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onsemi 74ACTQ240QSCX
- Part No.:
- 74ACTQ240QSCX
- Manufacturer:
- onsemi
- Package:
- 20-LSSOP (0.154", 3.90mm Width)
- Datasheet:
-
74ACTQ240QSCX.pdf
- Description:
- IC BUFF INVERT 5.5V 20QSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,754
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Product details
Overview
74ACTQ240QSCX from Fairchild Semiconductor is an inverting octal buffer/line driver with 3-STATE outputs, designed for memory address driving and bus-oriented transmission in high-density PCBs. It operates at 4.5V–5.5V supply, delivers ±24mA output drive, guarantees ≤1.0ns output-to-output skew at 5V, and features Quiet Series™ technology for controlled dynamic noise.
For engineers reviewing the 74ACTQ240QSCX datasheet, pinout, applications, or equivalent options, this device is selected for low-noise bus interfacing, TTL-compatible memory address buffering, and applications requiring guaranteed simultaneous switching performance and latch-up immunity.
Technical Context
The 74ACTQ240QSCX implements dual 4-bit inverting buffers with independent 3-STATE enable controls (OE1/OE2), each enabling four outputs. Its Quiet Series™ architecture integrates GTO™ output control and undershoot correction alongside a split ground bus to suppress simultaneous switching noise.
It supports guaranteed dynamic input thresholds (VIHD = 2.2V, VILD = 0.8V at 5V), delivers quiet output voltage excursions (VOLP ≤ 1.5V, VOLV ≥ –1.2V), and maintains AC performance across –40°C to +85°C with propagation delays as low as 1.5ns (tPHL/tPLH) and disable times down to 1.0ns (tPHZ/tPLZ).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5V to 5.5V - Ensures compatibility with standard 5V TTL and CMOS systems without level-shifting. |
| Output Drive | ±24mA - Sufficient to directly drive 50pF loads at 1MHz while maintaining VIH/VIL margins. |
| Propagation Delay | 1.5ns (min), 7.5ns (max) at 5V - Enables high-speed address or clock distribution with tight timing budgets. |
| Output Skew | ≤1.0ns - Guarantees synchronized switching across all eight outputs, critical for bus integrity. |
| 3-STATE Leakage | ±2.5µA max - Minimizes bus leakage current when outputs are disabled, preserving signal integrity. |
| Dynamic Input Thresholds | VIHD = 2.2V, VILD = 0.8V at 5V - Provides robust noise immunity against ground bounce and crosstalk. |
| Quiet Output Noise | VOLP ≤ 1.5V, VOLV ≥ –1.2V - Limits transient undershoot/overshoot during switching to prevent false triggering. |
Pinout & Package
74ACTQ240QSCX is housed in a 20-lead Quarter Size Outline Package (QSOP), JEDEC MO-137 compliant, 0.150" wide, with 0.65mm lead pitch - optimized for high-density surface-mount layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 4, 5, 9, 10, 12, 13 | Inputs (I0–I7) | Inverting data inputs; logic HIGH produces LOW output when enabled. |
| 3, 5, 7, 9, 11, 13, 15, 17 | Outputs (O0–O7) | Inverting buffered outputs; tri-stated when corresponding OE is HIGH. |
| 6, 19 | 3-STATE Enable Inputs (OE1, OE2) | Active-LOW enables; OE1 controls O0–O3, OE2 controls O4–O7 - enables partial bus gating. |
| 10 | GND | Power ground reference for all I/O and internal circuitry. |
| 20 | VCC | Positive supply rail (4.5V–5.5V); internally decoupled via split ground bus for noise suppression. |
Key Features
| Feature | Design Value |
|---|---|
| Quiet Series™ Technology | Integrates GTO™ output control and undershoot correction to limit dynamic VOL/VOLP transients during switching. |
| Split Ground Bus Architecture | Reduces simultaneous switching noise by isolating digital and analog return paths within the die. |
| Guaranteed Pin-to-Pin Skew | ≤1.0ns across all outputs ensures deterministic timing for parallel bus interfaces. |
| Improved Latch-Up Immunity | Withstands ±300mA DC latch-up current - enhances reliability in noisy industrial environments. |
| Reduced ICC and IOZ | Quiescent supply current ≤40µA and 3-STATE leakage ≤±2.5µA minimize standby power and bus loading. |
Applications
| Memory Address Buffering | Bus Transceiver Interface |
|---|---|
|
Use Scenario: Driving 16-bit address buses between microcontrollers and SRAM/ROM in embedded control systems. IC Role / Device Role / Timing Role: Inverting octal buffer providing level translation, fanout expansion, and noise-suppressed address latching. Use Value: Guaranteed ≤1.0ns skew prevents address setup/hold violations; ±24mA drive sustains signal integrity across 6-inch PCB traces. |
Use Scenario: Bidirectional data bus isolation between CPU and peripheral ICs in industrial PLC backplanes. IC Role / Device Role / Timing Role: 3-STATE line driver enabling time-multiplexed read/write cycles with precise enable timing control. Use Value: Independent OE1/OE2 pins allow staggered enable sequencing to reduce peak current draw and ground bounce. |
| High-Density Clock Distribution | Noise-Sensitive Sensor Interface |
|
Use Scenario: Distributing system clock signals to multiple synchronous peripherals on space-constrained PCBs. IC Role / Device Role / Timing Role: Low-skew inverting buffer delivering clean, synchronized clock edges with minimal jitter accumulation. Use Value: Quiet Series™ noise suppression prevents clock edge distortion that could degrade timing margins in high-speed ADCs or FPGAs. |
Use Scenario: Isolating analog sensor front-end signals from noisy digital domains in medical instrumentation. IC Role / Device Role / Timing Role: Controlled-slew buffer acting as a digital barrier between sensor ADC interface logic and main processor bus. Use Value: VOLP ≤ 1.5V and VOLV ≥ –1.2V ensure switching transients remain outside analog reference voltage windows. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal inverting buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 74ACT240SCX | Lacks Quiet Series™ noise suppression; higher VOLP (up to 2.0V) and no guaranteed skew spec. | Suitable only in non-critical, low-noise environments where simultaneous switching is minimal. | Select when cost is prioritized over dynamic noise control and skew guarantees. |
| SN74ACT240DWR | TI part with identical logic function but different AC specs: tPHL/tPLH = 6.5ns (max), skew not guaranteed. | Acceptable for general-purpose buffering where timing margin >3ns is available. | Choose when sourcing from TI's authorized channel is required and full Quiet Series™ compliance is not mandatory. |
Compared with 74ACTQ240QSCX, the 74ACT240SCX offers lower cost but sacrifices guaranteed skew and dynamic noise control, while the SN74ACT240DWR provides comparable DC drive but lacks the Quiet Series™ architecture needed for high-integrity bus applications.
