My Inquiry
My Account
Texas Instruments SN74AHCT125DR
- Part No.:
- SN74AHCT125DR
- Manufacturer:
- Texas Instruments
- Package:
- 14-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SN74AHCT125DR.pdf
- Description:
- IC BUF NON-INVERT 5.5V 14SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:7,982
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SN74AHCT125DR from Texas Instruments is a quadruple 3-state bus buffer gate IC used for digital signal routing, isolation, and level translation in logic interface circuits. It features four independent channels, TTL-compatible inputs (VIH = 2 V, VIL = 0.8 V), 5 V supply operation (4.5–5.5 V), ±8 mA output drive, and propagation delay ≤6.5 ns at 15 pF load - deployed in microcontroller GPIO expansion, LED control, and switch debouncing.
For engineers reviewing the SN74AHCT125DR datasheet, SN74AHCT125DR pinout, SN74AHCT125DR application, or SN74AHCT125DR equivalent, this page delivers verified functional identity, SOIC-14 package mapping, real-world timing and drive specifications, and two validated alternative parts with documented technical and application differences.
Technical Context
The SN74AHCT125DR implements four independent CMOS-based buffer gates, each with dedicated active-low output-enable (OE) control. Each channel passes A→Y when OE is low and enters high-impedance state when OE is high - enabling bidirectional bus sharing and signal gating without contention.
Its TTL-voltage-compatible inputs accept 0.8 V/2.0 V thresholds across –40°C to +85°C, while output VOH ≥3.8 V and VOL ≤0.44 V at IOL/IOH = ±8 mA ensure robust noise margins and compatibility with legacy 5 V logic families including LS, ALS, and F.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5 V to 5.5 V - operates reliably within standard 5 V rail tolerances; supports stable interfacing with 5 V microcontrollers and peripherals. |
| Input Thresholds | VIH = 2.0 V, VIL = 0.8 V - directly compatible with TTL logic outputs without level-shifting circuitry. |
| Output Drive | ±8 mA - sufficient to drive LEDs, small capacitive loads (≤50 pF), and multiple 74-series inputs simultaneously. |
| Propagation Delay | tPLH/tPHL ≤ 6.5 ns @ CL = 15 pF - enables use in 20+ MHz digital control paths with predictable timing. |
| 3-State Enable Time | tPZH/tPZL ≤ 6 ns @ CL = 15 pF - ensures fast bus release for time-critical multiplexing applications. |
| Power Consumption | ICC ≤ 20 µA (static), Cpd = 14 pF - ultra-low quiescent current supports battery-sensitive designs. |
| Operating Temperature | –40°C to +85°C - qualified for commercial industrial environments including motor controls and instrumentation. |
Pinout & Package
SN74AHCT125DR is housed in a 14-pin SOIC (D) package with 1.27 mm pitch, 8.65 mm × 3.91 mm body, and gull-wing leads. Pin numbering follows JEDEC MS-012, with GND on pin 7 and VCC on pin 14.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 4, 10, 13 | OE₁, OE₂, OE₃, OE₄ | Active-low output enable for each of four independent buffers - asserted low to enable A→Y pass-through. |
| 2, 5, 9, 12 | A₁, A₂, A₃, A₄ | Buffer input terminals - accept TTL/CMOS logic signals; must be tied to VCC or GND if unused. |
| 3, 6, 8, 11 | Y₁, Y₂, Y₃, Y₄ | Buffer output terminals - deliver buffered signal or enter high-Z state when corresponding OE is high. |
| 7 | GND | Ground reference for all logic and power domains - requires low-impedance PCB connection. |
| 14 | VCC | Positive supply terminal - requires local 0.1 µF bypass capacitor placed adjacent to pin. |
Key Features
| Feature | Design Value |
|---|---|
| Independent 3-state control per channel | Enables selective bus arbitration - e.g., isolate one sensor channel while driving another without external logic. |
| TTL-compatible input thresholds | Eliminates need for external level shifters when interfacing with legacy 5 V microcontrollers or discrete logic. |
| Latch-up immunity >250 mA | Meets JESD17 - ensures robustness against transient overvoltage events in noisy industrial environments. |
| Low dynamic power dissipation | Cpd = 14 pF - reduces switching current and heat generation in high-frequency toggle applications. |
| High-impedance on power-up | OE pins default high during VCC ramp - prevents bus contention before system initialization completes. |
Applications
| Microcontroller GPIO Expansion | LED Indicator Control |
|---|---|
Use Scenario: A resource-constrained MCU uses limited GPIOs to manage multiple peripheral signals via shared data lines. IC Role / Device Role / Timing Role: SN74AHCT125DR acts as a programmable signal router - individual OE pins select which peripheral connects to the MCU data bus. Use Value: Enables 4-channel bidirectional bus isolation with <6.5 ns propagation delay, avoiding contention and reducing firmware complexity. |
Use Scenario: Driving multiple status LEDs from a single microcontroller port with current limiting and polarity flexibility. IC Role / Device Role / Timing Role: SN74AHCT125DR serves as an active-low controlled current sink/source - OE enables/disables LED current path through Y output. Use Value: Delivers ±8 mA per channel, supporting direct LED drive without external transistors while maintaining TTL-compatible control logic. |
| Switch Debounce Circuit | Noise-Immune Digital Signal Conditioning |
Use Scenario: Mechanical pushbutton inputs generate contact bounce causing false triggers in digital systems. IC Role / Device Role / Timing Role: SN74AHCT125DR buffers and gates the switch signal - OE held low, with RC filter at A input to suppress transients. Use Value: Leverages inherent hysteresis and fast edge response to eliminate slow/noisy transitions, meeting sub-10 ns timing requirements. |
Use Scenario: Long PCB traces or unshielded cables introduce noise into digital control signals entering sensitive logic sections. IC Role / Device Role / Timing Role: SN74AHCT125DR functions as a clean signal repeater - isolating noisy source from downstream logic using its 3-state capability. Use Value: Provides 20 ns/V minimum input transition rate compliance and 0.8 V/2.0 V noise margins, rejecting common-mode spikes up to ±0.8 V. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bus buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74LVC125A | Lower supply range (1.65–3.6 V), 3.3 V native logic; 24 mA drive; no TTL input compatibility. | Requires level translation for 5 V systems; suited for modern low-voltage FPGA/MCU interfaces. | Select when operating below 3.6 V or needing higher drive strength; avoid in pure 5 V TTL environments. |
| 74HC125 | CMOS-only inputs (VIH = 3.15 V min); slower tPD (~15 ns); lower ICC (≤1 µA). | Not compatible with TTL outputs; requires pull-ups for open-collector sources; less noise immune. | Choose for ultra-low static power in 5 V systems where input sources meet HC thresholds; not drop-in for TTL. |
Compared with SN74LVC125A and 74HC125, the SN74AHCT125DR uniquely bridges legacy 5 V TTL and modern CMOS systems - delivering guaranteed 2 V VIH, 5 V rail operation, and sub-7 ns timing without voltage translation overhead.
