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STMicroelectronics 74VHC126TTR
- Part No.:
- 74VHC126TTR
- Manufacturer:
- STMicroelectronics
- Package:
- 14-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
74VHC126TTR.pdf
- Description:
- IC BUF NON-INVERT 5.5V 14TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,247
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Product details
Overview
74VHC126TTR from STMicroelectronics is a quad 3-state bus buffer IC with symmetrical output drive (±8 mA), 3.8 ns typical propagation delay at 5 V, and 2 V to 5.5 V operating voltage range. It features power-down input protection (0–7 V tolerant), high noise immunity (28% VCC), and ESD robustness (2 kV). Used in voltage-level translation between 3 V and 5 V logic domains in industrial control backplanes.
For engineers reviewing the 74VHC126TTR datasheet, 74VHC126TTR pinout, 74VHC126TTR application, or 74VHC126TTR equivalent, key selection criteria include 3-state enable timing (tPZL/tPLZ ≤ 6.0 ns at 5 V), input overvoltage tolerance, rail-to-rail input compatibility, and TSSOP-14 thermal performance in dense PCB layouts.
Technical Context
The 74VHC126TTR implements four independent non-inverting buffers, each with an active-low 3-state enable (G) controlling output impedance. All inputs accept voltages up to 7 V regardless of VCC, enabling safe hot-swap and mixed-voltage interfacing.
Its C2MOS process delivers balanced tPLH ≅ tPHL propagation delays and low dynamic noise (VOLP ≤ 0.8 V), critical for clean signal integrity in synchronous bus architectures with multiple drivers sharing common data lines.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Propagation Delay (tPD) | 3.8 ns typ. at VCC = 5 V, CL = 15 pF - enables >100 MHz bus operation with margin |
| Supply Voltage Range | 2 V to 5.5 V - supports dual-rail systems (3.3 V/5 V) without level shifters |
| Output Drive Strength | ±8 mA min. - drives standard TTL loads and ≥10 CMOS inputs at full speed |
| Input Voltage Tolerance | −0.5 V to +7.0 V - allows safe interfacing with higher-voltage peripherals or floating inputs |
| Quiescent Current (ICC) | 4 µA max. at TA = 25°C - suitable for low-power standby modes in battery-backed systems |
| ESD Immunity | 2 kV HBM - meets IEC 61000-4-2 Level 2 for board-level robustness |
| Operating Temperature | −55°C to +125°C - qualified for extended industrial and automotive under-hood environments |
Pinout & Package
TSSOP-14 package: 4.4 mm × 5.0 mm body, 0.65 mm pitch, 1.05 mm max height, lead-free and RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 4, 10, 13 | G1–G4 (Active-Low Enable) | Each controls one buffer's 3-state output; low = enabled, high = high-Z |
| 2, 5, 9, 12 | A1–A4 (Data Inputs) | Accept 0–7 V regardless of VCC; internally clamped with diodes |
| 3, 6, 8, 11 | Y1–Y4 (Data Outputs) | Non-inverting buffered outputs; high-Z when corresponding G is high |
| 7 | GND | Ground reference for all I/O and internal logic; decoupling required near pin |
| 14 | VCC | Positive supply (2–5.5 V); powers internal logic and output drivers |
Key Features
| Feature | Design Value |
|---|---|
| Input Overvoltage Tolerance | Supports 0–7 V input signals independent of VCC - eliminates external clamping diodes in mixed-voltage interconnects |
| Symmetrical Output Drive | IOH = IOL = 8 mA min. - ensures matched rise/fall times and reduced bus skew |
| Low Dynamic Noise | VOLP ≤ 0.8 V at CL = 50 pF - minimizes ground bounce during simultaneous switching |
| Power-Down Input Protection | Inputs remain functional and non-damaging even with VCC = 0 V - enables hot-plug capability |
| High Noise Immunity | VNIH/VNIL = 28% VCC min. - rejects >1.4 V noise on 5 V buses and >0.84 V on 3.3 V buses |
Applications
| Industrial PLC Backplane Interface | Automotive Body Control Module (BCM) |
|---|---|
Use Scenario: Bidirectional data routing across isolated 3.3 V microcontroller and 5 V sensor interface cards in modular I/O racks. IC Role / Device Role / Timing Role: Quad buffer isolates voltage domains while maintaining timing-critical address/data bus integrity during hot-swap events. Use Value: Input overvoltage tolerance prevents latch-up during card insertion; 3.8 ns tPD ensures cycle-accurate sampling at 25 MHz bus clock. | Use Scenario: Level-shifting between 3.3 V CAN controller and 5 V analog multiplexer in centralized lighting control units. IC Role / Device Role / Timing Role: Non-inverting buffer with 3-state control enables shared analog bus arbitration without signal contention. Use Value: −55°C to +125°C rating matches under-hood thermal requirements; 2 kV ESD withstand protects against assembly handling discharge. |
| Medical Diagnostic Equipment Data Bus | Test & Measurement Instrumentation |
