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Home > Products > Integrated Circuits (ICs) > Logic > Buffers, Drivers, Receivers, Transceivers

onsemi MC74VHC125MELG

Name: MC74VHC125MELG
Brand: onsemi
SKU: MC74VHC125MELG
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MC74VHC125MELG

Manufacturer:: onsemi

Category:: Buffers, Drivers, Receivers, Transceivers

Package:: 14-SOIC (0.209", 5.30mm Width)

Datasheet:: MC74VHC125MELG.pdf

Description:: IC BUF NON-INVERT 5.5V SOEIAJ-14

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Product details

Overview

MC74VHC125MELG from onsemi is a quad 3-state bus buffer IC designed for high-speed digital signal routing in 2.0–5.5 V systems. It features four independent A→Y buffers, each with active-high output enable (OE), 3.8 ns typical propagation delay at 5 V, ±25 mA output drive, and full 5.0 V CMOS-level output swing - enabling reliable level translation between 3.3 V logic domains and legacy 5 V buses.

For engineers reviewing the MC74VHC125MELG datasheet, pinout, applications, or equivalent options, this device is selected for bidirectional bus isolation, memory address/data gating, and hot-swap-capable I/O expansion where low quiescent current (4 µA max), high noise immunity (28% V_CC), and input overvoltage tolerance to 5.5 V are critical design requirements.

Technical Context

The MC74VHC125MELG implements four identical non-inverting buffer stages, each with separate 3-state control (OE) and CMOS-compatible inputs. Its internal three-stage architecture delivers balanced t_PLH/t_PHL propagation delays and high noise immunity via robust input threshold design (V_IH = 3.85 V min, V_IL = 1.65 V max at V_CC = 5.5 V).

It supports mixed-voltage interfacing: inputs tolerate up to 5.5 V regardless of V_CC, allowing safe connection to 5 V sources even when powered from 3.3 V; outputs deliver rail-to-rail CMOS swings (V_OH ≥ 4.4 V, V_OL ≤ 0.1 V at I_OL = 4 mA, V_CC = 4.5 V), making it suitable for driving TTL- and CMOS-loaded buses.

Key Specifications

Parameter	Value and Actual Design Meaning
Supply Voltage Range	2.0 V to 5.5 V - enables operation across 3.3 V and 5 V systems without level shifters
Propagation Delay (t_PD)	3.8 ns (typ) at V_CC = 5 V, CL = 15 pF - supports >100 MHz bus toggling with timing margin
Output Drive	±25 mA per pin - sufficient to drive 10 LSTTL loads or 50 pF transmission lines
Input Overvoltage Tolerance	−0.5 V to +6.5 V - permits direct interface to 5 V signals while V_CC = 3.3 V
Quiescent Current (I_CC)	4 µA (max) at TA = 25°C - minimizes standby power in battery-backed or low-power systems
3-State Leakage (I_OZ)	±2.5 µA (max) at V_CC = 5.5 V - ensures clean bus release during tri-state transitions
Noise Immunity	V_NIH = V_NIL = 28% V_CC - rejects >1.4 V noise spikes on 5 V buses

Pinout & Package

TSSOP-14 (Case 948G) package: 4.9 mm × 4.4 mm × 1.2 mm body, 0.65 mm pitch, Pb-free, RoHS compliant.

Pin/Terminal	Circuit Role	Design Meaning
1, 4, 10, 13	A1–A4 (Data Inputs)	Buffer input terminals; accept CMOS-level signals up to 5.5 V independent of V_CC
2, 5, 11, 14	OE1–OE4 (Output Enables)	Active-high 3-state controls; OE = HIGH disables output (high-Z); tolerant to 5.5 V
3, 6, 8, 12	Y1–Y4 (Outputs)	Non-inverting buffered outputs; full rail-to-rail swing, ±25 mA drive capability
7	GND	Ground reference for all logic and I/O; must be low-impedance for noise immunity
14	V_CC	Positive supply (2.0–5.5 V); powers internal logic and output drivers

Key Features

Feature	Design Value
High-speed CMOS performance	t_PD = 3.8 ns typ at 5 V - matches Bipolar Schottky TTL speed with CMOS power efficiency
Input voltage tolerance	Inputs withstand −0.5 V to +6.5 V - eliminates external clamping diodes in mixed-voltage designs
Power-down protection	Inputs remain high-impedance and non-latching when V_CC = 0 V - prevents backfeeding during hot insertion
Latchup immunity	Exceeds 100 mA per JESD78 Class II - ensures robustness against transient-induced latchup
ESD resilience	Human Body Model > 2000 V - reduces handling sensitivity during assembly and test

