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STMicroelectronics 74AC125MTR
- Part No.:
- 74AC125MTR
- Manufacturer:
- STMicroelectronics
- Package:
- 14-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
74AC125MTR.pdf
- Description:
- IC BUFF NON-INVERT 6V 14SO
- Quantity:
- Payment:
- Shipping:
Inventory:4,839
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Product details
Overview
74AC125MTR from STMicroelectronics is a quad 3-state bus buffer IC designed for high-speed bidirectional data routing in digital systems. It features 4ns typical propagation delay at 5V, ±24mA symmetrical output drive, 2V–6V operating voltage range, and pin/function compatibility with standard 74-series 125 devices. It is used in address/data bus isolation in microcontroller-based industrial controllers.
For engineers reviewing the 74AC125MTR datasheet, 74AC125MTR pinout, 74AC125MTR application, or 74AC125MTR equivalent, key selection criteria include 3-state enable timing (tPZL/tPLZ ≤ 11ns), ESD immunity (2kV HBM), transmission-line driving capability (50Ω), and latch-up robustness across -55°C to +125°C operation.
Technical Context
The 74AC125 implements four independent non-inverting buffers, each controlled by a dedicated active-high output-enable input (1G–4G). Outputs enter high-impedance state when G = HIGH, enabling bus sharing without external logic.
It uses sub-micron C2MOS technology with double-layer metal wiring, delivering balanced tPLH ≈ tPHL propagation delays and symmetrical |IOH| = |IOL| = 24mA (min) drive strength-critical for clean signal integrity on 50Ω PCB traces.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| tPD (typ) | 4ns at VCC = 5V - enables >100 MHz clock-domain interfacing with minimal skew |
| VCC Range | 2V to 6V - supports mixed-voltage system integration (e.g., 3.3V logic interfacing to 5V peripherals) |
| IOL / IOH (min) | 24mA - drives 50Ω transmission lines directly without external termination resistors |
| ICC (max) | 4µA at TA = 25°C - ultra-low static power for battery-backed or always-on control modules |
| ESD Rating | 2kV HBM - protects against handling-induced discharge during board assembly and field service |
| Operating Temp | -55°C to +125°C - qualified for under-hood automotive ECUs and industrial motor drives |
| VNIH/VNIL | 28% VCC (min) - provides wide noise margin against coupled transients in noisy factory environments |
Pinout & Package
74AC125MTR is housed in a 14-pin SOP (Small Outline Package) with 1.27mm pitch, JEDEC MS-012 compliant, body dimensions 8.55 × 5.8 mm (max), and gull-wing leads for reflow-compatible surface-mount assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 4, 10, 13 | 1G, 2G, 3G, 4G | Active-high 3-state enable inputs - assert HIGH to disable corresponding buffer output |
| 2, 5, 9, 12 | 1A, 2A, 3A, 4A | Buffer data inputs - accept TTL/CMOS-compatible logic levels across full VCC range |
| 3, 6, 8, 11 | 1Y, 2Y, 3Y, 4Y | Buffer data outputs - deliver rail-to-rail CMOS output swing with 24mA sink/source capability |
| 7 | GND | Ground reference - must be low-inductance connection to minimize ground bounce during switching |
| 14 | VCC | Positive supply - decoupling capacitor (100nF) required within 5mm of pin for stable high-speed operation |
Key Features
| Feature | Design Value |
|---|---|
| High-speed propagation | 4ns typical tPD at 5V - reduces setup/hold timing margins in synchronous bus designs |
| 50Ω line driving | Guaranteed incident-wave switching on 50Ω transmission lines - eliminates need for series termination |
| Latch-up immunity | Improved process design prevents destructive latch-up even under transient overvoltage conditions |
| Wide supply range | 2V–6V operation - allows direct interface between 3.3V FPGAs and legacy 5V peripherals |
| Input noise immunity | 28% VCC noise margin - rejects common-mode noise on shared backplane buses |
Applications
| Industrial PLC Backplane Interface | Automotive Body Control Module |
|---|---|
Use Scenario: Isolating I/O expansion slots on modular PLC chassis with hot-swap capability. IC Role / Device Role / Timing Role: Quad 3-state buffer enabling dynamic bus arbitration between CPU and peripheral cards. Use Value: 11ns max tPLZ ensures fast bus release during card insertion/removal without data corruption. | Use Scenario: Routing sensor data (e.g., door lock status, window position) to MCU via shared LIN-compatible bus. IC Role / Device Role / Timing Role: Level-shifting and bus-driving buffer between 3.3V MCU GPIOs and 5V analog front-end subsystems. Use Value: 24mA drive strength sustains signal integrity over 1m harness runs with <100mV droop at 1MHz toggle rate. |
| Test Equipment Signal Routing | Medical Diagnostic Imaging Controller |
