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Texas Instruments TL431QDBVT
- Part No.:
- TL431QDBVT
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
TL431QDBVT.pdf
- Description:
- IC VREF SHUNT ADJ 2.2% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:799
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Product details
Overview
TL431QDBVT from Texas Instruments is a precision programmable shunt voltage reference in SOT-23-3 package, delivering 2.495 V nominal reference voltage with ±0.5% initial tolerance (B-grade), −40°C to +125°C operating range, and 0.2 Ω typical dynamic impedance. It serves as a stable feedback element in isolated DC-DC converters, AC/DC power supplies, and servo drive voltage regulation circuits.
For engineers reviewing the TL431QDBVT datasheet, TL431QDBVT pinout, TL431QDBVT application, or TL431QDBVT equivalent, this page provides verified electrical specs, automotive-grade thermal performance, pin-level functional roles, real-world use cases in industrial power systems, and validated alternative options for design continuity.
Technical Context
The TL431QDBVT implements an adjustable shunt regulator architecture with internal error amplifier, reference, and output transistor - enabling precise voltage regulation via external resistor divider between cathode and reference pins. Its Q-temp grade guarantees operation across −40°C to +125°C, making it suitable for under-hood automotive and industrial motor control environments.
It features low 14 mV max reference voltage drift over full temperature range, 2–4 µA reference input current, and sink-current capability from 1 mA to 100 mA. The device replaces discrete Zener diodes with superior thermal stability, sharp turn-on, and predictable dynamic impedance below 0.5 Ω up to 1 kHz.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V nominal (2.483–2.507 V for B-grade at 25°C); sets feedback threshold in closed-loop power supply designs. |
| Initial Tolerance | ±0.5% at 25°C (B-grade); enables high-accuracy output regulation without trimming in production. |
| Operating Temperature | −40°C to +125°C (Q-grade); qualified for automotive engine bay and industrial servo drive applications. |
| Dynamic Impedance | 0.2 Ω typical (≤0.5 Ω up to 1 kHz); ensures minimal output voltage perturbation under load transients. |
| Sink Current Range | 1 mA to 100 mA; supports direct interface with optocoupler LEDs in isolated flyback feedback loops. |
| Reference Input Current | 2–4 µA at 25°C; allows high-value feedback resistors (>1 MΩ) to minimize power loss in battery-powered systems. |
| Temp Drift (VI(dev)) | 14–34 mV over −40°C to +125°C; quantifies total reference voltage variation across full automotive temperature range. |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm body size), surface-mount, lead-free, RoHS-compliant. Pin 1 = Cathode, Pin 2 = Reference, Pin 3 = Anode.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Pin 1) | Shunt current output node | Connects to primary-side optocoupler LED or regulation point; sinks current to maintain Vref at divider junction. |
| Reference (Pin 2) | High-impedance sensing input | Monitors voltage across external R1/R2 divider; triggers regulation when voltage exceeds 2.495 V. |
| Anode (Pin 3) | Common return path | Typically tied to system ground or negative rail; defines reference potential for internal error amplifier. |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output voltage | 2.5 V to 36 V via two external resistors - enables flexible feedback design across wide output ranges. |
| Low output noise | Sub-20 µVPP (0.1–10 Hz); critical for low-noise analog references and precision ADC biasing. |
| Sharp turn-on characteristic | Fast response to reference threshold crossing - improves transient regulation in switching supplies. |
| Automotive temperature grade | Q-grade qualification (−40°C to +125°C) - meets AEC-Q100 stress test requirements for reliability. |
| Low dynamic impedance | 0.2 Ω typical - maintains stable reference voltage despite cathode current variations up to 100 mA. |
Applications
| AC Inverter Control | Rack Server PSU |
|---|---|
Use Scenario: Voltage feedback loop in 3-phase IGBT gate driver power stage for variable-frequency drives. IC Role / Device Role / Timing Role: Shunt reference providing stable 2.5 V threshold to error amplifier controlling isolated DC bus voltage. Use Value: Enables ±1% output voltage accuracy over motor startup surge and ambient temperature swings up to 125°C. |
Use Scenario: Secondary-side feedback in 12 V/54 A isolated LLC resonant converter for data center servers. IC Role / Device Role / Timing Role: Precision reference for optocoupler-coupled feedback path ensuring tight cross-regulation across multiple outputs. Use Value: Maintains <±0.5% output tolerance across 10–100% load and −40°C to +85°C ambient, meeting Intel VR13 spec. |
| Servo Drive Power Module | Notebook Adapter Regulation |
Use Scenario: Overvoltage protection and voltage setpoint in 48 V input servo amplifier with regenerative braking. IC Role / Device Role / Timing Role: Programmable shunt reference triggering crowbar circuit when bus voltage exceeds 55 V. Use Value: Delivers 14 mV max temp drift over −40°C to +125°C, ensuring consistent trip point across thermal cycling. |
Use Scenario: Feedback reference in 19.5 V/3.33 A flyback adapter for ultrabook platforms. IC Role / Device Role / Timing Role: Regulates output by adjusting optocoupler LED current based on sampled output voltage. Use Value: Achieves <±1% line/load regulation with 2–4 µA reference current, minimizing standby power consumption. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431CDBVR | C-grade (0°C to 70°C), same SOT-23-3 package and B-grade electrical specs but narrower temp range. | Not qualified for automotive or extended industrial environments requiring >85°C operation. | Select only for commercial-grade applications where cost optimization outweighs thermal robustness. |
| TLVH431QDBVR | Lower 1.24 V reference voltage, 1.5% initial tolerance, Q-grade temp range, same SOT-23-3 footprint. | Used where lower reference voltage enables higher resistor values or reduced quiescent current in ultra-low-power systems. | Choose when 1.24 V reference suffices and tighter 0.5% tolerance is not required. |
Compared with TL431CDBVR and TLVH431QDBVR, TL431QDBVT uniquely combines automotive-grade temperature range, ±0.5% initial accuracy, and 2.495 V reference - making it optimal for high-reliability power feedback where both precision and thermal resilience are mandatory.