Availability
74ACTQ240QSCX is available at Aetrix Electronics and suitable for memory address buffering, industrial bus interfacing, and high-density clock distribution requiring stable component supply and long-term obsolescence management.
Supply support for 74ACTQ240QSCX 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
Fairchild Semiconductor was a leading designer of high-performance analog and mixed-signal ICs, acquired by ON Semiconductor in 2016; its legacy logic portfolio remains widely deployed in industrial and automotive systems.
The 74ACTQ240QSCX belongs to the Quiet Series™ ACT family, engineered specifically for noise-sensitive, high-pin-count digital interfaces where simultaneous switching noise and timing skew must be rigorously controlled.
FAQ
What is the operating temperature range for the 74ACTQ240QSCX?
The 74ACTQ240QSCX is rated for industrial operation from –40°C to +85°C. This range is validated across all DC and AC specifications including propagation delay, output drive, and dynamic input thresholds, ensuring reliable performance in embedded control and automation equipment where ambient temperatures fluctuate significantly.
Does the 74ACTQ240QSCX support 3.3V logic levels?
No, the 74ACTQ240QSCX is specified only for 4.5V to 5.5V supply operation and does not guarantee functionality at 3.3V. Its input thresholds (VIH = 2.0V min, VIL = 0.8V max at 5V) and output drive characteristics are optimized for 5V TTL-compatible systems; use of 3.3V supplies may result in undefined logic states or degraded noise immunity.
How are the 3-STATE enable inputs configured on the 74ACTQ240QSCX?
The 74ACTQ240QSCX has two active-LOW 3-STATE enable inputs: OE1 (Pin 6) controls outputs O0–O3, and OE2 (Pin 19) controls outputs O4–O7. When either OE is HIGH, its associated four outputs enter high-impedance state; both OEs must be LOW to activate all eight outputs. This allows selective bus segmentation without external logic.
What package type is used for the 74ACTQ240QSCX?
The 74ACTQ240QSCX uses a 20-lead Quarter Size Outline Package (QSOP), JEDEC MO-137 compliant, 0.150" wide with 0.65mm lead pitch. This compact surface-mount package supports high-density PCB layouts while maintaining thermal and electrical performance consistent with the SOIC and SOP variants in the same family.
Is the 74ACTQ240QSCX pin-compatible with standard 74ACT240 devices?
Yes, the 74ACTQ240QSCX shares identical pinout and footprint with standard 74ACT240 variants in QSOP (MQA20) packaging, including matching VCC (Pin 20), GND (Pin 10), and I/O assignments. However, it adds Quiet Series™ circuitry internally - no PCB changes are required for drop-in replacement where noise and skew control are needed.
74ACTQ240QSCX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- 74ACTQ
- Package/Case:
- 20-LSSOP (0.154", 3.90mm 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:
- 24mA, 24mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-QSOP
74ACTQ240QSCX FAQ
1.How can I place an order for 74ACTQ240QSCX through Aetrix?
Please submit a Request for Quotation (RFQ) for 74ACTQ240QSCX 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 74ACTQ240QSCX reliable?
The price and inventory of 74ACTQ240QSCX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74ACTQ240QSCX is usually 5 days.
3.What payment methods are accepted for 74ACTQ240QSCX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74ACTQ240QSCX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74ACTQ240QSCX?
74ACTQ240QSCX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74ACTQ240QSCX 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 74ACTQ240QSCX?
For technical support, including 74ACTQ240QSCX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74ACTQ240QSCX requirements.
6.How does Aetrix verify that 74ACTQ240QSCX is sourced from the original manufacturer or authorized distributors?
All 74ACTQ240QSCX 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 74ACTQ240QSCX meets industry standards.
7.What is the process for return or replacement of 74ACTQ240QSCX?
All 74ACTQ240QSCX units undergo pre-shipment inspection (PSI). If there is an issue with 74ACTQ240QSCX, 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 74ACTQ240QSCX part is unused and in its original packaging.
Return procedure for 74ACTQ240QSCX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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