My Inquiry
My Account
onsemi MC74LCX245MELG
- Part No.:
- MC74LCX245MELG
- Manufacturer:
- onsemi
- Package:
- 20-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
MC74LCX245MELG.pdf
- Description:
- IC TXRX NON-INVERT 5.5V 20SOEIAJ
- Quantity:
- Payment:
- Shipping:
Inventory:3,932
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MC74LCX245MELG from onsemi is a low-voltage CMOS octal transceiver with 5 V-tolerant inputs/outputs, non-inverting bidirectional data flow, 1.65–5.5 V supply operation, 24 mA output drive at VCC = 3.0 V, and 3-state control via OE and T/R pins. It serves as a level-shifting bus transceiver in mixed-voltage memory address and data bus systems.
For engineers reviewing the MC74LCX245MELG datasheet, pinout, applications, or equivalent options, key selection criteria include 5 V tolerance with sub-3.3 V VCC, direction-controlled bidirectional I/O, high-impedance TTL-compatible inputs, and QFN20 package thermal performance for compact board layouts.
Technical Context
The MC74LCX245MELG implements a dual-bus, non-inverting transceiver architecture where the T/R input selects data direction (A→B when HIGH, B→A when LOW), while OE enables/disables both ports simultaneously into high-impedance state. Its IOFF specification ensures safe high-Z behavior at VCC = 0 V, supporting live insertion.
It operates across 1.65–5.5 V with guaranteed 5.5 V input voltage tolerance, enabling direct interfacing with legacy 5 V TTL logic without level shifters. Propagation delay is ≤7.0 ns at VCC = 3.0–3.6 V, and output skew is ≤1.0 ns across all eight channels under matched switching conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 1.65 V to 5.5 V - supports single-supply operation across LVTTL, LVCMOS, and mixed-voltage system domains |
| Input Voltage Tolerance | −0.5 V to +6.5 V - allows safe connection to 5 V drivers even when VCC is as low as 1.65 V |
| Output Drive | ±24 mA at VCC = 3.0 V - sufficient to drive standard 50 Ω transmission lines or multiple TTL loads |
| Propagation Delay | ≤7.0 ns (VCC = 3.0–3.6 V) - enables reliable operation in 100+ MHz bus applications with timing margin |
| IOFF Leakage | ≤10 µA at VI = 5.5 V or VO = 5.5 V - prevents back-powering and signal contention during power-down |
| Input Capacitance | 7 pF - minimizes capacitive loading on upstream drivers, preserving signal integrity at high edge rates |
| ESD Rating | >2000 V HBM - meets industrial-grade robustness requirements for handling and assembly |
Pinout & Package
MC74LCX245MELG is packaged in a 20-pin QFN (2.5 mm × 4.5 mm, 0.5 mm pitch, exposed thermal pad), per case 485AA-01. This leadless package delivers low thermal resistance (99 °C/W) and compact footprint ideal for space-constrained embedded designs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 19 | OE (Output Enable) | Active-HIGH control: asserts high-impedance state on both A and B ports when HIGH |
| 2, 18 | T/R (Transmit/Receive) | Direction control: A→B when HIGH, B→A when LOW; defines active data path |
| 3–10 | A0–A7 | Side-A bidirectional I/O: function as inputs or outputs depending on T/R state |
| 11–18 | B0–B7 | Side-B bidirectional I/O: mirror A-side functionality with independent 3-state control |
| 12 | GND | Ground reference for all logic and I/O circuits; connects to exposed thermal pad |
| 20 | VCC | Primary power supply (1.65–5.5 V); powers internal logic and I/O buffers |
Key Features
| Feature | Design Value |
|---|---|
| 5 V-tolerant I/O | Enables direct interface with 5 V TTL logic while operating from 1.65–3.3 V supplies - eliminates external level shifters |
| IOFF protection | Guarantees high-impedance I/O when VCC = 0 V - prevents back-driving and bus contention during hot-swap or partial power-down |
| 24 mA balanced drive | Equal sink/source capability at 3.0 V ensures consistent rise/fall times and noise immunity across bidirectional transitions |
| Low static ICC | ≤10 µA in all three logic states - reduces quiescent power in always-on or battery-backed subsystems |
| Latchup immunity | >100 mA - exceeds JEDEC JESD78 requirements, ensuring robust operation in noisy industrial environments |
Applications
| Memory Address Bus Interface | Multi-Voltage Microcontroller Expansion |
|---|---|
|
Use Scenario: Interfacing a 3.3 V microcontroller's address bus to legacy 5 V SRAM or EPROM devices. IC Role / Device Role: Bidirectional level-shifting transceiver managing address propagation from MCU to memory and status signals back. Use Value: Eliminates discrete level translators; 5 V-tolerant inputs accept memory output signals directly while 3.3 V outputs meet MCU input thresholds. |
Use Scenario: Expanding GPIO count of a 2.5 V SoC by connecting peripheral modules operating at 3.3 V or 5 V. IC Role / Device Role: Configurable bus transceiver enabling data exchange between heterogeneous voltage domains on shared parallel buses. Use Value: Single device handles direction control (T/R) and tristate (OE), reducing PCB complexity versus discrete buffer solutions. |
| Industrial PLC Backplane Interface | Automotive Body Control Module Bus Isolation |
|
Use Scenario: Isolating and translating control signals between 3.3 V logic controllers and 5 V field I/O modules on a DIN-rail mounted PLC backplane. IC Role / Device Role: Robust bidirectional transceiver providing ESD-hardened, latchup-immune communication across voltage-isolated zones. Use Value: >2000 V HBM rating and >100 mA latchup immunity ensure reliability in electrically noisy factory-floor environments. |