Availability
TL431QDBVT is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC conversion, and servo drive control modules requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TL431QDBVT 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 power management ICs, with decades of expertise in precision reference and power control technologies.
The TL431 product line was designed specifically for high-stability shunt regulation in isolated power supplies, industrial motor drives, and automotive subsystems - emphasizing thermal robustness, low drift, and seamless Zener diode replacement.
FAQ
What is the reference voltage tolerance of TL431QDBVT at 25°C?
The TL431QDBVT has a ±0.5% initial reference voltage tolerance at 25°C (B-grade specification), corresponding to a 2.483 V to 2.507 V range. This tight tolerance is confirmed in Section 6.13 of the TI SLVS543S datasheet and enables high-accuracy feedback without calibration. TL431QDBVT maintains this specification across its full −40°C to +125°C operating range with controlled drift.
Does TL431QDBVT support operation above 100°C?
Yes, TL431QDBVT is explicitly rated for continuous operation from −40°C to +125°C (Q-grade). Its thermal specifications - including 150°C maximum junction temperature and validated electrical characteristics in Section 6.7 - confirm reliable functionality in under-hood automotive and high-ambient industrial environments. Derating guidelines in Section 6.4 apply for sustained 125°C ambient conditions.
What is the minimum cathode current required for regulation in TL431QDBVT?
The TL431QDBVT requires a minimum cathode current of 0.4 mA to maintain regulation, per Section 6.7 (Electrical Characteristics, TL431Q/TL432Q). This value is consistent across all Q-grade variants and ensures stable operation even with high-value feedback resistors. Below 0.4 mA, the device exits regulation and reference voltage collapses.
Can TL431QDBVT replace a standard Zener diode in power supply designs?
Yes, TL431QDBVT is engineered as a direct, high-performance replacement for Zener diodes in shunt regulation applications. Its active error amplifier delivers sharper turn-on, lower dynamic impedance (0.2 Ω vs. typical Zener's 5–20 Ω), and far better temperature stability (14 mV drift vs. >50 mV for 5% Zeners). TI's datasheet explicitly positions TL431QDBVT for "excellent replacements for Zener diodes" in on-board regulation and switching supplies.
What package type does TL431QDBVT use and what are its dimensions?
TL431QDBVT uses the SOT-23-3 package with nominal body dimensions of 2.90 mm × 1.30 mm, as specified in the Device Information table (page 2) of the TI SLVS543S datasheet. This compact, surface-mount package supports automated assembly and offers thermal resistance (RθJA) of 206°C/W - suitable for moderate-power regulation in space-constrained industrial and automotive PCB layouts.
TL431QDBVT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- SC-74A, SOT-753
- 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:
- ±2.2%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 1 mA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
TL431QDBVT FAQ
1.How can I place an order for TL431QDBVT through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431QDBVT 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 TL431QDBVT reliable?
The price and inventory of TL431QDBVT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431QDBVT is usually 5 days.
3.What payment methods are accepted for TL431QDBVT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431QDBVT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431QDBVT?
TL431QDBVT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431QDBVT 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 TL431QDBVT?
For technical support, including TL431QDBVT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431QDBVT requirements.
6.How does Aetrix verify that TL431QDBVT is sourced from the original manufacturer or authorized distributors?
All TL431QDBVT 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 TL431QDBVT meets industry standards.
7.What is the process for return or replacement of TL431QDBVT?
All TL431QDBVT units undergo pre-shipment inspection (PSI). If there is an issue with TL431QDBVT, 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 TL431QDBVT part is unused and in its original packaging.
Return procedure for TL431QDBVT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431QDBVT Tags
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TL431AIDBZR
Texas Instruments
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TL431BQDBZR
Texas Instruments
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AN431AN-ATRG1
Diodes Incorporated
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LM4040CYM3-2.5-TR
Microchip Technology
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LM4040CYM3-4.1-TR
Microchip Technology
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LM4040EIM3-2.5/NOPB
Texas Instruments
-
AZ431LBNTR-G1
Diodes Incorporated
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LM4040D20IDBZR
Texas Instruments
-
LM4041DIM3-ADJ/NOPB
Texas Instruments
-
LM4040DIM3X-2.5/NOPB
Texas Instruments
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LM4040DIM3-2.5/NOPB
Texas Instruments
-
AZ431LANTR-G1
Diodes Incorporated
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