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onsemi 74LVQ245SCX
- Part No.:
- 74LVQ245SCX
- Manufacturer:
- onsemi
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
74LVQ245SCX.pdf
- Description:
- IC TXRX NON-INVERT 3.6V 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,384
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Product details
Overview
74LVQ245SCX from Fairchild Semiconductor is a low-voltage octal bidirectional transceiver with 3-STATE outputs, designed for 3.3V bus interface applications. It features ±12 mA drive strength at both A and B ports, 2.0–3.6 V supply range, −40°C to +85°C operating temperature, and guaranteed incident-wave switching into 75Ω transmission lines.
For engineers reviewing the 74LVQ245SCX datasheet, pinout, applications, or equivalent options, key selection criteria include direction control via T/R input, output enable (OE) logic, simultaneous switching noise performance, ESD immunity (≥4 kV), and SOIC JEDEC MS-013 package compatibility.
Technical Context
The 74LVQ245SCX implements a non-inverting bidirectional buffer architecture with independent OE and T/R control inputs. Data flow direction is determined solely by the active-HIGH T/R signal: HIGH enables A→B transfer, LOW enables B→A transfer.
Its 3-STATE outputs support high-impedance isolation when OE is HIGH, and it guarantees dynamic threshold performance and simultaneous switching noise levels per JEDEC standards. The device uses patented EMI reduction circuitry and exhibits improved latch-up immunity per absolute maximum ratings.
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 2.0 V minimum logic thresholds |
| Drive Strength | ±12 mA - sufficient to drive standard 50 Ω terminated lines or multiple CMOS loads |
| Propagation Delay | 7.5 ns typ @ 3.3 V - supports >100 MHz bus timing in short trace configurations |
| ESD Immunity | ≥4 kV HBM - meets industrial I/O robustness requirements without external protection |
| Operating Temperature | −40°C to +85°C - qualified for extended industrial ambient environments |
| Input Thresholds | VIL = 0.8 V, VIH = 2.0 V @ VCC = 3.0 V - ensures reliable TTL/CMOS-level compatibility |
| Dynamic Switching | Guaranteed into 75 Ω - validated for incident-wave switching on controlled-impedance PCB traces |
Pinout & Package
74LVQ245SCX is packaged in a 20-lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" wide (Package Number M20B). Pin spacing is 0.050", body width 0.300", and lead count matches standard 20-pin SOIC footprints.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (OE) | Output Enable Input | Active-HIGH global disable: drives all A/B ports to HIGH-Z when HIGH |
| 2 (A0) | Port A Bidirectional I/O | Non-inverting data path terminal; functions as input or 3-STATE output depending on T/R state |
| 3 (A1) | Port A Bidirectional I/O | Same role as A0; one of eight matched A-side terminals |
| 19 (B7) | Port B Bidirectional I/O | Most significant B-side terminal; electrically identical to B0–B6 |
| 20 (T/R) | Transmit/Receive Control | Active-HIGH selects A→B direction; active-LOW selects B→A direction |
Key Features
| Feature | Design Value |
|---|---|
| EMI Reduction Circuitry | Patented internal slew-rate control reduces radiated emissions during edge transitions |
| Latch-Up Immunity | Enhanced process design prevents destructive latch-up under transient overvoltage conditions |
| Simultaneous Switching Noise Control | Guaranteed noise margin maintained when up to eight outputs switch concurrently |
| 75Ω Transmission Line Drive | Validated incident-wave switching behavior enables direct connection to impedance-controlled PCB traces |
| Low-Voltage Operation | Full functionality at 2.0 V supply supports battery-backed or ultra-low-power system modes |
Applications
| Industrial PLC Backplane Interface | Embedded Microcontroller Bus Extension |
|---|---|
Use Scenario: Isolating and level-shifting between CPU bus and modular I/O expansion slots in programmable logic controllers. IC Role / Device Role / Timing Role: Bidirectional data bridge enabling read/write access across voltage-isolated domains with direction control synchronized to address decode. Use Value: Eliminates need for discrete level shifters and direction logic; 12 mA drive sustains signal integrity across 10 cm backplane traces. | Use Scenario: Extending 8-bit parallel data paths between an MCU and peripheral ASICs or memory-mapped peripherals. IC Role / Device Role / Timing Role: Octal transceiver managing data flow direction under software control via T/R and OE pins. Use Value: Enables flexible bus arbitration with minimal GPIO overhead; 7.5 ns propagation delay supports 10+ MHz synchronous transfers. |
| Test Equipment Digital I/O Module | Legacy System Interfacing Adapter |
Use Scenario: Providing configurable digital stimulus and response channels in automated test equipment rack modules. IC Role / Device Role / Timing Role: Reconfigurable I/O buffer supporting both sourcing and sinking modes per channel pair under firmware control. Use Value: Single-device solution replaces dual unidirectional buffers; 4 kV ESD rating protects against operator-induced discharge events. | Use Scenario: Bridging 3.3 V FPGA I/O banks to legacy 5 V peripheral interfaces using resistor-based level translation. IC Role / Device Role / Timing Role: Low-voltage transceiver acting as intermediate voltage domain translator with direction gating. Use Value: Reduces component count versus discrete MOSFET translators; guaranteed 75Ω drive simplifies termination design. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 74LVC245APW,118 | Lower ICC (2 µA typ), higher speed (tPD = 5.6 ns), but only 2.7–3.6 V operation and no 75Ω incident-wave guarantee | Preferred for ultra-low-quiescent designs where EMI control is secondary to speed | Select when minimizing static power dominates over transmission-line integrity requirements |
| SN74LVCH245AQPWRQ1 | Automotive-grade (−40°C to +125°C), integrated bus-hold resistors, same 2.0–3.6 V range and 12 mA drive | Required for AEC-Q100 qualified automotive body electronics or infotainment interfaces | Choose for automotive deployments needing extended temperature range and built-in input stabilization |
Compared with 74LVQ245SCX, the 74LVC245APW offers faster propagation but sacrifices EMI control and transmission-line validation, while the SN74LVCH245AQPWRQ1 adds automotive qualification and bus-hold at the cost of higher unit price and no EMI patent implementation.
