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onsemi 74LVQ244SCX
- Part No.:
- 74LVQ244SCX
- Manufacturer:
- onsemi
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
74LVQ244SCX.pdf
- Description:
- IC BUF NON-INVERT 3.6V 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,276
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Product details
Overview
74LVQ244SCX from Fairchild Semiconductor is a low-voltage octal buffer/line driver with dual 3-STATE output enables, operating from 2.0V to 3.6V supply, delivering ±12mA drive strength, 9.5ns max propagation delay at 3.3V, and 4kV ESD immunity-used in memory address buffering and bus interface applications on dense PCBs.
For engineers reviewing the 74LVQ244SCX datasheet, pinout, applications, or equivalent options, key selection factors include simultaneous switching noise control, guaranteed incident-wave switching into 75Ω transmission lines, dynamic input threshold compliance (VIHD/VILD), and SOIC JEDEC MS-013 package compatibility.
Technical Context
The 74LVQ244SCX implements dual independent 4-bit buffers (I0–I3/O0–O3 enabled by OE1; I4–I7/O4–O7 enabled by OE2), each with high-impedance 3-STATE outputs controlled by active-low enables. It features patented EMI reduction circuitry and guaranteed dynamic threshold performance across −40°C to +85°C.
Its design supports incident-wave switching on 75Ω transmission lines without termination, meets strict simultaneous switching noise limits, and provides improved latch-up immunity per JEDEC JESD78. Input thresholds are dynamically specified (VIHD = 2.0V min, VILD = 0.8V max at VCC = 3.3V).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 2.0V to 3.6V - compatible with 3.3V logic systems and tolerant of supply variation |
| IO Drive | ±12mA - sufficient for driving terminated transmission lines and multiple CMOS inputs |
| tPLH / tPHL | ≤9.5ns at VCC = 3.3V, CL = 50pF - enables high-speed bus buffering up to ~100MHz data rates |
| VIHD / VILD | 2.0V min / 0.8V max at VCC = 3.3V - ensures reliable logic-level recognition under fast edge rates |
| ESD Rating | ≥4kV HBM - provides robust handling in automated assembly and field environments |
| SSN Guarantee | Specified simultaneous switching noise level - allows dense placement without signal integrity degradation |
| Dynamic Skew | ≤1.5ns (tOSLH/tOSHL) - maintains timing alignment across all eight outputs during parallel switching |
Pinout & Package
74LVQ244SCX is packaged in a 20-lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" wide (Package Number M20B), with standard pin pitch of 0.050" and body width of 7.5mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 19 | VCC | Positive supply rail - must be decoupled locally to suppress switching noise |
| 10 | GND | Ground reference - shared return path for all inputs, outputs, and enables |
| 12, 14, 16, 18 | OE1 | Active-low enable for outputs O0–O3 - controls group-wide 3-STATE behavior |
| 3, 5, 7, 9 | OE2 | Active-low enable for outputs O4–O7 - independent control of second buffer bank |
| 2, 4, 6, 8 | I0–I3 | Data inputs for first buffer group - TTL/CMOS-compatible voltage thresholds |
| 11, 13, 15, 17 | I4–I7 | Data inputs for second buffer group - electrically isolated from first group |
| 19, 20, 1, 11 | O0–O3 | 3-STATE outputs driven by I0–I3 - high-impedance when OE1 = HIGH |
| 12, 13, 14, 15 | O4–O7 | 3-STATE outputs driven by I4–I7 - high-impedance when OE2 = HIGH |
Key Features
| Feature | Design Value |
|---|---|
| EMI Reduction Circuitry | Patented slew-rate control minimizes radiated emissions during output transitions |
| 75Ω Incident-Wave Switching | Guaranteed clean edge launch into unterminated 75Ω traces - eliminates need for point-of-load termination |
| Dynamic Threshold Compliance | VIHD ≥2.0V and VILD ≤0.8V at 3.3V - ensures noise margin against ground bounce and crosstalk |
| Latch-Up Immunity | Improved structure withstands >300mA transient current - enhances system reliability in noisy environments |
| Simultaneous Switching Noise Control | Specified SSN level enables full-octal switching without corrupting adjacent signals |
Applications
| Memory Address Buffering | PCI Bus Transceiver Interface |
|---|---|
Use Scenario: Driving 20-bit address buses between microcontrollers and SRAM/Flash devices on compact PCBs. IC Role / Device Role / Timing Role: Bidirectional address line driver with 3-STATE isolation to prevent bus contention during read/write cycles. Use Value: Enables high-density layout via guaranteed 75Ω incident-wave switching and low simultaneous switching noise. | Use Scenario: Level-shifting and bus isolation between 3.3V PCI controller and peripheral slots. IC Role / Device Role / Timing Role: Unidirectional buffer providing drive strength and timing-controlled enable sequencing for PCI address/data phases. Use Value: Meets PCI timing skew requirements (≤1.5ns) and supports hot-insertion-safe 3-STATE control. |
| Industrial Backplane Driver | Digital I/O Expansion Module |
Use Scenario: Transmitting parallel control signals across 10cm+ backplane traces in PLC I/O racks. IC Role / Device Role / Timing Role: Low-noise line driver with EMI-reduced edges and robust 4kV ESD protection for factory-floor environments. Use Value: Eliminates external termination and reduces board area vs. discrete resistor networks. | Use Scenario: Expanding GPIO count on ARM-based embedded controllers using parallel port expansion. IC Role / Device Role / Timing Role: Octal buffer isolating MCU pins from higher-capacitance peripheral loads (e.g., LED arrays, relays). Use Value: Provides ±12mA sink/source per output - sufficient to drive LEDs directly without external transistors. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal buffer/line driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74LVC244APWR | Lower ICC (1µA typ), wider VCC range (1.65–3.6V), no guaranteed 75Ω incident-wave switching | Suitable for ultra-low-power portable designs but lacks SSN and dynamic threshold guarantees | Prefer 74LVQ244SCX where transmission-line integrity and noise immunity are critical |
| 74ALVC244MTCX | Faster tPLH (2.8ns typ), higher drive (±24mA), no EMI reduction circuitry or 4kV ESD rating | Better for speed-critical interfaces but requires additional layout mitigation for EMI and latch-up | Choose 74LVQ244SCX for industrial-grade robustness over raw speed |
Compared with SN74LVC244APWR and 74ALVC244MTCX, the 74LVQ244SCX uniquely combines EMI reduction, guaranteed 75Ω incident-wave operation, and 4kV ESD in a single SOIC package - making it optimal for noise-sensitive, high-density interconnects where signal fidelity outweighs minimum quiescent current.
