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Texas Instruments TL431BQDCKR
- Part No.:
- TL431BQDCKR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 6-TSSOP, SC-88, SOT-363
- Datasheet:
-
TL431BQDCKR.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SC70-6
- Quantity:
- Payment:
- Shipping:
Inventory:1,918
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Product details
Overview
TL431BQDCKR 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 TL431BQDCKR datasheet, TL431BQDCKR pinout, TL431BQDCKR application, or TL431BQDCKR equivalent, key selection criteria include automotive-grade temperature range (−40°C to +125°C), tight 0.5% reference accuracy, low 2–4 µA reference input current, and compatibility with standard resistor-divider feedback networks for output voltage programming from 2.5 V to 36 V.
Technical Context
The TL431BQDCKR implements a three-terminal adjustable shunt regulator architecture with an internal error amplifier, reference voltage source, and NPN output stage. Its sharp turn-on characteristic and low 0.2 Ω dynamic impedance enable stable regulation without external compensation in most feedback loops.
It functions exclusively in shunt mode: cathode sinks current based on REF-to-ANODE voltage differential, requiring external resistive divider to set output voltage. The SOT-23-3 package (2.90 mm × 1.30 mm) supports high-density PCB layouts in space-constrained industrial and automotive power modules.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V (nominal); enables precise 2.5 V–36 V output programming via two external resistors |
| Initial Tolerance | ±0.5% at 25°C (B grade); ensures minimal calibration burden in production test |
| Temp Range | −40°C to +125°C (Q grade); qualified for under-hood automotive and industrial ambient conditions |
| Dynamic Impedance | 0.2 Ω typical; maintains stable regulation under fast load transients in switching PSUs |
| Cathode Current | 1 mA to 100 mA sink capability; supports direct drive of optocoupler LEDs in isolated flyback controllers |
| Ref Input Current | 2–4 µA; minimizes divider resistor power loss and thermal drift in high-impedance feedback networks |
| Temp Drift | 14–34 mV over full range; verified stability for closed-loop control in servo drives and AC inverters |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm), 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 | Sinks regulated current to maintain REF–ANODE voltage at 2.495 V; connects to primary-side feedback in isolated topologies |
| Reference (Pin 2) | Threshold input | Compares against internal 2.495 V reference; forms feedback node with external resistor divider |
| Anode (Pin 3) | Common return path | Typically tied to system ground or power supply return; defines voltage reference point for REF input |
Key Features
| Feature | Design Value |
|---|---|
| 0.5% reference accuracy | Reduces need for post-production trimming in high-volume power adapter manufacturing |
| −40°C to +125°C operation | Enables use in automotive engine control units and industrial motor drives without derating |
| 0.2 Ω dynamic impedance | Suppresses output voltage ripple in 100 kHz+ switching converters without added capacitance |
| Low 2–4 µA reference current | Permits use of >1 MΩ feedback dividers, minimizing standby power in energy-efficient designs |
| Three-terminal shunt topology | Eliminates need for external op-amp or comparator in basic voltage regulation circuits |
Applications
| Rack Server Power | Industrial AC/DC |
|---|---|
Use Scenario: Secondary-side voltage feedback in 1 kW+ telecom rectifiers with digital PMBus control. IC Role / Device Role / Timing Role: Precision shunt reference setting output voltage accuracy and load regulation. Use Value: Maintains ±0.5% output tolerance across line/load/temperature, meeting IEC 62368-1 safety margin requirements. | Use Scenario: Output voltage regulation in DIN-rail mounted 24 V/48 V industrial PSUs. IC Role / Device Role / Timing Role: Feedback element in isolated flyback or forward converter with optocoupler interface. Use Value: Enables stable regulation at 85°C ambient with <10 mV drift, avoiding thermal shutdown in enclosed enclosures. |
| AC Inverter & VF 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 protection circuitry. Use Value: Delivers repeatable 750 V DC bus trip point with <0.1% hysteresis using matched resistor network. | Use Scenario: Position loop reference scaling in multi-axis CNC motion controllers. IC Role / Device Role / Timing Role: Stable analog reference for DAC output conditioning and current sense amplifier offset nulling. Use Value: Provides <5 ppm/°C effective drift performance, preserving encoder resolution over 0–70°C operating range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BIDCKR | Same electrical specs but rated for −40°C to +85°C (I grade), not automotive Q grade | Not qualified for under-hood or extended-temperature industrial environments | Select only if ambient does not exceed 85°C and cost sensitivity outweighs temperature margin |
| TLVH431BQDBVR | Lower 1.24 V reference voltage, 1% tolerance, same Q-temp rating and SOT-23-3 package | Requires different resistor divider values; suited for sub-2.5 V output regulation | Choose when designing 1.25–12 V outputs where lower reference improves resolution and reduces divider power |
Compared with TL431BIDCKR and TLVH431BQDBVR, TL431BQDCKR uniquely combines automotive-grade temperature range, 0.5% accuracy, and 2.495 V reference-making it optimal for high-reliability isolated power supplies where both precision and thermal robustness are mandatory.
