My Inquiry
My Account
Texas Instruments SN74AHC125BQAR
- Part No.:
- SN74AHC125BQAR
- Manufacturer:
- Texas Instruments
- Package:
- 14-WFQFN Exposed Pad
- Datasheet:
-
SN74AHC125BQAR.pdf
- Description:
- 4-CH, 2-V TO 5.5-V BUFFERS WITH
- Quantity:
- Payment:
- Shipping:
Inventory:2,925
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SN74AHC125BQAR from Texas Instruments is a quadruple 3-state bus buffer gate IC with independent output-enable (OE) control per channel, operating from 2 V to 5.5 V supply, supporting ±8 mA output drive at 5 V, 14-pin WQFN package (3 mm × 2.5 mm), and rated for –40°C to +125°C industrial temperature range - used for signal isolation and data routing in programmable logic controllers and PoE power management.
For engineers reviewing the SN74AHC125BQAR datasheet, SN74AHC125BQAR pinout, SN74AHC125BQAR application, or SN74AHC125BQAR equivalent, key selection criteria include independent OE control per buffer, 3-state output behavior, wide VCC range compatibility, thermal performance in WQFN, and logic-level translation capability between mixed-voltage subsystems.
Technical Context
The SN74AHC125BQAR implements four identical CMOS buffer gates, each with dedicated active-low output-enable input. When OE is low, the A→Y path is enabled with propagation delay as low as 1 ns (VCC = 5 V, CL = 50 pF); when OE is high, Y enters high-impedance state. Input thresholds scale with VCC (VIH min = 3.85 V at VCC = 5.5 V; VIL max = 1.65 V).
It features rail-to-rail input tolerance (–0.5 V to 7 V), latch-up immunity >250 mA per JESD17, and ESD protection of ±1500 V HBM / ±1000 V CDM. Power dissipation capacitance is 9.5 pF at 5 V, enabling low dynamic power in high-speed digital interfaces.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 2 V to 5.5 V - supports interoperability across 2.5 V, 3.3 V, and 5 V logic domains without level shifters. |
| Output Drive | ±8 mA at VCC = 5 V - sufficient to drive standard TTL loads and moderate-capacitance PCB traces. |
| Propagation Delay | 1 ns min (A→Y, VCC = 5 V, CL = 50 pF) - enables use in sub-100 MHz data paths with timing margin. |
| 3-State Enable/Disable Time | tPZL/tPLZ ≤ 10 ns (VCC = 5 V, CL = 50 pF) - ensures clean bus arbitration and avoids output contention during state transitions. |
| Input Thresholds | VIH = 3.85 V, VIL = 1.65 V at VCC = 5.5 V - defines valid logic-high/low margins for reliable noise immunity. |
| Operating Temperature | –40°C to +125°C - qualified for under-hood automotive, industrial motor drives, and PoE-powered equipment. |
| ESD Rating | ±1500 V HBM - meets IEC 61000-4-2 Level 2 for robust handling in manufacturing and field environments. |
Pinout & Package
SN74AHC125BQAR uses a 14-pin WQFN (BQA) package measuring 3.0 mm × 2.5 mm with wettable flanks, optimized for space-constrained industrial PCBs and automated optical inspection. Thermal resistance RθJA = 88.3°C/W enables operation up to 125°C ambient with minimal heatsinking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 4, 10, 13 (OE1–OE4) | Active-low output enable | Individually disables each buffer's output to high-impedance; must be pulled high via resistor at power-up to prevent floating outputs. |
| 2, 5, 9, 12 (A1–A4) | Buffer input | Accepts CMOS-compatible inputs; tolerant to –0.5 V to 7 V, enabling safe hot-swap and mixed-voltage interfacing. |
| 3, 6, 8, 11 (Y1–Y4) | 3-state buffer output | Drives downstream logic when OE is low; presents >10⁹ Ω impedance when OE is high - isolates buses during idle or conflict conditions. |
| 7 | GND | Reference ground for all logic and power paths; requires low-inductance connection to minimize switching noise. |
| 14 | VCC | Primary power supply; bypass capacitor (0.1 µF) required adjacent to pin to suppress supply transients. |
Key Features
| Feature | Design Value |
|---|---|
| Independent OE per buffer | Enables selective routing of four data lines - e.g., microcontroller GPIO pins can dynamically select one of four sensor inputs without external mux hardware. |
