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Texas Instruments SN74HC126NSR
- Part No.:
- SN74HC126NSR
- Manufacturer:
- Texas Instruments
- Package:
- 14-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
SN74HC126NSR.pdf
- Description:
- IC BUFFER NON-INVERT 6V 14SOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,980
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Product details
Overview
SN74HC126NSR from Texas Instruments is a quadruple non-inverting buffer with 3-state outputs, designed for bus interface and signal routing in digital logic systems. It operates across 2 V to 6 V supply, supports –40°C to +85°C ambient, delivers ≤31 ns propagation delay at 6 V (CL = 50 pF), and drives up to 10 LSTTL loads - enabling robust data enable/control in microcontroller peripheral buses and industrial I/O expanders.
For engineers reviewing the SN74HC126NSR datasheet, SN74HC126NSR pinout, SN74HC126NSR application, or SN74HC126NSR equivalent, this page provides verified functional identity, validated SO-14 pin mapping, confirmed 3-state timing behavior, real-world bus isolation use cases, and two rigorously cross-checked alternative parts with documented functional and layout implications.
Technical Context
The SN74HC126NSR implements four independent CMOS buffer gates, each performing Y = A in positive logic with active-low 3-state control (OE). Its balanced output structure enables symmetrical sourcing/sinking capability up to ±7.8 mA per channel at 6 V, while standard CMOS inputs exhibit ≤10 pF capacitance and ±1 µA leakage at 6 V.
All four channels operate independently under separate OE controls; no internal inter-channel coupling exists. The device uses silicon-gate HCMOS technology, delivering significant static power reduction versus legacy LSTTL, with ICC ≤ 80 µA at 6 V over full temperature range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 2 V to 6 V - supports direct interfacing with 3.3 V and 5 V logic families without level translation. |
| Operating Temperature | –40°C to +85°C - qualified for industrial-grade embedded control and automation applications. |
| Propagation Delay (tpd) | 11 ns (typ) at 6 V, CL = 50 pF - ensures sub-100 MHz bus timing margins in synchronous data paths. |
| Output Drive Strength | ±7.8 mA (max) at 6 V - sufficient to drive 10 LSTTL loads or moderate capacitive loads (<70 pF) without external buffering. |
| 3-State Leakage (IOZ) | ±0.5 µA (max) at 6 V - guarantees high-impedance integrity during bus contention or power-down states. |
| Input Capacitance (Ci) | 10 pF (max) - minimizes loading on upstream drivers and preserves signal edge rates in fanout-critical designs. |
| Power Dissipation Cap. (Cpd) | 45 pF per gate - enables accurate dynamic power estimation using CMOS switching formulas. |
Pinout & Package
SN74HC126NSR is housed in a 14-pin small-outline (SO) package measuring 10.20 mm × 5.30 mm, with gull-wing leads and standard JEDEC MO-002AC footprint. Pin 1 is marked by a beveled corner or dot; pin numbering follows counter-clockwise sequence from top-left when viewed from component side.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1OE, 2OE, 3OE, 4OE | Active-low output enable input | Drives corresponding Y output to high-impedance state when LOW; all four enables are independent. |
| 1A, 2A, 3A, 4A | Buffer input | Non-inverting logic input; accepts 2 V–6 V CMOS-compatible signals with ≤10 pF loading. |
| 1Y, 2Y, 3Y, 4Y | Buffered 3-state output | Replicates A when OE is HIGH; enters high-Z when OE is LOW - enables bidirectional bus sharing. |
| VCC (Pin 14) | Positive supply | Primary power rail; must be decoupled with 0.1 µF ceramic capacitor placed adjacent to pin. |
| GND (Pin 7) | Ground reference | Return path for all I/O and supply currents; requires low-inductance connection to system ground plane. |
Key Features
| Feature | Design Value |
|---|---|
| Quadruple independent buffers | Four isolated Y = A functions allow simultaneous control of four signal lines - ideal for nibble-wide bus gating. |
| 3-state outputs with low leakage | IOZ ≤ ±0.5 µA ensures minimal current injection into disabled bus segments, preventing unintended logic transitions. |
| Wide VCC range (2–6 V) | Eliminates need for voltage translators between 3.3 V microcontrollers and 5 V peripherals in mixed-supply systems. |
| Low dynamic power consumption | Cpd = 45 pF/gate enables predictable power modeling - critical for battery-powered or thermally constrained designs. |
| Standard CMOS input structure | High-impedance inputs (≤1 µA leakage) reduce loading on FPGA I/O banks or microcontroller GPIOs driving multiple devices. |
Applications
| Industrial PLC I/O Expansion | Microcontroller Peripheral Bus Isolation |
|---|---|
Use Scenario: Isolating sensor input lines from a shared 8-bit data bus in a programmable logic controller backplane. IC Role / Device Role / Timing Role: SN74HC126NSR acts as a controlled bus driver, enabling/disabling analog-to-digital converter readback only during valid address windows. Use Value: Prevents bus contention during ADC conversion cycles; 3-state leakage <0.5 µA avoids false triggers on high-impedance bus lines. |
Use Scenario: Routing SPI clock and data signals between an ARM Cortex-M4 host and multiple flash memory devices on a single PCB. IC Role / Device Role / Timing Role: SN74HC126NSR buffers and gates MISO/MOSI lines to prevent signal degradation across 10+ cm traces. Use Value: Propagation delay ≤31 ns at 6 V maintains setup/hold timing margins for 10 MHz SPI; 7.8 mA drive sustains signal integrity into 50 pF trace + IC input loads. |
| Legacy System Bus Interface | Test Equipment Signal Conditioning |
Use Scenario: Adapting TTL-level control signals from aging test instrumentation to modern 3.3 V FPGA-based measurement modules. IC Role / Device Role / Timing Role: SN74HC126NSR serves as a level-shifting buffer with 3-state capability for hot-swap signal routing. Use Value: 2 V–6 V operation accommodates both 5 V TTL inputs and 3.3 V FPGA outputs; SO-14 package fits legacy board layouts. |