Availability
74LVQ245SCX is available at Aetrix Electronics and suitable for industrial PLC backplanes, embedded microcontroller bus extensions, and test equipment digital I/O modules requiring stable component supply and long-term obsolescence management.
Supply support for 74LVQ245SCX 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 mixed-signal IC manufacturer acquired by ON Semiconductor in 2016, known for high-reliability logic, power, and interface solutions.
The 74LVQ245SCX belongs to Fairchild's LVQ low-voltage logic family, engineered specifically for noise-sensitive 3.3 V bus interfacing in industrial and instrumentation systems where EMI control and transmission-line integrity are critical.
FAQ
What is the recommended supply voltage range for the 74LVQ245SCX?
The 74LVQ245SCX operates reliably across 2.0 V to 3.6 V supply voltage. This range ensures compatibility with 3.3 V systems while allowing marginal operation down to 2.0 V for brown-out tolerance or low-power sleep modes. Operation outside this range risks undefined logic states or damage per absolute maximum ratings.
How does the T/R pin control data direction in the 74LVQ245SCX?
In the 74LVQ245SCX, the T/R pin is an active-HIGH control: when HIGH, data flows from A ports to B ports; when LOW, data flows from B ports to A ports. This single-pin direction control eliminates the need for separate transmit/receive enable logic, simplifying bus arbitration in full-duplex or time-multiplexed interfaces.
Does the 74LVQ245SCX support hot insertion or live bus swapping?
The 74LVQ245SCX is not rated for hot insertion. Its absolute maximum ratings specify that unused inputs must be held HIGH or LOW-not floated-and no current-limiting or precharge circuitry is integrated. For live-swappable backplanes, external protection (e.g., series resistors, TVS diodes) and careful sequencing of OE/T/R assertion are required before connecting.
What is the significance of the "75Ω incident wave switching" specification for the 74LVQ245SCX?
The 75Ω incident wave switching guarantee means the 74LVQ245SCX has been characterized to drive controlled-impedance transmission lines without reflection-induced ringing or overshoot during initial edge propagation. This allows direct connection to 75Ω PCB traces-common in video, instrumentation, and high-speed digital interconnects-without external termination resistors.
Can the 74LVQ245SCX replace older 5 V transceivers like the 74LS245 in existing designs?
No, the 74LVQ245SCX is not a drop-in replacement for 5 V devices such as the 74LS245. It requires 3.3 V supply and has different input thresholds (VIH = 2.0 V, VIL = 0.8 V), making it incompatible with 5 V logic levels without level translation. Attempting direct substitution may cause logic misreads or excessive current draw.
74LVQ245SCX 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:
- Transceiver, Non-Inverting
- Number of Elements:
- 1
- Number of Bits per Element:
- 8
- 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
74LVQ245SCX FAQ
1.How can I place an order for 74LVQ245SCX through Aetrix?
Please submit a Request for Quotation (RFQ) for 74LVQ245SCX 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 74LVQ245SCX reliable?
The price and inventory of 74LVQ245SCX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74LVQ245SCX is usually 5 days.
3.What payment methods are accepted for 74LVQ245SCX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74LVQ245SCX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74LVQ245SCX?
74LVQ245SCX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74LVQ245SCX 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 74LVQ245SCX?
For technical support, including 74LVQ245SCX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74LVQ245SCX requirements.
6.How does Aetrix verify that 74LVQ245SCX is sourced from the original manufacturer or authorized distributors?
All 74LVQ245SCX 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 74LVQ245SCX meets industry standards.
7.What is the process for return or replacement of 74LVQ245SCX?
All 74LVQ245SCX units undergo pre-shipment inspection (PSI). If there is an issue with 74LVQ245SCX, 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 74LVQ245SCX part is unused and in its original packaging.
Return procedure for 74LVQ245SCX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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