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Texas Instruments TL431AQDBZR
- Part No.:
- TL431AQDBZR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TL431AQDBZR.pdf
- Description:
- IC VREF SHUNT ADJ 1% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:20,076
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Product details
Overview
TL431AQDBZR from Texas Instruments is a precision programmable shunt voltage reference in SOT-23-3 package, featuring 1% initial reference voltage tolerance at 25°C, −40°C to +125°C operating temperature range, 2.47–2.52 V reference voltage (Vref), 0.2 Ω typical dynamic impedance, and 1–100 mA sink-current capability. It serves as an adjustable feedback element in isolated DC-DC converters and industrial power supplies.
For engineers reviewing the TL431AQDBZR datasheet, TL431AQDBZR pinout, TL431AQDBZR application, or TL431AQDBZR equivalent, this page delivers verified electrical specs, thermal performance data, automotive-grade temperature stability, and real-world implementation guidance for closed-loop regulation design.
Technical Context
The TL431AQDBZR implements a three-terminal adjustable shunt regulator architecture with internal error amplifier, reference, and output transistor. Its cathode-anode voltage (VKA) is programmable from Vref (~2.495 V) up to 36 V using two external resistors, enabling precise output voltage setting in flyback and forward converter feedback networks.
It operates across the full automotive temperature range (−40°C to +125°C) and exhibits 14–34 mV total reference voltage deviation over that range. The device maintains low 0.2 Ω dynamic impedance below 1 kHz and supports stable operation with load capacitance up to 10 µF depending on cathode current and VKA.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Vref tolerance @ 25°C | ±1% (A grade): ensures ±25 mV absolute accuracy at room temperature for tight feedback loop calibration |
| Operating temperature | −40°C to +125°C (Q grade): qualified for under-hood automotive and industrial motor drive applications |
| Reference voltage | 2.47–2.52 V (min–max at 25°C): enables accurate 3.3 V, 5 V, 12 V, or 24 V output regulation via resistor divider |
| Dynamic impedance | 0.2 Ω typical (≤1 kHz): provides high PSRR and low noise sensitivity in feedback path of switching regulators |
| Sink current range | 1–100 mA: supports direct optocoupler LED drive without external transistor in isolated SMPS designs |
| Reference input current | 2–4 µA typical: minimizes resistor-divider power loss and improves efficiency in high-impedance feedback networks |
| Temp drift (VI(dev)) | 14–34 mV over full range: guarantees predictable regulation shift in servo drives and AC inverters |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm body size), surface-mount, RoHS-compliant, rated for reflow soldering per JEDEC J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1: Cathode | Shunt current output node | Connects to primary-side optocoupler LED or secondary-side feedback network; sinks regulated current |
| Pin 2: Anode | Common reference return | Typically tied to system ground or negative rail; defines voltage reference point for REF pin |
| Pin 3: REF | Threshold input | Monitors divided output voltage; triggers conduction when input ≥ Vref (2.495 V) |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output voltage | Settable from 2.495 V to 36 V using two external resistors - eliminates need for multiple fixed-voltage references |
| Low output noise | Sub-20 µVRMS (0.1–10 Hz), <100 nV/√Hz (1 kHz) - preserves signal integrity in precision analog feedback loops |
| Sharp turn-on characteristic | Fast response to REF threshold crossing - enables stable regulation even with fast transient loads |
| High sink-current capability | 100 mA max continuous cathode current - directly drives optocouplers like PC817 or SFH615A without buffer transistor |
| Automotive qualification | AEC-Q100 stress-tested (Q-temp grade) - validated for use in vehicle ECUs, battery management, and ADAS power rails |
Applications
| Rack Server Power | Industrial AC/DC Converter |
|---|---|
Use Scenario: Secondary-side voltage sensing in 48 V input, 12 V/50 A isolated DC-DC module for telecom servers. IC Role / Device Role / Timing Role: Programmable shunt reference providing feedback to PWM controller via optocoupler. Use Value: Enables ±1% output regulation across line/load/temperature while reducing BOM count vs. discrete Zener+transistor solution. |
Use Scenario: Output voltage regulation in 3 kW industrial AC/DC front-end supplying PLC I/O modules. IC Role / Device Role / Timing Role: Precision reference in isolated flyback feedback path, interfacing with TLV2372 comparator and PC817 optocoupler. Use Value: Maintains 0.5% long-term stability over 10-year field life due to low temp drift and robust SOA. |
| AC Inverter Drive | Servo Drive Control Module |
Use Scenario: Auxiliary 15 V rail regulation in 3-phase VFD main control board with integrated gate driver ICs. IC Role / Device Role / Timing Role: Shunt reference stabilizing isolated auxiliary supply feeding microcontroller and current-sense amplifiers. Use Value: Survives repeated 125°C junction excursions during overload conditions without parameter shift. |
Use Scenario: Feedback reference for ±15 V dual-rail op-amp supply in servo position loop amplifier stage. IC Role / Device Role / Timing Role: High-PSRR voltage reference ensuring clean analog signal conditioning despite noisy motor current transients. Use Value: 0.2 Ω dynamic impedance suppresses ripple coupling into position error amplifiers, improving encoder resolution fidelity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACDBZR | Same SOT-23-3 package, but C-temp grade (0°C to 70°C) and tighter 0.5% Vref tolerance | Limited to commercial ambient environments; unsuitable for under-hood or factory-floor deployments | Select only if cost-sensitive consumer applications require higher initial accuracy and relaxed thermal range |
| TL431BQDBZR | Same Q-temp rating (−40°C to +125°C), but 0.5% Vref tolerance and lower VI(dev) (14–34 mV → 14–34 mV same, but tighter min/max spread) | Delivers improved regulation accuracy in high-precision servo feedback without changing layout or thermal design | Choose when ±0.5% output stability is required across full temperature range, e.g., medical power supplies or test equipment |
Compared with TL431AQDBZR, TL431ACDBZR trades automotive temperature capability for tighter initial accuracy, while TL431BQDBZR retains full Q-temp operation with enhanced reference precision-enabling upgrade paths without PCB redesign.