Use Scenario: Enabling communication between a 3.3 V body controller MCU and 5 V lighting or sensor modules in AEC-Q100-compliant vehicle subsystems. IC Role / Device Role: Automotive-qualified transceiver (via −Q suffix variants) performing voltage-domain bridging with live-insertion support. Use Value: IOFF behavior prevents back-powering during module replacement; Pb-free, halogen-free construction meets automotive RoHS requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74LVC245APWR | Lower max VCC (3.6 V), no 5 V tolerance above VCC - requires external clamping for 5 V inputs | Best suited for pure 3.3 V systems; not recommended for direct 5 V interface without protection circuitry | Select when operating exclusively within 1.65–3.6 V domain and cost sensitivity outweighs 5 V interface flexibility |
| 74ALVC245PW | Higher speed (tPD ≤ 3.3 ns @ 3.3 V), but only 3.6 V absolute max input - lacks 5 V tolerance guarantee | Preferred for high-speed 3.3 V-only buses where timing margin is critical and voltage translation is handled elsewhere | Choose for sub-5 ns timing-critical paths where 5 V compatibility is unnecessary and layout space permits SOIC/TSSOP |
Compared with SN74LVC245APWR and 74ALVC245PW, MC74LCX245MELG uniquely guarantees 5.5 V input tolerance at VCC < 5.0 V - making it the only option among the three that safely interfaces 5 V peripherals without external components in mixed-voltage designs.
Availability
MC74LCX245MELG is available at Aetrix Electronics and suitable for memory address driving, multi-voltage microcontroller expansion, and industrial PLC backplane interface applications requiring stable component supply and long-term manufacturability.
Supply support for MC74LCX245MELG 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
onsemi (formerly ON Semiconductor) is a global semiconductor supplier focused on energy-efficient innovation for automotive, industrial, cloud, and IoT applications.
The MC74LCX245MELG belongs to the LCX low-voltage CMOS logic family, engineered for robust mixed-voltage interoperability, live insertion, and low-power operation in space-constrained embedded systems.
FAQ
What is the maximum input voltage rating for MC74LCX245MELG?
The MC74LCX245MELG supports DC input voltages from −0.5 V to +6.5 V, with a guaranteed 5.5 V tolerance specified for VI. This allows safe connection to 5 V TTL outputs even when VCC is as low as 1.65 V, eliminating need for external clamping diodes in most mixed-voltage interfaces.
Does MC74LCX245MELG support live insertion?
Yes, MC74LCX245MELG supports live insertion and withdrawal due to its IOFF specification, which guarantees high-impedance I/O states when VCC = 0 V. This prevents back-driving of powered buses during hot-swap events in modular systems like PLC backplanes or server blade architectures.
What package type is used for MC74LCX245MELG?
MC74LCX245MELG uses a 20-pin QFN package (2.5 mm × 4.5 mm, 0.5 mm pitch, exposed thermal pad), designated case 485AA-01. This surface-mount package offers low thermal resistance (99 °C/W) and minimal PCB footprint, ideal for high-density portable and industrial control designs.
How does the T/R pin control data direction in MC74LCX245MELG?
In MC74LCX245MELG, the T/R pin is an active-HIGH direction control: when T/R = HIGH, data flows from A ports to B ports; when T/R = LOW, data flows from B ports to A ports. This bidirectional control operates independently of OE, allowing dynamic bus reversal without disabling outputs.
Is MC74LCX245MELG compliant with automotive standards?
The base MC74LCX245MELG is not automotive-qualified, but onsemi offers the −Q suffix variant (e.g., MC74LCX245DTR2G−Q) which is AEC-Q100 qualified and PPAP capable. That variant shares identical electrical specs and pinout, differing only in traceability, screening, and documentation for automotive use cases.
MC74LCX245MELG Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- 74LCX
- Package/Case:
- 20-SOIC (0.209", 5.30mm 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:
- 24mA, 24mA
- Voltage - Supply:
- 2V ~ 5.5V
- Operating Temperature:
- -55°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOEIAJ-20
MC74LCX245MELG FAQ
1.How can I place an order for MC74LCX245MELG through Aetrix?
Please submit a Request for Quotation (RFQ) for MC74LCX245MELG 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 MC74LCX245MELG reliable?
The price and inventory of MC74LCX245MELG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC74LCX245MELG is usually 5 days.
3.What payment methods are accepted for MC74LCX245MELG?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC74LCX245MELG transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MC74LCX245MELG?
MC74LCX245MELG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MC74LCX245MELG 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 MC74LCX245MELG?
For technical support, including MC74LCX245MELG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC74LCX245MELG requirements.
6.How does Aetrix verify that MC74LCX245MELG is sourced from the original manufacturer or authorized distributors?
All MC74LCX245MELG 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 MC74LCX245MELG meets industry standards.
7.What is the process for return or replacement of MC74LCX245MELG?
All MC74LCX245MELG units undergo pre-shipment inspection (PSI). If there is an issue with MC74LCX245MELG, 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 MC74LCX245MELG part is unused and in its original packaging.
Return procedure for MC74LCX245MELG:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MC74LCX245MELG 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…
