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

STMicroelectronics 74VHCT125ATTR

Name: 74VHCT125ATTR
Brand: STMicroelectronics
SKU: 74VHCT125ATTR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 74VHCT125ATTR

Manufacturer:: STMicroelectronics

Category:: Buffers, Drivers, Receivers, Transceivers

Package:: 14-TSSOP (0.173", 4.40mm Width)

Datasheet:: 74VHCT125ATTR.pdf

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

Quantity:: RFQ Add To RFQ list

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Inventory:1,210

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Product details

Overview

74VHCT125ATTR from STMicroelectronics is a quad 3-state bus buffer IC with TTL-compatible inputs, designed for bidirectional data bus isolation and level translation in 5V digital systems. It features 3.8 ns typical propagation delay, ±8 mA output drive, 2 µA max quiescent current at 25°C, and operates across 4.5–5.5 V supply. Used in microcontroller peripheral interfacing and memory address buffering.

For engineers reviewing the 74VHCT125ATTR datasheet, 74VHCT125ATTR pinout, 74VHCT125ATTR application, or 74VHCT125ATTR equivalent, key selection criteria include 3-state enable timing (tPLZ/tPZL ≤ 8.8 ns), input voltage tolerance up to 7 V independent of VCC, symmetrical output impedance, and ESD immunity of 2 kV per IEC 61000-4-2.

Technical Context

The device implements four independent non-inverting buffers, each with an active-low 3-state enable (G) controlling output high-impedance state. All inputs accept 0–7 V regardless of VCC, enabling safe hot-swap and mixed-voltage interface operation.

It uses sub-micron C2MOS technology with double-layer metal wiring, delivering balanced tPLH ≅ tPHL propagation delays and low dynamic noise (VOLP ≤ 0.8 V). Power-down protection ensures input/output clamping diodes remain functional during VCC = 0 V conditions.

Key Specifications

Parameter	Value and Actual Design Meaning
tPD (Typ.)	3.8 ns at VCC = 5 V - enables high-speed bus arbitration in 20+ MHz digital systems
ICC (Max)	2 µA at TA = 25°C - supports ultra-low static power in battery-backed or standby-critical designs
VIL / VIH	0.8 V / 2.0 V - guarantees reliable recognition of TTL logic levels at 5 V supply
IOL / IOH	8 mA (min) - drives standard LS-TTL loads without external pull-ups or buffers
VCC Range	4.5–5.5 V - accommodates industrial-grade 5 V rail tolerances and brown-out resilience
ESD Rating	2 kV HBM - provides robust handling integrity during PCB assembly and field service
VIN Tolerance	0–7 V independent of VCC - allows safe interfacing to 3.3 V or 5 V sources even when VCC is off

Pinout & Package

TSSOP-14 package: 4.9 × 6.4 × 1.05 mm body, 0.65 mm pitch, lead-free, RoHS-compliant surface-mount outline with exposed pad option not specified.

Pin/Terminal	Circuit Role	Design Meaning
1, 4, 10, 13	G1–G4 (OE)	Active-high 3-state enable inputs - assert high to disable output (Z-state)
2, 5, 9, 12	A1–A4	Buffer data inputs - accept TTL/CMOS logic with 0–7 V tolerance
3, 6, 8, 11	Y1–Y4	Buffered non-inverting outputs - deliver symmetrical ±8 mA drive capability
7	GND	Ground reference - common return for all internal logic and I/O structures
14	VCC	Positive supply - powers internal logic and defines output voltage swing (0–VCC)

Key Features

Feature	Design Value
Input voltage tolerance	0–7 V regardless of VCC - eliminates need for external level shifters when interfacing 3.3 V peripherals to 5 V buses
Power-down protection	Clamped I/O pins during VCC = 0 - prevents back-powering and latch-up during hot-plug or partial power-down
Dynamic noise control	VOLP ≤ 0.8 V at CL = 50 pF - reduces ground bounce and crosstalk in dense PCB layouts
Latch-up immunity	Improved vs. standard VHCT - meets JEDEC JESD78 Class II requirements for sustained immunity under stress

Applications

Microcontroller Bus Isolation

Memory Address Buffering

Use Scenario: Isolating GPIO expansion ports on an STM32F4-based industrial controller from shared data bus lines.

IC Role / Device Role / Timing Role: Quad non-inverting buffer with independent 3-state control per channel, enabling selective peripheral enable/disable without bus contention.

Use Value: Prevents signal corruption during firmware updates by disabling unused peripherals while maintaining timing integrity (tPLH/tPHL match within 0.2 ns).

Use Scenario: Driving 16-bit address lines from a Z80 CPU to multiple SRAM chips in retro-computing hardware.

IC Role / Device Role / Timing Role: Address bus driver with TTL-compatible inputs and 8 mA drive strength, ensuring setup/hold margin across 15 cm traces.

Use Value: Eliminates need for discrete transistor arrays; 3.8 ns tPD maintains 25 MHz address strobe timing budget.