Availability
TL431AQDBZR is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC converters, and servo drive control modules requiring stable component supply across extended temperature ranges and multi-year production cycles.
Supply support for TL431AQDBZR 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 focused on analog and embedded processing technologies, with decades of expertise in precision analog ICs and power management solutions.
The TL431 product line was designed specifically for high-reliability voltage regulation in isolated power supplies, offering Zener-diode replacement with superior accuracy, temperature stability, and sink-current flexibility.
FAQ
What is the reference voltage accuracy of TL431AQDBZR at 25°C?
The TL431AQDBZR has a reference voltage tolerance of ±1% at 25°C, corresponding to a Vref range of 2.47 V to 2.52 V under standard test conditions (VKA = Vref, IKA = 10 mA). This A-grade specification balances cost and precision for industrial and automotive applications where tighter tolerances are not required.
Can TL431AQDBZR replace a Zener diode in feedback circuits?
Yes, TL431AQDBZR is explicitly designed as a superior Zener diode replacement. Its sharp turn-on characteristic, low 0.2 Ω dynamic impedance, and programmable 2.495–36 V output eliminate Zener limitations like poor temperature stability and high impedance. TL431AQDBZR achieves better than ±1% regulation accuracy across −40°C to +125°C.
What is the maximum cathode current supported by TL431AQDBZR?
TL431AQDBZR supports a continuous cathode current (IKA) range of 1 mA to 100 mA. At 100 mA, power dissipation must be managed within thermal limits: with RθJA = 206°C/W (SOT-23-3), maximum ambient temperature drops to ~75°C at full load. Derating is recommended above 50 mA in enclosed environments.
Does TL431AQDBZR require external compensation for stability?
TL431AQDBZR does not require external compensation in most configurations, but stability depends on load capacitance and cathode current. Per TI's Figure 6-18, oscillation risk exists above 1 µF capacitance at low IKA (<10 mA); adding a 10–100 Ω series resistor between cathode and optocoupler LED restores phase margin without affecting regulation accuracy.
How does TL431AQDBZR perform in automotive applications?
TL431AQDBZR is Q-grade qualified (−40°C to +125°C), AEC-Q100 stress-tested, and specified for 14–34 mV reference voltage deviation across that range. Its SOT-23-3 package meets automotive reflow profiles, and its 100 mA sink current directly drives common optocouplers used in ISO 26262-compliant power architectures.
TL431AQDBZR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 2.495V
- Voltage - Output (Max):
- 36 V
- Current - Output:
- 100 mA
- Tolerance:
- ±1%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 700 µA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
TL431AQDBZR FAQ
1.How can I place an order for TL431AQDBZR through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431AQDBZR 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 TL431AQDBZR reliable?
The price and inventory of TL431AQDBZR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431AQDBZR is usually 5 days.
3.What payment methods are accepted for TL431AQDBZR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431AQDBZR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431AQDBZR?
TL431AQDBZR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431AQDBZR 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 TL431AQDBZR?
For technical support, including TL431AQDBZR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431AQDBZR requirements.
6.How does Aetrix verify that TL431AQDBZR is sourced from the original manufacturer or authorized distributors?
All TL431AQDBZR 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 TL431AQDBZR meets industry standards.
7.What is the process for return or replacement of TL431AQDBZR?
All TL431AQDBZR units undergo pre-shipment inspection (PSI). If there is an issue with TL431AQDBZR, 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 TL431AQDBZR part is unused and in its original packaging.
Return procedure for TL431AQDBZR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431AQDBZR Tags
-
TL431AIDBZR
Texas Instruments
-
TL431BQDBZR
Texas Instruments
-
AN431AN-ATRG1
Diodes Incorporated
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LM4040CYM3-2.5-TR
Microchip Technology
-
LM4040CYM3-4.1-TR
Microchip Technology
-
LM4040EIM3-2.5/NOPB
Texas Instruments
-
AZ431LBNTR-G1
Diodes Incorporated
-
LM4040D20IDBZR
Texas Instruments
-
LM4041DIM3-ADJ/NOPB
Texas Instruments
-
LM4040DIM3X-2.5/NOPB
Texas Instruments
-
LM4040DIM3-2.5/NOPB
Texas Instruments
-
AZ431LANTR-G1
Diodes Incorporated
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