Applications

Memory Address Bus Isolation	Microcontroller I/O Expansion
Use Scenario: Isolating address lines between a microcontroller and multiple SRAM/Flash devices sharing a common bus. IC Role / Device Role / Timing Role: Quad buffer provides per-line 3-state control to prevent bus contention during memory access arbitration. Use Value: Enables deterministic bus turn-around with 3.8 ns propagation delay and <1.5 ns output skew - critical for synchronous burst transfers.	Use Scenario: Expanding GPIO count of an MCU by connecting parallel peripherals (e.g., LCD, keypad, ADC) via shared data bus. IC Role / Device Role / Timing Role: Acts as bidirectional bus gate; OE signals synchronized to MCU write/read strobes to manage direction and timing. Use Value: Full 5.0 V CMOS output swing drives legacy peripherals directly; 5.5 V-tolerant inputs allow safe connection to 5 V sensors without level shifters.
Hot-Swappable Module Interface	Industrial PLC Backplane Buffering
Use Scenario: Enabling live insertion/removal of I/O modules in programmable logic controllers without disrupting main CPU bus. IC Role / Device Role / Timing Role: Provides controlled bus isolation; OE pins driven by module presence detection to assert high-Z before physical connection. Use Value: Input structures survive V_CC = 0 V conditions; output clamp protection prevents damage during hot-plug transients.	Use Scenario: Buffering fieldbus signals (e.g., Modbus RTU) between noisy industrial sensor networks and isolated controller logic. IC Role / Device Role / Timing Role: Signal integrity conditioner: suppresses ground bounce and crosstalk via balanced drive and 28% V_CC noise margin. Use Value: Low dynamic noise (V_OLP ≤ 0.8 V) and high ESD rating (>2 kV HBM) ensure reliable operation in electrically harsh factory environments.

Memory Address Bus Isolation

Microcontroller I/O Expansion

Use Scenario: Isolating address lines between a microcontroller and multiple SRAM/Flash devices sharing a common bus.

IC Role / Device Role / Timing Role: Quad buffer provides per-line 3-state control to prevent bus contention during memory access arbitration.

Use Value: Enables deterministic bus turn-around with 3.8 ns propagation delay and <1.5 ns output skew - critical for synchronous burst transfers.

Use Scenario: Expanding GPIO count of an MCU by connecting parallel peripherals (e.g., LCD, keypad, ADC) via shared data bus.

IC Role / Device Role / Timing Role: Acts as bidirectional bus gate; OE signals synchronized to MCU write/read strobes to manage direction and timing.

Use Value: Full 5.0 V CMOS output swing drives legacy peripherals directly; 5.5 V-tolerant inputs allow safe connection to 5 V sensors without level shifters.

Hot-Swappable Module Interface

Industrial PLC Backplane Buffering

Use Scenario: Enabling live insertion/removal of I/O modules in programmable logic controllers without disrupting main CPU bus.

IC Role / Device Role / Timing Role: Provides controlled bus isolation; OE pins driven by module presence detection to assert high-Z before physical connection.

Use Value: Input structures survive V_CC = 0 V conditions; output clamp protection prevents damage during hot-plug transients.

Use Scenario: Buffering fieldbus signals (e.g., Modbus RTU) between noisy industrial sensor networks and isolated controller logic.

IC Role / Device Role / Timing Role: Signal integrity conditioner: suppresses ground bounce and crosstalk via balanced drive and 28% V_CC noise margin.

Use Value: Low dynamic noise (V_OLP ≤ 0.8 V) and high ESD rating (>2 kV HBM) ensure reliable operation in electrically harsh factory environments.

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad 3-state buffer applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
SN74LVC125APWR	Lower V_CC range (1.65–3.6 V); 3.3 V only; 3.5 ns t_PD; TTL-compatible inputs	Optimized for modern 3.3 V-only systems; not suitable for 5 V interfacing or mixed-voltage use	Select when operating exclusively at 3.3 V and requiring lowest possible propagation delay
MC74VHCT125ADR2G	TTL-compatible inputs (V_IH = 2.0 V min); otherwise identical pinout, timing, and drive	Preferred for interfacing with legacy 5 V TTL logic families where input thresholds must match 2.0 V	Choose when connecting to standard TTL outputs or when system-level noise margins require tighter VIH/VIL specs

Compared with SN74LVC125APWR and MC74VHCT125ADR2G, the MC74VHC125MELG uniquely supports dual-voltage operation (2.0–5.5 V) with 5.5 V-tolerant inputs - making it the only option among the three capable of seamless 3.3 V ↔ 5 V level translation without external components.