Availability
SN74AHCT125DR is available at Aetrix Electronics and suitable for microcontroller interface design, industrial LED control, and mechanical switch conditioning requiring stable component supply, long-term production continuity, and RoHS-compliant packaging.
Supply support for SN74AHCT125DR 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
Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and logic solutions with over 50 years of innovation in industrial, automotive, and communications markets.
The SN74AHCT125DR belongs to TI's AHCT logic family - engineered specifically for seamless 5 V TTL-to-CMOS interfacing, combining speed, noise immunity, and backward compatibility for industrial control and legacy system upgrades.
FAQ
What is the function of the OE pins on the SN74AHCT125DR?
Each OE pin (1OE, 2OE, 3OE, 4OE) on the SN74AHCT125DR is an active-low control that enables or disables its corresponding buffer channel. When OE is low, the A input passes to the Y output; when OE is high, the Y output enters high-impedance state. This allows independent gating of four signals - critical for bus arbitration and signal isolation in the SN74AHCT125DR.
Can the SN74AHCT125DR operate with a 3.3 V supply?
No, the SN74AHCT125DR is specified only for 4.5 V to 5.5 V operation per its Recommended Operating Conditions. Supplying 3.3 V violates the minimum VCC requirement and will result in undefined logic behavior, insufficient VOH, and potential latch-up. For 3.3 V systems, consider SN74LVC125A instead of SN74AHCT125DR.
Is the SN74AHCT125DR pin-compatible with other 74xx125 variants?
Yes - the SN74AHCT125DR shares identical SOIC-14 pinout and function mapping with SN74HC125, SN74LS125, and SN74LVC125A. However, electrical characteristics differ: SN74AHCT125DR offers TTL-compatible inputs, while others require CMOS-level inputs. Physical pin alignment is preserved, but logic-level compatibility must be verified per application.
How should unused inputs be handled on the SN74AHCT125DR?
All unused inputs on the SN74AHCT125DR - including A and OE pins - must be terminated to either VCC or GND to prevent floating states that cause excessive current draw, oscillation, or ESD susceptibility. A 10 kΩ pull-up or pull-down resistor is recommended for OE pins; direct connection is acceptable for permanently unused A inputs. This requirement applies universally across all SN74AHCT125DR channels.
What is the maximum capacitive load the SN74AHCT125DR can drive while meeting datasheet timing specs?
The SN74AHCT125DR guarantees full AC performance - including propagation delay and enable/disable timing - up to 50 pF load capacitance, as confirmed in the Switching Characteristics table. Driving >50 pF increases tPLH/tPHL and may violate setup/hold margins in high-speed systems. For heavier loads, add a series resistor or buffer stage; always verify timing margins in final layout for the SN74AHCT125DR.
SN74AHCT125DR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74AHCT
- Package/Case:
- 14-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-SOIC
SN74AHCT125DR FAQ
1.How can I place an order for SN74AHCT125DR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74AHCT125DR 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 SN74AHCT125DR reliable?
The price and inventory of SN74AHCT125DR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74AHCT125DR is usually 5 days.
3.What payment methods are accepted for SN74AHCT125DR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74AHCT125DR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74AHCT125DR?
SN74AHCT125DR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74AHCT125DR 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 SN74AHCT125DR?
For technical support, including SN74AHCT125DR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74AHCT125DR requirements.
6.How does Aetrix verify that SN74AHCT125DR is sourced from the original manufacturer or authorized distributors?
All SN74AHCT125DR 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 SN74AHCT125DR meets industry standards.
7.What is the process for return or replacement of SN74AHCT125DR?
All SN74AHCT125DR units undergo pre-shipment inspection (PSI). If there is an issue with SN74AHCT125DR, 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 SN74AHCT125DR part is unused and in its original packaging.
Return procedure for SN74AHCT125DR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SN74AHCT125DR 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
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…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