Availability
TL431BQDCKR 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 TL431BQDCKR 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 control in isolated and non-isolated power converters, targeting automotive, industrial, and computing applications demanding accuracy, stability, and long-term reliability.
FAQ
What is the reference voltage tolerance of TL431BQDCKR at 25°C?
The TL431BQDCKR 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 strictly to the TL431BQ variant in SOT-23-3 packaging. TL431BQDCKR achieves this tolerance without external calibration.
Does TL431BQDCKR support operation at −40°C to +125°C?
Yes, TL431BQDCKR is qualified for continuous operation from −40°C to +125°C (Q-grade temperature range). This is confirmed in the Device Comparison Table and Section 6.13 Electrical Characteristics of the TI datasheet. The 14–34 mV total reference voltage deviation over this range ensures stable feedback in automotive engine compartments and industrial motor drive cabinets.
What is the dynamic impedance of TL431BQDCKR and why does it matter?
TL431BQDCKR has a typical dynamic impedance of 0.2 Ω, measured at ≤1 kHz with cathode current from 1 mA to 100 mA. This low value directly determines output voltage stability under transient load changes-enabling clean regulation in high-frequency switching power supplies without additional output capacitance or compensation networks.
Can TL431BQDCKR replace a Zener diode in feedback circuits?
Yes, TL431BQDCKR is explicitly designed as a superior replacement for Zener diodes in voltage regulation applications. Its active error amplifier provides sharper turn-on, lower dynamic impedance (0.2 Ω vs typical Zener's 5–50 Ω), and tighter initial tolerance (±0.5% vs ±5% for common Zeners), making TL431BQDCKR ideal for precision feedback in isolated DC/DC converters and adjustable linear regulators.
What package type is used for TL431BQDCKR and what are its dimensions?
TL431BQDCKR uses the SOT-23-3 package with nominal body dimensions of 2.90 mm × 1.30 mm. Pin configuration is Cathode (Pin 1), Reference (Pin 2), Anode (Pin 3), as documented in Figure 5-1 of the TI datasheet SLVS543S. This compact, surface-mount package supports high-density layout in space-constrained power modules.
TL431BQDCKR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 6-TSSOP, SC-88, SOT-363
- 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:
- SC-70-6
TL431BQDCKR FAQ
1.How can I place an order for TL431BQDCKR through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431BQDCKR 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 TL431BQDCKR reliable?
The price and inventory of TL431BQDCKR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431BQDCKR is usually 5 days.
3.What payment methods are accepted for TL431BQDCKR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431BQDCKR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431BQDCKR?
TL431BQDCKR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431BQDCKR 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 TL431BQDCKR?
For technical support, including TL431BQDCKR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431BQDCKR requirements.
6.How does Aetrix verify that TL431BQDCKR is sourced from the original manufacturer or authorized distributors?
All TL431BQDCKR 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 TL431BQDCKR meets industry standards.
7.What is the process for return or replacement of TL431BQDCKR?
All TL431BQDCKR units undergo pre-shipment inspection (PSI). If there is an issue with TL431BQDCKR, 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 TL431BQDCKR part is unused and in its original packaging.
Return procedure for TL431BQDCKR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431BQDCKR Tags
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TL431AIDBZR
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TL431BQDBZR
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LM4040EIM3-2.5/NOPB
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AZ431LBNTR-G1
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LM4041DIM3-ADJ/NOPB
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LM4040DIM3X-2.5/NOPB
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LM4040DIM3-2.5/NOPB
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AZ431LANTR-G1
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