Availability

MC74VHC125MELG is available at Aetrix Electronics and suitable for memory subsystems, microcontroller peripheral expansion, industrial backplane interfaces, and hot-swap I/O modules requiring stable component supply across automotive, industrial, and communications end markets.

Supply support for MC74VHC125MELG 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 specializing in energy-efficient silicon solutions for automotive, industrial, cloud, medical, and IoT applications.

The MC74VHC125MELG belongs to the VHC (Very High Speed CMOS) logic family, engineered for high-speed, low-power digital interfacing in mixed-voltage embedded systems where reliability, noise immunity, and wide supply range are essential.

FAQ

What is the maximum input voltage the MC74VHC125MELG can tolerate?

The MC74VHC125MELG inputs tolerate −0.5 V to +6.5 V DC, independent of V_CC. This allows safe connection to 5 V signals even when powered from 3.3 V, eliminating the need for external level-shifting circuitry in mixed-voltage designs. The specification is validated per Absolute Maximum Ratings in the official datasheet (Rev. 11, April 2025).

Does the MC74VHC125MELG support hot insertion?

Yes - the MC74VHC125MELG includes power-down protection: its inputs remain high-impedance and non-latching when V_CC = 0 V, and output structures prevent backfeeding. This enables safe hot-plug operation in modular systems, as confirmed in the datasheet's "MC74VHCT125A output structures provide protection when V_CC = 0 V" section.

What is the guaranteed propagation delay for the MC74VHC125MELG at 3.3 V operation?

At V_CC = 3.3 V ± 0.3 V and C_L = 15 pF, the MC74VHC125MELG guarantees t_PLH/t_PHL ≤ 8.0 ns (max) over temperature (TA ≤ 85°C), with 5.6 ns typical. This value is specified in the AC Electrical Characteristics table for MC74VHC125 and applies directly to the MC74VHC125MELG variant.

Is the MC74VHC125MELG pin-compatible with standard 74-series logic devices?

Yes - the MC74VHC125MELG is pin- and function-compatible with industry-standard 74LS125, 74ALS125, and 74F125 devices in TSSOP-14 packaging. Its pinout matches the generic quad bus buffer layout (A/OE/Y per channel), and functional behavior (non-inverting, active-high OE) aligns with JEDEC-standard 125 logic.

What package type does the MC74VHC125MELG use, and what are its key mechanical dimensions?

The MC74VHC125MELG uses the TSSOP-14 (Case 948G) package: 4.9 mm × 4.4 mm body size, 1.2 mm maximum height, and 0.65 mm lead pitch. It is Pb-free and RoHS compliant, with markings "VHC" and "125" on top. Dimensions are fully specified in the Mechanical Case Outline drawing (Document 98ASH70246A, Issue C).

MC74VHC125MELG Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: 74VHC

Package/Case:: 14-SOIC (0.209", 5.30mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Logic Type:: Buffer, Non-Inverting

Number of Elements:: 4

Number of Bits per Element:: 1

Input Type:: -

Output Type:: 3-State

Current - Output High, Low:: 8mA, 8mA

Voltage - Supply:: 2V ~ 5.5V

Operating Temperature:: -55°C ~ 125°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOEIAJ-14

MC74VHC125MELG FAQ

1.How can I place an order for MC74VHC125MELG through Aetrix?

Please submit a Request for Quotation (RFQ) for MC74VHC125MELG 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 MC74VHC125MELG reliable?

The price and inventory of MC74VHC125MELG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC74VHC125MELG is usually 5 days.

3.What payment methods are accepted for MC74VHC125MELG?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC74VHC125MELG transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MC74VHC125MELG?

MC74VHC125MELG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MC74VHC125MELG 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 MC74VHC125MELG?

For technical support, including MC74VHC125MELG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC74VHC125MELG requirements.

6.How does Aetrix verify that MC74VHC125MELG is sourced from the original manufacturer or authorized distributors?

All MC74VHC125MELG 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 MC74VHC125MELG meets industry standards.

7.What is the process for return or replacement of MC74VHC125MELG?

All MC74VHC125MELG units undergo pre-shipment inspection (PSI). If there is an issue with MC74VHC125MELG, 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 MC74VHC125MELG part is unused and in its original packaging.

Return procedure for MC74VHC125MELG:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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