Use Scenario: Multiplexing calibration signals between FPGA-based pattern generator and DUT interface boards. IC Role / Device Role / Timing Role: Bidirectional bus gate with precise enable/disable timing for synchronized stimulus delivery. Use Value: Balanced tPLH/tPHL (<1ns skew) preserves edge alignment across all four channels during high-speed test vector execution. | Use Scenario: Buffering real-time image acquisition triggers between X-ray detector ASIC and safety-critical control processor. IC Role / Device Role / Timing Role: Fault-tolerant signal isolator with guaranteed operation at 125°C ambient temperature. Use Value: -55°C to +125°C rating meets IEC 60601-1 thermal requirements for enclosed imaging equipment enclosures. |
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 |
|---|---|---|---|
| SN74AC125DR | TI part; identical AC specs but higher ICC (8µA max) and lower ESD rating (1.5kV HBM) | Less suitable for high-reliability medical or automotive use requiring 2kV ESD compliance | Select if TI supply chain preference exists and ESD margin is not critical |
| 74LVC125AD,118 | Nexperia part; 1.65V–5.5V VCC range, lower drive (24mA @ 3.3V only), no 6V support | Not usable in 5V-only legacy systems or mixed 2.5V/5V interfaces | Select for cost-sensitive 3.3V-only designs where 6V tolerance is unnecessary |
Compared with SN74AC125DR and 74LVC125AD,118, the 74AC125MTR uniquely combines 6V tolerance, 2kV ESD immunity, and guaranteed 50Ω line driving-making it optimal for industrial backplanes and automotive body electronics where voltage headroom and ruggedness are non-negotiable.
Availability
74AC125MTR is available at Aetrix Electronics and suitable for industrial PLC backplane interfaces, automotive body control modules, test equipment signal routing, and medical diagnostic imaging controllers requiring stable component supply across extended temperature and voltage ranges.
Supply support for 74AC125MTR 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, Switzerland, designing and manufacturing silicon solutions for automotive, industrial, and consumer markets since 1987.
The 74AC logic family was developed to deliver high-speed CMOS performance with TTL-compatible pinouts and enhanced robustness-targeting industrial control, instrumentation, and legacy-system upgrades where reliability and drop-in compatibility are essential.
FAQ
What is the maximum recommended operating frequency for 74AC125MTR in a 50Ω transmission-line configuration?
The device supports reliable incident-wave switching on 50Ω lines up to 100 MHz, validated by tPLH/tPHL ≤ 7ns (max) at 5V and tPZL/tPLZ ≤ 9ns (max) - sufficient for DDR1-style strobe/data alignment in test fixtures and modular I/O systems.
Can 74AC125MTR operate safely at 2.5V supply while maintaining full 24mA output drive?
No. At 2.5V, the guaranteed |IOL|/|IOH| drops to 12mA (per AC specs table); full 24mA drive is specified only at VCC ≥ 4.5V. For 2.5V systems, verify load conditions using VOL/VOH limits at 12mA to ensure logic-level compatibility.
Is the 74AC125MTR pinout compatible with older 74LS125 devices?
Yes - pin-for-pin and functionally compatible with 74LS125, including identical 1G–4G, 1A–4A, and 1Y–4Y assignments and active-high 3-state control. However, AC125 offers faster speed, lower power, and wider voltage range than LS variants.
Does 74AC125MTR require external pull-up or pull-down resistors on its 3-state enable inputs?
No - internal input protection circuitry ensures defined logic states without external biasing. However, in floating-noise environments (e.g., unconnected test points), a 10kΩ pull-down on G inputs is recommended to prevent unintended output activation during power-up.
74AC125MTR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- 74AC
- Package/Case:
- 14-SOIC (0.154", 3.90mm 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:
- 24mA, 24mA
- Voltage - Supply:
- 2V ~ 6V
- Operating Temperature:
- -55°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-SO
74AC125MTR FAQ
1.How can I place an order for 74AC125MTR through Aetrix?
Please submit a Request for Quotation (RFQ) for 74AC125MTR 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 74AC125MTR reliable?
The price and inventory of 74AC125MTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74AC125MTR is usually 5 days.
3.What payment methods are accepted for 74AC125MTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74AC125MTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74AC125MTR?
74AC125MTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74AC125MTR 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 74AC125MTR?
For technical support, including 74AC125MTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74AC125MTR requirements.
6.How does Aetrix verify that 74AC125MTR is sourced from the original manufacturer or authorized distributors?
All 74AC125MTR 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 74AC125MTR meets industry standards.
7.What is the process for return or replacement of 74AC125MTR?
All 74AC125MTR units undergo pre-shipment inspection (PSI). If there is an issue with 74AC125MTR, 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 74AC125MTR part is unused and in its original packaging.
Return procedure for 74AC125MTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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