µA vs. 20 µA typical), improved latch-up immunity, tighter propagation delay matching (tPLH ≈ tPHL), and enhanced ESD protection (2 kV HBM vs. 2 kV typical for HCT), while retaining full pin and function compatibility.
74VHCT240ATTR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- 74VHCT
- Package/Case:
- 20-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- 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:
- 4.5V ~ 5.5V
- Operating Temperature:
- -55°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-TSSOP
74VHCT240ATTR FAQ
1.How can I place an order for 74VHCT240ATTR through Aetrix?
Please submit a Request for Quotation (RFQ) for 74VHCT240ATTR 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 74VHCT240ATTR reliable?
The price and inventory of 74VHCT240ATTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74VHCT240ATTR is usually 5 days.
3.What payment methods are accepted for 74VHCT240ATTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74VHCT240ATTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74VHCT240ATTR?
74VHCT240ATTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74VHCT240ATTR 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 74VHCT240ATTR?
For technical support, including 74VHCT240ATTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74VHCT240ATTR requirements.
6.How does Aetrix verify that 74VHCT240ATTR is sourced from the original manufacturer or authorized distributors?
All 74VHCT240ATTR 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 74VHCT240ATTR meets industry standards.
7.What is the process for return or replacement of 74VHCT240ATTR?
All 74VHCT240ATTR units undergo pre-shipment inspection (PSI). If there is an issue with 74VHCT240ATTR, 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 74VHCT240ATTR part is unused and in its original packaging.
Return procedure for 74VHCT240ATTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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