My Inquiry
My Account
onsemi 74LVQ240QSCX
- Part No.:
- 74LVQ240QSCX
- Manufacturer:
- onsemi
- Package:
- 20-LSSOP (0.154", 3.90mm Width)
- Datasheet:
-
74LVQ240QSCX.pdf
- Description:
- IC BUFFER INVERT 3.6V 20QSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,476
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
74LVQ240QSCX from Fairchild Semiconductor is an inverting octal buffer/line driver with dual 3-STATE outputs, operating at 2.0–3.6 V supply, featuring 8.4 ns max propagation delay (VCC = 2.7 V), ±12 mA output drive, and guaranteed incident-wave switching into 75 Ω transmission lines - used in memory address buffering and clock distribution on dense PCBs.
For engineers reviewing the 74LVQ240QSCX datasheet, pinout, applications, or equivalent options, key selection considerations include simultaneous switching noise control, EMI-reduction circuitry, 3.3 V logic compatibility, and QSOP-20 package footprint for space-constrained bus interface designs.
Technical Context
The 74LVQ240QSCX implements two independent 4-bit inverting buffers, each controlled by a dedicated 3-STATE enable input (OE1/OE2). Its patented EMI reduction circuitry suppresses simultaneous switching noise during high-speed transitions.
It guarantees dynamic threshold performance and incident-wave switching into 75 Ω loads across −40°C to +85°C, with input edge rate tolerance ≥125 mV/ns (VCC = 3.0 V) and latch-up immunity exceeding ±300 mA per I/O.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 2.0 V to 3.6 V - compatible with 3.3 V systems and tolerant of 2.5 V rail variations |
| Propagation Delay (tPHL/tPLH) | 7.0 ns typ / 10.5 ns max @ VCC = 3.3 V, CL = 50 pF - enables sub-100 MHz bus timing margins |
| Output Drive | ±12 mA - sufficient to drive standard TTL loads and short PCB traces without external termination |
| 3-STATE Leakage | ±2.5 µA max - ensures low standby current when outputs disabled |
| Input Thresholds (VIH/VIL) | 2.0 V min / 0.8 V max @ VCC = 3.0 V - provides robust noise margin against 3.3 V CMOS logic |
| Dynamic Switching | Guaranteed into 75 Ω - supports direct connection to controlled-impedance clock or data lines |
Pinout & Package
74LVQ240QSCX is housed in a 20-lead Quarter Size Outline Package (QSOP), JEDEC MO-137 compliant, 0.150" wide, with 0.65 mm lead pitch and gull-wing terminations.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 19 | OE1, OE2 | Active-low 3-STATE enable inputs - independently disable top/bottom 4-output groups |
| 2–5, 11–14 | I0–I3, I4–I7 | Inverting data inputs - each drives corresponding inverted output |
| 6–9, 15–18 | O0–O3, O4–O7 | Inverting 3-STATE outputs - high-impedance when respective OE is HIGH |
| 10, 20 | GND, VCC | Power supply terminals - decoupling required within 1 cm of pins for noise control |
Key Features
| Feature | Design Value |
|---|---|
| EMI Reduction Circuitry | Patented slew-rate control minimizes radiated emissions during simultaneous output switching |
| Simultaneous Switching Noise Control | Guaranteed noise level under worst-case 8-output switching - critical for signal integrity in dense layouts |
| 75 Ω Transmission Line Drive | Validated incident-wave switching into 75 Ω - eliminates need for external series termination in clock distribution |
| ESD Immunity | ≥4 kV HBM - meets industrial handling requirements without additional protection circuitry |
Applications
| Memory Address Buffering | Clock Distribution Network |
|---|---|
Use Scenario: Driving address lines from a microcontroller to multiple SRAM or Flash devices on a shared bus. IC Role / Device Role / Timing Role: Inverting octal buffer isolating controller outputs while providing fanout and noise suppression. Use Value: Enables reliable 3.3 V address decoding with <10.5 ns delay and simultaneous 8-bit switching without ground bounce. | Use Scenario: Distributing a system clock to multiple synchronous peripherals (e.g., ADC, DAC, FPGA logic blocks). IC Role / Device Role / Timing Role: Low-skew, low-noise clock driver with 3-STATE capability for dynamic clock gating. Use Value: Delivers clean, impedance-matched clock edges into 75 Ω traces - reducing jitter and reflections in timing-critical paths. |
| Bus Transceiver Interface | Low-Power I/O Expansion |
Use Scenario: Bidirectional data bus isolation between processor and peripheral modules using external direction control. IC Role / Device Role / Timing Role: Octal line driver/receiver with independent OE control enabling half-duplex bus arbitration. Use Value: Provides 12 mA drive strength and fast disable time (≤14 ns tPLZ) for rapid bus turnaround in multiplexed systems. | Use Scenario: Expanding GPIO count on battery-powered IoT nodes where board area and power are constrained. IC Role / Device Role / Timing Role: Low-voltage (2.0–3.6 V) buffer adding 8 programmable I/Os with minimal quiescent current (40 µA max ICC). Use Value: Reduces system-level power vs. 5 V equivalents while maintaining full 3.3 V logic compatibility and QSOP-20 compactness. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal inverting buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 74LVC240PW,118 | Non-inverting inputs; 3.3 V only (1.65–3.6 V); slightly faster (6.7 ns typ tPD) | Lacks guaranteed 75 Ω incident-wave drive; no EMI reduction circuitry specified | Preferred when non-inverting logic is acceptable and EMI constraints are less stringent |
| SN74LV240APWR | Same inverting function; identical VCC range; higher output drive (±16 mA); no EMI circuitry | Higher drive may increase crosstalk; lacks simultaneous switching noise guarantee | Chosen when stronger drive is needed and board layout allows added noise mitigation |
Compared with 74LVQ240QSCX, the 74LVC240PW,118 offers speed and voltage flexibility but omits EMI control and 75 Ω drive assurance, while SN74LV240APWR delivers higher current at the cost of verified noise performance - making 74LVQ240QSCX optimal for noise-sensitive, impedance-controlled 3.3 V bus interfaces.
