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Texas Instruments SN74AHC126N
- Part No.:
- SN74AHC126N
- Manufacturer:
- Texas Instruments
- Package:
- 14-DIP (0.300", 7.62mm)
- Datasheet:
-
SN74AHC126N.pdf
- Description:
- IC BUF NON-INVERT 5.5V 14DIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,307
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Product details
Overview
SN74AHC126N from Texas Instruments is a quadruple bus buffer gate with independent 3-state outputs, designed for digital signal routing and bus isolation in 2V–5.5V systems. It delivers 3.8 ns typical propagation delay at 5 V, supports ±25 mA output drive, and features latch-up immunity exceeding 250 mA per JESD 17 - used in logic-level translation, LED driving, and transmission line interfacing.
For engineers reviewing the SN74AHC126N datasheet, SN74AHC126N pinout, SN74AHC126N application, or SN74AHC126N equivalent, key selection criteria include its 14-pin PDIP package, quad-channel 3-state architecture, rail-to-rail input compatibility, low-power AHC logic family performance, and industrial temperature range (–40°C to +85°C).
Technical Context
This device implements four identical non-inverting buffer channels (Y = A), each with dedicated active-low output enable (OE) control. Each channel operates independently, enabling selective bus gating without crosstalk or shared control constraints.
All inputs are standard CMOS with ≤10 pF input capacitance and ±1 μA leakage; outputs feature balanced sourcing/sinking capability (±8 mA at 5 V), clamped I/O structures for ESD robustness (±2000 V HBM), and guaranteed high-impedance state during power sequencing when OE is pulled low.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 2 V to 5.5 V - supports mixed-voltage system interfacing and battery-backed operation down to 2 V. |
| tPD (typ) | 3.8 ns at 5 V - enables high-speed data path control in sub-10 ns timing-critical applications. |
| IOL / IOH | ±8 mA at 5 V - drives standard TTL loads and short PCB traces without external buffering. |
| IOZ (Off-State Leakage) | ±2.5 μA max - ensures minimal bus contention during 3-state hold in multi-driver systems. |
| Operating Temp | –40°C to +85°C - qualified for industrial-grade embedded control and instrumentation environments. |
| ESD Rating | ±2000 V HBM - meets standard handling requirements without additional protection circuitry. |
| Input Capacitance | 10 pF max - minimizes loading on upstream drivers and preserves signal integrity in fan-out scenarios. |
Pinout & Package
The SN74AHC126N uses a 14-pin plastic dual in-line package (PDIP) with 0.3-inch body width and through-hole mounting. Pin 1 is marked by a notch or dot; thermal pad is not present in this variant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1OE, 2OE, 3OE, 4OE | Active-low output enable inputs | Individually disable each buffer's output to high-impedance state; tied to GND via pull-down for power-up safety. |
| 1A–4A | Buffer input terminals | Accept CMOS-compatible logic signals; must be terminated to VCC or GND if unused to prevent floating inputs. |
| 1Y–4Y | Buffer output terminals | Deliver inverted-pass-through logic (Y = A); drive bus lines or LEDs directly with ±8 mA capability at 5 V. |
| VCC (Pin 14) | Positive supply | Supplies core logic and output drivers; requires local 0.1 μF bypass capacitor near pin. |
| GND (Pin 7) | Ground reference | Common return for all channels; connects to system ground plane to minimize noise coupling. |
Key Features
| Feature | Design Value |
|---|---|
| Quad independent 3-state buffers | Enables selective isolation of four separate data paths without shared enable logic or timing skew. |
| Balanced CMOS output drive | Sources and sinks equal current (±8 mA @ 5 V), ensuring consistent rise/fall times and reduced signal distortion. |
| Rail-to-rail input voltage range | Accepts VI from 0 V to VCC (up to 5.5 V), allowing direct interface with diverse logic families including 3.3 V and 5 V systems. |
| Power-up 3-state default | Outputs remain high-impedance until OE is actively asserted, preventing bus conflicts during system reset or boot. |
| Latch-up immunity | Exceeds 250 mA per JESD 17 - eliminates risk of destructive latch-up under transient overvoltage or ESD events. |
Applications
| LED Driver Interface | Bus Isolation in Microcontroller Systems |
|---|---|
Use Scenario: Driving multiple indicator LEDs from a microcontroller GPIO bank with limited current drive. IC Role / Device Role / Timing Role: Level-shifting and current-boosting buffer between MCU outputs and LED anodes/cathodes. Use Value: Eliminates need for discrete transistors; leverages ±8 mA per channel to drive common-anode or common-cathode LED arrays directly. | Use Scenario: Isolating shared address/data buses between two microcontrollers or peripherals operating at different voltage levels. IC Role / Device Role / Timing Role: Directionless bus buffer with per-channel 3-state control to prevent contention during arbitration. Use Value: Enables safe bidirectional communication using only four independent gates - no direction pin or external logic required. |
| Transmission Line Termination | Digital Signal Enable/Disable |
Use Scenario: Driving unterminated PCB traces longer than 10 cm carrying 10+ MHz digital clocks or data signals. IC Role / Device Role / Timing Role: Low-capacitance (10 pF), fast-edge driver that matches trace impedance and reduces reflections. Use Value: Delivers clean edges with <3.8 ns delay and controlled slew rate - avoids overshoot/ringing seen with unbuffered CMOS drivers. | Use Scenario: Enabling/disabling a clock or reset signal path based on system mode (e.g., sleep/wake transitions). IC Role / Device Role / Timing Role: Single-channel gate with OE-controlled 3-state output acting as a programmable signal switch. Use Value: Provides glitch-free signal gating: output goes high-Z before new state asserts, eliminating runt pulses during switching. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bus buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74AHCT126N | TTL-compatible inputs (VIH = 2 V min at 4.5 V), slightly higher ICC (40 μA vs. 4 μA typ), same pinout and 3-state behavior. | Better suited for interfacing with legacy 5 V TTL outputs; less ideal for low-noise 3.3 V CMOS systems due to input threshold mismatch. | Select SN74AHCT126N only when driving from older TTL sources; otherwise prefer SN74AHC126N for pure CMOS compatibility and lower static power. |