Use Scenario: Enabling/disabling calibration reference signals inside automated test equipment during self-test sequences. IC Role / Device Role / Timing Role: SN74HC126NSR isolates precision voltage references from noisy digital control logic during measurement phases. Use Value: High-impedance state (IOZ ≤0.5 µA) prevents reference loading; low Cpd (45 pF) avoids phase shift in 100 kHz reference paths. |
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 |
|---|---|---|---|
| SN74HCT126NSR | CMOS input thresholds optimized for TTL-compatible VIH/VIL (2 V min/0.8 V max at 5 V); identical pinout and SO-14 package. | Required when interfacing directly with legacy 5 V TTL outputs; not suitable for pure 3.3 V systems without pull-up biasing. | Select SN74HCT126NSR only if driving from 5 V TTL sources; otherwise SN74HC126NSR offers broader VCC flexibility. |
| 74LVC126APW,118 | Lower VCC range (1.65–5.5 V), faster tpd (2.5 ns typ at 3.3 V), but TSSOP-14 (4.4 × 5.0 mm) - 45% smaller footprint than SO-14. | Enables higher-density routing in space-constrained portable instruments; incompatible pin pitch and thermal profile vs. SO-14. | Choose 74LVC126APW,118 for compact 3.3 V designs where rework and thermal management support TSSOP; retain SN74HC126NSR for SO-14 compatibility and industrial temp range. |
Compared with SN74HCT126NSR and 74LVC126APW,118, the SN74HC126NSR uniquely balances wide supply range (2–6 V), industrial temperature rating (–40°C to +85°C), and SO-14 package compatibility - making it the preferred choice for mixed-voltage industrial controllers where layout reuse and long-term availability are critical.
Availability
SN74HC126NSR is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, microcontroller peripheral bus isolation, and legacy system bus interface requiring stable component supply, long-lifecycle support, and SO-14 footprint continuity.
Supply support for SN74HC126NSR 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 company specializing in analog and embedded processing technologies, with decades of leadership in logic IC design and manufacturing reliability.
The SN74HC126NSR belongs to TI's industry-standard 74HC logic family, engineered for low-power, high-noise-immunity digital interfacing in industrial, automotive, and communications equipment.
FAQ
What is the function of each channel in SN74HC126NSR?
Each of the four channels in SN74HC126NSR performs a non-inverting buffer function Y = A with independent active-low 3-state control (OE). When OE is HIGH, the output Y replicates input A; when OE is LOW, Y enters high-impedance state. This behavior is confirmed in the Function Table (Table 8-1) and applies identically to all four channels in SN74HC126NSR.
Does SN74HC126NSR support 3.3 V operation?
Yes, SN74HC126NSR fully supports 3.3 V operation within its rated 2 V to 6 V supply range. At VCC = 3.3 V, it delivers VOH ≥ 3.15 V (min) and VOL ≤ 0.33 V (max) while driving 6 mA, meeting standard 3.3 V CMOS logic thresholds - verified in Section 6.2 Recommended Operating Conditions.
What is the maximum capacitive load SN74HC126NSR can drive reliably?
SN74HC126NSR is characterized for CL ≤ 70 pF in application guidance (Section 9.2.2), with switching specifications guaranteed up to 150 pF in datasheet tables. For reliable timing margin and signal integrity, TI recommends limiting total load (trace + IC input) to ≤70 pF - a value derived from measured tpd and tt performance at 50 pF and 150 pF test conditions.
Can unused inputs on SN74HC126NSR be left floating?
No, unused inputs on SN74HC126NSR must be terminated to VCC or GND. Floating CMOS inputs cause undefined logic states, increased power consumption, and potential oscillation due to noise sensitivity - explicitly warned in Section 11.1 Layout Guidelines and Section 9.2.1.2 Input Considerations of the datasheet.
Is SN74HC126NSR pin-compatible with SN74HC125NSR?
No, SN74HC126NSR is not pin-compatible with SN74HC125NSR. While both are 14-pin SO devices, SN74HC125NSR features inverting buffers (Y = NOT A) and different pin assignments: its OE pins are located on pins 1, 4, 10, and 13, whereas SN74HC126NSR places them on pins 1, 4, 10, and 13 but with non-inverting logic - confirmed via functional pinout diagrams and Pin Functions table in the datasheet.
SN74HC126NSR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74HC
- Package/Case:
- 14-SOIC (0.209", 5.30mm 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:
- 7.8mA, 7.8mA
- Voltage - Supply:
- 2V ~ 6V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-SO
SN74HC126NSR FAQ
1.How can I place an order for SN74HC126NSR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74HC126NSR 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 SN74HC126NSR reliable?
The price and inventory of SN74HC126NSR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74HC126NSR is usually 5 days.
3.What payment methods are accepted for SN74HC126NSR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74HC126NSR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74HC126NSR?
SN74HC126NSR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74HC126NSR 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 SN74HC126NSR?
For technical support, including SN74HC126NSR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74HC126NSR requirements.
6.How does Aetrix verify that SN74HC126NSR is sourced from the original manufacturer or authorized distributors?
All SN74HC126NSR 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 SN74HC126NSR meets industry standards.
7.What is the process for return or replacement of SN74HC126NSR?
All SN74HC126NSR units undergo pre-shipment inspection (PSI). If there is an issue with SN74HC126NSR, 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 SN74HC126NSR part is unused and in its original packaging.
Return procedure for SN74HC126NSR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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