Availability
74LVQ240QSCX is available at Aetrix Electronics and suitable for memory address buffering, clock distribution networks, and bus transceiver interfaces requiring stable component supply, long-term industrial availability, and consistent QSOP-20 packaging.
Supply support for 74LVQ240QSCX 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 discrete semiconductor manufacturer, acquired by ON Semiconductor in 2016; known for high-reliability logic, power, and interface solutions.
The 74LVQ240QSCX belongs to Fairchild's LVQ low-voltage logic family, engineered specifically for noise-critical 3.3 V digital systems demanding EMI control, transmission-line compatibility, and high-density PCB integration.
FAQ
What is the function of OE1 and OE2 on the 74LVQ240QSCX?
The 74LVQ240QSCX features two independent active-low 3-STATE enable inputs: OE1 controls outputs O0–O3, and OE2 controls O4–O7. When either OE is HIGH, its associated four outputs enter high-impedance state; when LOW, the corresponding inverting buffer is active. This allows selective bus partitioning without external logic.
Does the 74LVQ240QSCX support 2.5 V operation?
Yes, the 74LVQ240QSCX operates over 2.0 V to 3.6 V, fully supporting 2.5 V nominal supplies. Input thresholds scale with VCC, and DC/AC parameters including propagation delay and drive strength are characterized across this range - confirmed in the Recommended Operating Conditions table.
Is the 74LVQ240QSCX pin-compatible with standard 74LS240 or 74HC240 packages?
No - the 74LVQ240QSCX uses a QSOP-20 package (MQA20), whereas 74LS240 and 74HC240 typically use DIP-20 or SOIC-20. Pin functions match the industry-standard 240 logic assignment (dual 4-bit inverting buffers with separate OE), but physical dimensions and lead pitch differ; PCB layout must accommodate QSOP-20 footprint.
What does "guaranteed incident wave switching into 75 Ω" mean for the 74LVQ240QSCX?
This specification means the 74LVQ240QSCX output drivers are validated to cleanly launch signals onto 75 Ω transmission lines without overshoot or reflection-induced timing errors - critical for clock and high-speed data routing. It reflects controlled edge rates and output impedance matching, eliminating need for external series resistors in many cases.
How does the EMI reduction circuitry in the 74LVQ240QSCX work?
The 74LVQ240QSCX integrates patented internal slew-rate control that limits dV/dt on all eight outputs during switching, reducing high-frequency harmonic content and radiated emissions. This is distinct from external RC filtering and is effective even under worst-case simultaneous 8-bit transitions - directly addressing board-level EMI compliance challenges.
74LVQ240QSCX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- 74LVQ
- 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:
- 12mA, 12mA
- Voltage - Supply:
- 2V ~ 3.6V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-QSOP
74LVQ240QSCX FAQ
1.How can I place an order for 74LVQ240QSCX through Aetrix?
Please submit a Request for Quotation (RFQ) for 74LVQ240QSCX 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 74LVQ240QSCX reliable?
The price and inventory of 74LVQ240QSCX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74LVQ240QSCX is usually 5 days.
3.What payment methods are accepted for 74LVQ240QSCX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74LVQ240QSCX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74LVQ240QSCX?
74LVQ240QSCX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74LVQ240QSCX 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 74LVQ240QSCX?
For technical support, including 74LVQ240QSCX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74LVQ240QSCX requirements.
6.How does Aetrix verify that 74LVQ240QSCX is sourced from the original manufacturer or authorized distributors?
All 74LVQ240QSCX 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 74LVQ240QSCX meets industry standards.
7.What is the process for return or replacement of 74LVQ240QSCX?
All 74LVQ240QSCX units undergo pre-shipment inspection (PSI). If there is an issue with 74LVQ240QSCX, 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 74LVQ240QSCX part is unused and in its original packaging.
Return procedure for 74LVQ240QSCX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
74LVQ240QSCX Tags
-
SN74LVC1G17DBVR
Texas Instruments
-
SN74LVC1G07DCKR
Texas Instruments
-
SN74LVC1G17DCKR
Texas Instruments
-
SN74LVC1G07DBVR
Texas Instruments
-
SN74LVC1G125DCKR
Texas Instruments
-
SN74AHCT1G126DBVR
Texas Instruments
-
SN74LVC1G125DBVR
Texas Instruments
-
SN74AHCT1G125DBVR
Texas Instruments
-
SN74LVC2G17DBVR
Texas Instruments
-
SN74LVC2G07DCKR
Texas Instruments
-
SN74LVC1G34DCKR
Texas Instruments
-
SN74LVC2G17DCKR
Texas Instruments
Tech Hub
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