Availability
74LVQ244SCX is available at Aetrix Electronics and suitable for memory address buffering, PCI bus interfacing, and industrial backplane driver applications requiring stable component supply and long-term industrial temperature support (−40°C to +85°C).
Supply support for 74LVQ244SCX 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 U.S.-based analog and power IC manufacturer, acquired by ON Semiconductor in 2016; its legacy logic portfolio remains widely deployed in industrial and computing infrastructure.
The 74LVQ244SCX belongs to Fairchild's LVQ low-voltage logic family, engineered specifically for noise-sensitive 3.3V system interconnects demanding EMI control, transmission-line compatibility, and robust operation in harsh electrical environments.
FAQ
What is the maximum recommended supply voltage for the 74LVQ244SCX?
The 74LVQ244SCX has an absolute maximum VCC rating of +7.0V, but its recommended operating range is strictly 2.0V to 3.6V. Operation above 3.6V voids parametric guarantees including VOH/VOL, propagation delay, and ESD immunity. The 74LVQ244SCX is not rated for 5V logic systems - use 74LVT or 74ACT families instead if 5V compatibility is required.
Does the 74LVQ244SCX support true bidirectional data flow?
No, the 74LVQ244SCX is a unidirectional octal buffer: inputs (I0–I7) drive corresponding outputs (O0–O7) only. It lacks internal direction-control logic or bus-transceiver architecture. For bidirectional applications like I²C or UART level-shifting, discrete solutions or dedicated transceivers such as the 74LVC245 are required. The 74LVQ244SCX functions solely as a one-way driver with dual 3-STATE enables.
What does "guaranteed incident wave switching into 75Ω" mean for the 74LVQ244SCX?
This specification means the 74LVQ244SCX can launch clean, non-reflected logic edges onto unterminated 75Ω transmission lines - typical of video or RF interconnects - without requiring external series or parallel termination resistors. It reflects controlled output impedance and edge rate tuning. This capability is verified per Note 5 in the datasheet and applies across the full commercial temperature range, distinguishing the 74LVQ244SCX from standard LVC or ALVC buffers.
Can unused inputs on the 74LVQ244SCX be left floating?
No. Per Note 2 in the datasheet, all unused inputs on the 74LVQ244SCX must be actively tied HIGH or LOW - floating inputs may cause excessive ICC, unpredictable output states, or increased susceptibility to EMI. OE1 and OE2 inputs are especially sensitive: leaving them unconnected risks unintended 3-STATE activation. The 74LVQ244SCX requires explicit biasing of every input pin to ensure stable operation and meet guaranteed AC/DC specifications.
Is the 74LVQ244SCX pin-compatible with other 74-series octal buffers like the 74LS244?
No - the 74LVQ244SCX uses a different pinout than bipolar 74LS244 or even CMOS 74HC244. While both are 20-pin octal buffers, the 74LVQ244SCX assigns OE1 to pins 12/14/16/18 and OE2 to pins 3/5/7/9, whereas 74LS244 uses single OE on pin 1 and 19. Substituting the 74LVQ244SCX into an LS244 layout would cause functional failure. Always verify pin mapping before replacement; the 74LVQ244SCX is not a drop-in upgrade.
74LVQ244SCX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- 74LVQ
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Logic Type:
- Buffer, Non-Inverting
- Number of Elements:
- 2
- Number of Bits per Element:
- 4
- Input Type:
- -
- Output Type:
- 3-State
- Current - Output High, Low:
- 12mA, 12mA
- Voltage - Supply:
- 2V ~ 3.6V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SOIC
74LVQ244SCX FAQ
1.How can I place an order for 74LVQ244SCX through Aetrix?
Please submit a Request for Quotation (RFQ) for 74LVQ244SCX 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 74LVQ244SCX reliable?
The price and inventory of 74LVQ244SCX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74LVQ244SCX is usually 5 days.
3.What payment methods are accepted for 74LVQ244SCX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74LVQ244SCX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74LVQ244SCX?
74LVQ244SCX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74LVQ244SCX 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 74LVQ244SCX?
For technical support, including 74LVQ244SCX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74LVQ244SCX requirements.
6.How does Aetrix verify that 74LVQ244SCX is sourced from the original manufacturer or authorized distributors?
All 74LVQ244SCX 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 74LVQ244SCX meets industry standards.
7.What is the process for return or replacement of 74LVQ244SCX?
All 74LVQ244SCX units undergo pre-shipment inspection (PSI). If there is an issue with 74LVQ244SCX, 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 74LVQ244SCX part is unused and in its original packaging.
Return procedure for 74LVQ244SCX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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