| Rail-to-rail input voltage tolerance | Supports interface to legacy 5 V systems while powered from 3.3 V rails, eliminating need for discrete level translators in mixed-supply designs. |
| Low quiescent current | ICC ≤ 40 µA over full temperature range - critical for always-on monitoring circuits in flow meters and PoE-powered endpoints. |
| High noise immunity | VIH/VIL hysteresis and 1.5 V noise margin at 5 V ensure stable operation in electrically noisy motor drive and PLC environments. |
| WQFN thermal performance | RθJB = 56.8°C/W allows sustained 125°C operation with standard 2-layer PCB copper pour - reduces need for thermal vias or heatsinks. |
Applications
| Programmable Logic Controllers | Power Over Ethernet (PoE) |
|---|---|
Use Scenario: Isolating I/O expansion modules from main CPU bus during configuration or fault events. IC Role / Device Role / Timing Role: Quad buffer acts as bidirectional bus gate, enabling/disabling four parallel data lanes based on PLC scan cycle phase. Use Value: Prevents bus contention during hot-swap of I/O cards and reduces electromagnetic interference during idle cycles. | Use Scenario: Managing communication between PoE PD controller and isolated MCU in powered device. IC Role / Device Role / Timing Role: Buffers UART/SPI signals between isolated 3.3 V MCU domain and 5 V PD interface IC, with OE controlled by power-good status. Use Value: Ensures clean signal handoff during power-up sequencing and prevents backfeeding into unpowered sections. |
| Motor Drives and Controls | Electronic Point-of-Sale |
Use Scenario: Routing encoder feedback, limit switch inputs, and PWM command signals in compact servo drives. IC Role / Device Role / Timing Role: Provides galvanically isolated signal conditioning path with fast enable/disable for real-time fault response. Use Value: Enables <10 ns response to overcurrent events by disabling feedback paths before hardware shutdown triggers. | Use Scenario: Interfacing barcode scanner, receipt printer, and cash drawer drivers to a shared microcontroller bus. IC Role / Device Role / Timing Role: Acts as software-selectable signal router - only one peripheral enabled at a time to avoid address conflicts. Use Value: Reduces BOM count by replacing four discrete buffers with single quad device, saving 22 mm² PCB area in space-critical terminals. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bus buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74LVC125AQPWRQ1 | Automotive-grade AEC-Q100 qualified; same pinout but VCC = 1.65–5.5 V; lower drive (±24 mA at 3.3 V vs ±8 mA at 5 V). | Required for automotive infotainment head units; not suitable for industrial 5 V-only systems due to reduced noise margin at 5 V. | Select when automotive qualification and extended low-VCC operation are mandatory; verify VIH/VIL compatibility at target VCC. |
| 74AHC125PW,118 | NXP TSSOP-14 package (5.0 mm × 4.4 mm); identical electrical specs but higher RθJA (147.7°C/W) limits high-temp operation. | Suitable for cost-sensitive consumer electronics where board space and thermal load are less constrained. | Choose for legacy TSSOP assembly lines; expect 30% higher junction temperature rise versus SN74AHC125BQAR at same power. |
Compared with SN74LVC125AQPWRQ1 and 74AHC125PW,118, the SN74AHC125BQAR offers superior thermal efficiency in compact layouts and guaranteed 5 V operation - making it optimal for industrial edge nodes where reliability under thermal stress is critical.
Availability
SN74AHC125BQAR is available at Aetrix Electronics and suitable for programmable logic controllers, Power over Ethernet endpoints, and motor drive control systems requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for SN74AHC125BQAR 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 connectivity technologies, with over 90 years of innovation in industrial, automotive, and communications markets.
