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Texas Instruments TL431BQDBVR
- Part No.:
- TL431BQDBVR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
TL431BQDBVR.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:8,433
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Product details
Overview
TL431BQDBVR 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 at 25°C, 14–34 mV total temperature drift over −40°C to +125°C, and 0.2 Ω typical dynamic impedance. It operates as an adjustable feedback element in isolated DC/DC converters and industrial power supplies.
For engineers reviewing the TL431BQDBVR datasheet, TL431BQDBVR pinout, TL431BQDBVR application, or TL431BQDBVR equivalent, key selection criteria include automotive-grade temperature range (−40°C to 125°C), B-grade accuracy, low output noise, sink-current capability up to 100 mA, and compatibility with standard resistor-divider feedback networks.
Technical Context
The TL431BQDBVR implements a high-gain transconductance amplifier with internal 2.495 V bandgap reference, comparing REF pin voltage to Vref and modulating cathode current to maintain regulation. Its sharp turn-on characteristic and low output impedance enable stable operation in switching power supply feedback loops without external compensation in many cases.
Designed for Q-temp automotive qualification, it supports continuous cathode current from 1 mA to 100 mA across its full operating temperature range and exhibits minimal sensitivity to cathode voltage variation (−1.0 to −2.7 mV/V), ensuring robust performance under load transients and input ripple.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V ±12 mV (B grade, 25°C); sets precise feedback threshold in regulator circuits |
| Initial Tolerance | ±0.5% at 25°C; enables tight output voltage regulation without post-manufacturing trimming |
| Temp Range | −40°C to +125°C; qualified for under-hood automotive and industrial environments |
| Dynamic Impedance | 0.2 Ω typical; maintains stable reference under fast load changes in SMPS feedback paths |
| Cathode Current | 1–100 mA sink capability; supports direct drive of optocoupler LEDs in isolated flyback designs |
| Ref Input Current | 2–4 µA; minimizes divider resistor power loss and thermal drift in high-impedance networks |
| Output Noise | Low broadband noise; critical for low-noise LDOs and precision ADC references |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm), surface-mount, lead-free, RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| REF (Pin 1) | Reference input | High-impedance comparator input; connected to resistor divider midpoint for adjustable output setting |
| CATHODE (Pin 2) | Shunt current output | Sinks regulated current to adjust feedback loop; drives optocoupler LED in isolated topologies |
| ANODE (Pin 3) | Common return | Typically tied to system ground or power rail common point; defines reference potential |
Key Features
| Feature | Design Value |
|---|---|
| 0.5% reference accuracy | Enables ±1% output voltage tolerance in secondary-side regulated flyback converters without trimming |
| Automotive Q-temp rating | Guarantees operation from −40°C to +125°C junction temperature-meets AEC-Q100 stress test requirements |
| 0.2 Ω dynamic impedance | Reduces output voltage deviation during transient load steps, improving PSRR in closed-loop systems |
| 1–100 mA sink range | Directly interfaces with PC817/PC818 optocouplers without external transistor buffering |
| Low 2–4 µA reference current | Permits use of high-value feedback resistors (>1 MΩ), minimizing standby power and self-heating error |
Applications
| Rack Server Power | Industrial AC/DC |
|---|---|
Use Scenario: Secondary-side voltage sensing in 48 V input, 12 V/50 A isolated DC/DC modules for telecom servers. IC Role / Device Role / Timing Role: Adjustable shunt reference providing feedback to optocoupler-driven primary controller. Use Value: Maintains ±0.5% output regulation across temperature and line/load variations without calibration. | Use Scenario: Output voltage regulation in DIN-rail mounted 24 V/20 A industrial AC/DC power supplies. IC Role / Device Role / Timing Role: Precision voltage reference in feedback network of LLC resonant converter. Use Value: Enables compliance with IEC 62368-1 safety margins and reduces need for margin testing. |
| AC Inverter Drives | Servo Drive Control Module |
Use Scenario: DC bus voltage monitoring and overvoltage protection threshold in 3-phase VFDs. IC Role / Device Role / Timing Role: Programmable voltage comparator reference for analog fault detection circuitry. Use Value: Provides stable trip point across motor startup surges and ambient temperature swings. | Use Scenario: Isolated feedback for auxiliary 5 V/3 A bias supply powering gate drivers and MCU in servo amplifiers. IC Role / Device Role / Timing Role: Shunt reference in opto-coupled flyback feedback path. Use Value: Ensures consistent gate drive voltage despite primary-side transformer leakage and EMI. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BIDBVR | Same electrical specs but rated for −40°C to +85°C (I-temp), not Q-temp | Not qualified for under-hood automotive or extended industrial ambient conditions | Select when ambient temperature stays below 85°C and cost optimization is prioritized |
| TLVH431BQDBVR | Lower 1.24 V reference voltage; same Q-temp rating and 0.5% tolerance | Used where lower feedback voltage improves efficiency in low-output-voltage regulators | Choose for 3.3 V or 2.5 V output rails requiring tighter headroom and reduced divider losses |
Compared with TL431BIDBVR and TLVH431BQDBVR, TL431BQDBVR uniquely combines automotive-grade temperature range with 2.495 V reference and 0.5% accuracy-making it the only option among the three suitable for high-reliability 12 V/24 V isolated power supplies operating continuously at 125°C ambient.