| 74LVC126N | Lower VCC range (1.65–5.5 V), higher speed (2.5 ns tPD at 3.3 V), but reduced output drive (±24 mA vs. ±25 mA) and no MIL-spec latch-up rating. | Optimized for ultra-low-voltage portable designs; lacks JESD 17 latch-up certification required in industrial/motor-control environments. | Choose 74LVC126N for battery-powered or space-constrained designs needing sub-3 ns delay; retain SN74AHC126N where latch-up immunity and industrial temp stability are mandatory. |
Compared with SN74AHCT126N and 74LVC126N, the SN74AHC126N offers the best balance of wide supply range, certified latch-up immunity, and predictable 3-state behavior across –40°C to +85°C - making it the preferred choice for robust industrial bus management where reliability outweighs marginal speed gains.
Availability
SN74AHC126N is available at Aetrix Electronics and suitable for industrial control panels, test equipment interfaces, and legacy system upgrades requiring stable component supply and long-term obsolescence support.
Supply support for SN74AHC126N 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 90 years of innovation in industrial, automotive, and communications markets.
The SN74AHC126N belongs to TI's advanced high-speed CMOS (AHC) logic family, engineered for low-power, high-noise-immunity digital interfacing in industrial automation and instrumentation systems.
FAQ
What is the maximum output current rating for SN74AHC126N?
The SN74AHC126N supports ±25 mA continuous output current per channel, verified across the full operating temperature range (–40°C to +85°C). This rating applies to both sourcing (IOH) and sinking (IOL) modes at VCC = 5 V, and is defined in the Absolute Maximum Ratings table. Exceeding this limit risks permanent damage or degraded latch-up immunity.
Does SN74AHC126N support mixed-voltage operation between 3.3 V and 5 V domains?
Yes, SN74AHC126N supports true mixed-voltage operation: its inputs accept logic-high signals up to VCC (max 5.5 V), and its outputs swing rail-to-rail. When powered at 3.3 V, it correctly interprets 5 V inputs (within absolute max VI = 7 V), and when powered at 5 V, it drives 3.3 V-tolerant loads safely - enabling seamless level translation without external resistors or translators.
How should unused inputs be handled on SN74AHC126N?
All unused inputs on SN74AHC126N must be terminated to either VCC or GND - never left floating. TI's application report SCBA004 confirms that floating CMOS inputs cause excessive current draw and potential oscillation. A 10-kΩ pull-up or pull-down resistor is recommended for unused OE or A pins to ensure deterministic logic states and stable power consumption.
What is the thermal resistance (RθJA) of the SN74AHC126N PDIP package?
The SN74AHC126N in its 14-pin PDIP (N) package has a junction-to-ambient thermal resistance (RθJA) of 124.6°C/W, measured under standard JEDEC test conditions (single-layer board, no airflow). This value assumes proper PCB layout with adequate copper pour; actual thermal performance improves with added ground plane area and thermal vias beneath the package footprint.
Is SN74AHC126N pin-compatible with older 74LS126 or 74HC126 devices?
No, SN74AHC126N is not pin-compatible with 74LS126 (which uses different pin assignments for OE and outputs) nor with 74HC126 (same pinout but incompatible electrical characteristics). While SN74AHC126N shares the same 14-pin PDIP footprint as SN74HC126, its AHC family's lower input thresholds and higher speed require careful validation of timing margins and bus loading in drop-in replacements.
SN74AHC126N Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74AHC
- Package/Case:
- 14-DIP (0.300", 7.62mm)
- Packaging:
- Bulk
- 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:
- 2V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 14-PDIP
SN74AHC126N FAQ
1.How can I place an order for SN74AHC126N through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74AHC126N 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 SN74AHC126N reliable?
The price and inventory of SN74AHC126N are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74AHC126N is usually 5 days.
3.What payment methods are accepted for SN74AHC126N?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74AHC126N transactions.
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4.How is shipping managed for SN74AHC126N?
SN74AHC126N orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74AHC126N 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 SN74AHC126N?
For technical support, including SN74AHC126N datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74AHC126N requirements.
6.How does Aetrix verify that SN74AHC126N is sourced from the original manufacturer or authorized distributors?
All SN74AHC126N 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 SN74AHC126N meets industry standards.
7.What is the process for return or replacement of SN74AHC126N?
All SN74AHC126N units undergo pre-shipment inspection (PSI). If there is an issue with SN74AHC126N, 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 SN74AHC126N part is unused and in its original packaging.
Return procedure for SN74AHC126N:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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