Use Scenario: Interfacing FPGA-based acquisition logic (3.3 V) to legacy 5 V ADC/DAC modules in portable ultrasound front-ends. IC Role / Device Role / Timing Role: Enables deterministic 3-state control of multi-drop data paths during calibration and data capture phases. Use Value: Balanced tPLH/tPHL reduces jitter-induced sampling error; low ICC supports battery-operated runtime extension. | Use Scenario: Signal conditioning path in benchtop oscilloscope trigger subsystem where multiple 3.3 V logic sources drive a common 5 V comparator input. IC Role / Device Role / Timing Role: Provides noise-immune fanout with precise enable timing to synchronize trigger event capture. Use Value: 28% VCC noise margin suppresses false triggers from switching noise; VOLP ≤ 0.8 V maintains clean threshold crossing. |
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 |
|---|---|---|---|
| SN74LVC126APW | Lower VCC range (1.65–3.6 V); no 5 V tolerance on inputs | Restricted to 3.3 V-only systems; unsuitable for 5 V interfacing | Select only if full system operates at ≤3.6 V and input overvoltage is not required |
| 74LCX126MTCX | Higher ICC (10 µA typ.); supports 3.3 V → 5 V translation via I/O-tolerant inputs but lacks 7 V absolute max rating | Marginally lower noise immunity (20% VCC); limited to commercial temperature range (0–70°C) | Choose when cost sensitivity outweighs extended temp and ESD requirements |
Compared with SN74LVC126APW and 74LCX126MTCX, the 74VHC126TTR uniquely combines 0–7 V input tolerance, −55°C to +125°C operation, and 2 kV ESD in a single TSSOP-14 package-making it the only option for ruggedized mixed-voltage industrial interfaces requiring guaranteed hot-swap resilience.
Availability
74VHC126TTR is available at Aetrix Electronics and suitable for industrial PLC backplanes, automotive body control modules, medical diagnostic data buses, and test & measurement instrumentation requiring stable component supply across extended temperature and mixed-voltage conditions.
Supply support for 74VHC126TTR 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 microcontrollers, power management ICs, sensors, and analog/mixed-signal devices for industrial, automotive, and consumer markets.
The 74VHC logic family targets high-speed, low-power, and robust interface solutions for mixed-voltage digital systems-emphasizing rail-to-rail input tolerance, ESD resilience, and extended temperature reliability.
FAQ
Can the 74VHC126TTR safely interface a 5 V microcontroller with a 3.3 V FPGA?
Yes. Its inputs tolerate 0–7 V regardless of VCC, and its outputs swing rail-to-rail within the applied VCC (2–5.5 V). With VCC = 3.3 V, it drives FPGA inputs at valid LVTTL levels; with VCC = 5 V, it accepts 5 V MCU outputs directly-no external level shifters needed.
What is the maximum capacitive load the 74VHC126TTR can drive while maintaining 3.8 ns propagation delay?
The 3.8 ns typical tPD is specified at CL = 15 pF and VCC = 5 V. At CL = 50 pF, tPD increases to 5.3 ns. For designs requiring ≤4 ns delay, total load-including PCB trace capacitance and connected inputs-must stay below ~20 pF.
Does the 74VHC126TTR support hot-swap insertion when VCC is unpowered?
Yes. Power-down protection allows all inputs to accept 0–7 V signals even when VCC = 0 V, preventing damage or back-powering. This enables safe hot-plug into live backplanes, provided current-limiting resistors are used on outputs driving powered circuits.
How does the 74VHC126TTR's noise immunity compare to standard 74HC126 devices?
It provides higher noise immunity: VNIH/VNIL = 28% VCC (min) versus 30% VCC for 74HC126. At 5 V, this equals 1.4 V noise margin-exceeding typical 74HC series (1.0–1.2 V)-due to tighter input threshold design and C2MOS process optimization.
74VHC126TTR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- 74VHC
- 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:
- 2V ~ 5.5V
- Operating Temperature:
- -55°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-TSSOP
74VHC126TTR FAQ
1.How can I place an order for 74VHC126TTR through Aetrix?
Please submit a Request for Quotation (RFQ) for 74VHC126TTR 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 74VHC126TTR reliable?
The price and inventory of 74VHC126TTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74VHC126TTR is usually 5 days.
3.What payment methods are accepted for 74VHC126TTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74VHC126TTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74VHC126TTR?
74VHC126TTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74VHC126TTR 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 74VHC126TTR?
For technical support, including 74VHC126TTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74VHC126TTR requirements.
6.How does Aetrix verify that 74VHC126TTR is sourced from the original manufacturer or authorized distributors?
All 74VHC126TTR 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 74VHC126TTR meets industry standards.
7.What is the process for return or replacement of 74VHC126TTR?
All 74VHC126TTR units undergo pre-shipment inspection (PSI). If there is an issue with 74VHC126TTR, 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 74VHC126TTR part is unused and in its original packaging.
Return procedure for 74VHC126TTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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