Availability
TL431BQDBVR is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, and servo drive control module applications requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TL431BQDBVR 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 leadership in power management, signal chain, and high-reliability components.
The TL431 product line delivers precision programmable shunt references for feedback, regulation, and voltage monitoring in power conversion systems-designed specifically for automotive, industrial, and telecom infrastructure applications demanding stability and longevity.
FAQ
What is the reference voltage tolerance of TL431BQDBVR at 25°C?
The TL431BQDBVR has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 2.495 V nominal value with a range of 2.483 V to 2.507 V. This B-grade accuracy is specified in Section 6.13 of the TI datasheet SLVS543S and applies across the full Q-temp operating range. The TL431BQDBVR maintains this tolerance without calibration or trimming.
Does TL431BQDBVR support operation at 125°C ambient temperature?
Yes, TL431BQDBVR is qualified for operation from −40°C to +125°C ambient temperature (Q-temp grade), with guaranteed electrical performance across that full range. Its thermal design supports junction temperatures up to 150°C, and the device's 14–34 mV total reference voltage drift over temperature ensures stable regulation in under-hood automotive and high-ambient industrial environments.
What is the minimum cathode current required for regulation in TL431BQDBVR?
The TL431BQDBVR requires a minimum cathode current of 0.4 mA to maintain regulation, as specified in Section 6.13 of the datasheet. This low Imin enables reliable start-up and light-load regulation in high-efficiency power supplies, especially when paired with high-value feedback resistors or low-current optocouplers such as the PC817A.
Can TL431BQDBVR replace a Zener diode in feedback circuits?
Yes, TL431BQDBVR is explicitly designed as a superior replacement for Zener diodes in feedback circuits due to its sharp turn-on characteristic, 0.2 Ω dynamic impedance, and precise 2.495 V reference. Unlike Zeners, it provides stable regulation across temperature and current, eliminates Zener voltage spread, and enables adjustable outputs using two external resistors-making it ideal for isolated flyback and forward converter feedback networks.
What package type does TL431BQDBVR use, and is it RoHS-compliant?
TL431BQDBVR uses the SOT-23-3 package (2.90 mm × 1.30 mm body size) and is RoHS-compliant and lead-free. This compact surface-mount package supports automated assembly and meets IPC/JEDEC standards for moisture sensitivity level (MSL) 1, enabling reflow soldering without special handling. Pin configuration matches standard TL431 SOT-23-3 layouts per TI's DBZ package drawing.
TL431BQDBVR 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:
- ±0.5%
- 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-23-5
TL431BQDBVR FAQ
1.How can I place an order for TL431BQDBVR through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431BQDBVR 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 TL431BQDBVR reliable?
The price and inventory of TL431BQDBVR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431BQDBVR is usually 5 days.
3.What payment methods are accepted for TL431BQDBVR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431BQDBVR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431BQDBVR?
TL431BQDBVR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431BQDBVR 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 TL431BQDBVR?
For technical support, including TL431BQDBVR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431BQDBVR requirements.
6.How does Aetrix verify that TL431BQDBVR is sourced from the original manufacturer or authorized distributors?
All TL431BQDBVR 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 TL431BQDBVR meets industry standards.
7.What is the process for return or replacement of TL431BQDBVR?
All TL431BQDBVR units undergo pre-shipment inspection (PSI). If there is an issue with TL431BQDBVR, 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 TL431BQDBVR part is unused and in its original packaging.
Return procedure for TL431BQDBVR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431BQDBVR 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
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LM4040CYM3-4.1-TR
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LM4040EIM3-2.5/NOPB
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AZ431LBNTR-G1
Diodes Incorporated
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LM4040D20IDBZR
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LM4041DIM3-ADJ/NOPB
Texas Instruments
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LM4040DIM3X-2.5/NOPB
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LM4040DIM3-2.5/NOPB
Texas Instruments
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AZ431LANTR-G1
Diodes Incorporated
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