The SN74AHC125 family belongs to TI's industry-standard logic portfolio, designed specifically for robust signal routing, bus isolation, and voltage-level flexibility in harsh industrial environments.
FAQ
What is the recommended pull-up resistor value for OE pins on SN74AHC125BQAR during power-up?
The OE pins of SN74AHC125BQAR must be tied to VCC through a pull-up resistor to ensure high-impedance state at power-up. TI specifies minimum resistor value based on driver sink capability; a 10 kΩ resistor is commonly used and verified to maintain OE >2.0 V within 100 µs of VCC ramp, preventing unintended output activation during startup.
Does SN74AHC125BQAR support mixed-voltage operation between 3.3 V and 5 V domains?
Yes, SN74AHC125BQAR supports mixed-voltage operation: its inputs tolerate –0.5 V to 7 V regardless of VCC, and output VOH/VOL meet 3.3 V logic thresholds when VCC = 3.3 V. For example, with VCC = 3.3 V, VOH ≥ 2.9 V ensures reliable HIGH detection by 3.3 V receivers, while VIH = 2.1 V allows clean recognition of 5 V signals as logic HIGH.
Can SN74AHC125BQAR be used as a level shifter between 2.5 V and 5 V logic?
SN74AHC125BQAR is not a dedicated level shifter but can perform bidirectional voltage translation when VCC is set to the higher domain (e.g., 5 V). With VCC = 5 V, it accepts 2.5 V inputs (VIH min = 3.85 V at 5.5 V, but VIH = 3.15 V at 4.5 V - 2.5 V falls below threshold), so direct 2.5 V → 5 V translation requires external biasing. For true level shifting, pair SN74AHC125BQAR with resistive dividers or use TI's TXB series.
What is the maximum capacitive load SN74AHC125BQAR can drive while maintaining specified tPLH/tPHL?
SN74AHC125BQAR maintains specified propagation delay (tPLH/tPHL ≤ 6.5 ns) up to 50 pF load capacitance at VCC = 5 V. Beyond 50 pF, delay increases linearly (~0.1 ns/pF); for 100 pF loads, typical delay rises to ~11 ns. Layout best practices - short traces, ground plane, and local decoupling - are essential to stay within timing budgets.
Is SN74AHC125BQAR pin-compatible with other 14-pin AHC125 variants like SN74AHC125DR?
Yes, SN74AHC125BQAR shares identical pin function mapping with all 14-pin SN74AHC125 variants (SOIC-D, SSOP-DB, TSSOP-PW, VQFN-RGY, WQFN-BQA), including OE, A, Y, GND, and VCC positions. However, physical dimensions and thermal characteristics differ - WQFN-BQA (3 mm × 2.5 mm) requires rework of footprint and stencil design versus SOIC-D (8.65 mm × 3.91 mm).
SN74AHC125BQAR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74AHC
- Package/Case:
- 14-WFQFN Exposed Pad
- 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:
- 2V ~ 5.5V
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-WQFN (3x2.5)
SN74AHC125BQAR FAQ
1.How can I place an order for SN74AHC125BQAR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74AHC125BQAR 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 SN74AHC125BQAR reliable?
The price and inventory of SN74AHC125BQAR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74AHC125BQAR is usually 5 days.
3.What payment methods are accepted for SN74AHC125BQAR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74AHC125BQAR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74AHC125BQAR?
SN74AHC125BQAR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74AHC125BQAR 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 SN74AHC125BQAR?
For technical support, including SN74AHC125BQAR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74AHC125BQAR requirements.
6.How does Aetrix verify that SN74AHC125BQAR is sourced from the original manufacturer or authorized distributors?
All SN74AHC125BQAR 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 SN74AHC125BQAR meets industry standards.
7.What is the process for return or replacement of SN74AHC125BQAR?
All SN74AHC125BQAR units undergo pre-shipment inspection (PSI). If there is an issue with SN74AHC125BQAR, 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 SN74AHC125BQAR part is unused and in its original packaging.
Return procedure for SN74AHC125BQAR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SN74AHC125BQAR 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…