Legacy System Interfacing

Hot-Swappable Module Interface

Use Scenario: Bridging 5 V ISA bus signals to modern FPGA-based coprocessor cards in test equipment.

IC Role / Device Role / Timing Role: Level-translating buffer with 0–7 V input tolerance, allowing direct connection to legacy bus lines even during power sequencing mismatches.

Use Value: Avoids external clamping diodes; 2 kV ESD rating protects FPGA I/O during card insertion/removal.

Use Scenario: Enabling/disabling sensor modules on a modular PLC backplane where VCC may be sequenced independently.

IC Role / Device Role / Timing Role: 3-state bus isolator with power-down protected I/O, permitting safe module insertion while main system remains powered.

Use Value: GND/VCC-independent input tolerance prevents backfeeding; tPZL ≤ 6.0 ns ensures clean bus release before new module asserts.

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	3.3 V only (1.65–3.6 V), lower tPD (2.5 ns typ), no 7 V input tolerance	Requires level-shifting for 5 V bus use; unsuitable for hot-swap into 5 V systems	Select only for pure 3.3 V domains needing higher speed and lower voltage operation
74HC125D,653	Wider VCC range (2–6 V), higher ICC (40 µA max), no input overvoltage tolerance beyond VCC	Lacks 0–7 V input safety margin; vulnerable to bus fault coupling during power loss	Acceptable for cost-sensitive 5 V-only designs where hot-swap and mixed-voltage operation are not required

Compared with SN74LVC125APWR and 74HC125D,653, the 74VHCT125ATTR uniquely combines 5 V TTL compatibility, 7 V input tolerance, and sub-4 ns propagation in a single TSSOP-14 package-making it the only choice for robust 5 V bus isolation with field-service safety.

Availability

74VHCT125ATTR is available at Aetrix Electronics and suitable for microcontroller bus isolation, memory address buffering, legacy system interfacing, and hot-swappable module interface applications requiring stable component supply and long-term industrial availability.

Supply support for 74VHCT125ATTR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing analog, digital, and mixed-signal ICs for automotive, industrial, and consumer markets.

The VHCT logic family targets 5 V systems requiring TTL compatibility, low power, and enhanced robustness-specifically engineered for industrial control, instrumentation, and legacy interface consolidation.

FAQ

Can 74VHCT125ATTR operate with a 3.3 V supply?

No. The 74VHCT125ATTR is specified only for 4.5–5.5 V operation. Its input thresholds (VIH = 2.0 V min, VIL = 0.8 V max) and output drive characteristics are optimized for 5 V TTL compatibility. Using 3.3 V violates recommended operating conditions and risks unreliable logic levels and reduced noise margins.

What is the maximum capacitive load this device can drive reliably?

The datasheet specifies AC performance up to 50 pF load capacitance with guaranteed tPLH/tPHL ≤ 7.5 ns at VCC = 5 V. For loads exceeding 50 pF, propagation delay increases nonlinearly; design margin requires derating or adding series termination. Output drive remains functional but timing compliance must be verified per layout and load.

Does the 74VHCT125ATTR support live insertion when VCC is unpowered?

Yes. Its inputs and outputs feature power-down protection with diode clamping, allowing 0–7 V signals to be applied safely even when VCC = 0 V. This enables hot-swap capability in backplane and modular systems, provided GND is established first and current limiting is used per IOK rating (±20 mA).

How does the 74VHCT125ATTR differ from standard 74HC125 in noise performance?

The 74VHCT125ATTR specifies VOLP ≤ 0.8 V (dynamic low-voltage quiet output) under 50 pF load, whereas standard 74HC125 lacks this parameter. This reflects optimized output stage design that suppresses ground bounce and crosstalk-critical in high-density PCBs with shared return paths and fast edge rates.

74VHCT125ATTR Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: 74VHCT

Package/Case:: 14-TSSOP (0.173", 4.40mm 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:: 4.5V ~ 5.5V

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 14-TSSOP

74VHCT125ATTR FAQ

1.How can I place an order for 74VHCT125ATTR through Aetrix?

Please submit a Request for Quotation (RFQ) for 74VHCT125ATTR 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 74VHCT125ATTR reliable?

The price and inventory of 74VHCT125ATTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74VHCT125ATTR is usually 5 days.

3.What payment methods are accepted for 74VHCT125ATTR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74VHCT125ATTR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 74VHCT125ATTR?

74VHCT125ATTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 74VHCT125ATTR 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 74VHCT125ATTR?

For technical support, including 74VHCT125ATTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74VHCT125ATTR requirements.

6.How does Aetrix verify that 74VHCT125ATTR is sourced from the original manufacturer or authorized distributors?

All 74VHCT125ATTR 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 74VHCT125ATTR meets industry standards.

7.What is the process for return or replacement of 74VHCT125ATTR?

All 74VHCT125ATTR units undergo pre-shipment inspection (PSI). If there is an issue with 74VHCT125ATTR, 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 74VHCT125ATTR part is unused and in its original packaging.

Return procedure for 74VHCT125ATTR:

1.Submit a request within 90 days.

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

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