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Texas Instruments TL431QPKG3
- Part No.:
- TL431QPKG3
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-243AA
- Datasheet:
-
TL431QPKG3.pdf
- Description:
- IC VREF SHUNT ADJ 2.2% SOT89-3
- Quantity:
- Payment:
- Shipping:
Inventory:12,140
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Product details
Overview
TL431QPKG3 from Texas Instruments is a precision programmable shunt voltage reference in SOT-89 package, delivering 2.495 V nominal reference voltage with ±0.5% initial tolerance (B-grade), 14 mV max 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 requiring high-accuracy regulation.
For engineers reviewing the TL431QPKG3 datasheet, TL431QPKG3 pinout, TL431QPKG3 application, or TL431QPKG3 equivalent, key selection criteria include automotive-grade temperature range (−40°C to 125°C), low output noise, sink-current capability up to 100 mA, and compatibility with standard resistor-divider feedback networks for output voltages from 2.5 V to 36 V.
Technical Context
The TL431QPKG3 implements a three-terminal adjustable shunt regulator architecture with an internal precision op-amp and NPN transistor output stage. Its reference input (REF) compares against an internal 2.495 V bandgap, controlling cathode current flow between CATHODE and ANODE terminals to maintain regulation.
It features sharp turn-on characteristics and stable operation across wide load and line variations, enabling direct replacement of Zener diodes in feedback loops of flyback, forward, and LLC converters - particularly where thermal stability and low dynamic impedance are critical for loop compensation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V ±0.5% at 25°C - sets precise feedback threshold for output voltage programming via external resistors |
| Temp Range | −40°C to +125°C - qualified for under-hood automotive and industrial ambient environments |
| Temp Drift | ≤14 mV over full range - ensures <±0.056% output variation across temperature, critical for stable closed-loop control |
| Dynamic Impedance | 0.2 Ω typical - minimizes AC error injection into feedback node, improving PSRR and transient response |
| Sink Current | 1 mA to 100 mA - supports direct drive of optocoupler LEDs or error amplifier inputs without buffering |
| Output Noise | Low - enables clean regulation in noise-sensitive analog power domains (e.g., servo drive references) |
| Min Cathode Current | 0.4 mA - defines lowest usable load for reliable regulation; impacts light-load efficiency in standby modes |
Pinout & Package
SOT-89 package (3-pin, 4.5 mm × 2.5 mm × 1.6 mm body), thermally enhanced with exposed tab connected to ANODE for PCB heat sinking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| REF (Pin 1) | Reference Input | High-impedance input sensing voltage divider output; triggers regulation when ≥2.495 V relative to ANODE |
| ANODE (Pin 2) | Common Return | Ground reference for REF and cathode current return path; electrically tied to exposed thermal pad |
| CATHODE (Pin 3) | Shunt Output | Sinks regulated current from supply rail into ANODE; forms feedback node in isolated converter topologies |
Key Features
| Feature | Design Value |
|---|---|
| 0.5% Initial Accuracy (B Grade) | Reduces need for post-production trimming in high-volume power supply manufacturing |
| 14 mV Max Temp Drift | Enables single-resistor feedback design without temperature-compensation circuitry in automotive modules |
| 0.2 Ω Dynamic Impedance | Permits use with high-ESR output capacitors while maintaining phase margin in voltage-mode controllers |
| 100 mA Sink Capability | Drives PC817/PC818 optocouplers directly in flyback feedback paths without external transistor |
| −40°C to +125°C Operation | Supports AEC-Q100-compliant designs for engine control units and traction inverters |
Applications
| Rack Server Power | Industrial AC/DC |
|---|---|
Use Scenario: Secondary-side voltage regulation in 48 V–12 V isolated buck-derived server PSU modules. IC Role / Device Role / Timing Role: Precision shunt reference in optocoupler-coupled feedback loop, setting 12 V output with ±1% accuracy across line/load/temp. Use Value: Enables compliance with PMBus v1.3 voltage reporting tolerances and reduces calibration overhead in volume production. | Use Scenario: Output voltage stabilization in DIN-rail mounted 24 V/48 V industrial power supplies. IC Role / Device Role / Timing Role: Adjustable shunt regulator providing stable reference for TL494 or UC384x-based PWM controllers. Use Value: Maintains output regulation within ±2% over 0–100% load and −25°C–+70°C ambient without auxiliary bias winding. |
| AC Inverter & VF Drives | Servo Drive Control Module |
Use Scenario: DC bus voltage monitoring and overvoltage protection reference in 3-phase IGBT gate driver power rails. IC Role / Device Role / Timing Role: High-stability reference for comparator-based OVLO circuits detecting >800 V bus faults. Use Value: Eliminates drift-induced false trips during motor regenerative braking events at elevated temperatures. | Use Scenario: Feedback reference for dual-loop (current + velocity) control power stages in CNC motion controllers. IC Role / Device Role / Timing Role: Low-noise voltage reference for DAC output buffering and ADC reference scaling in analog signal chains. Use Value: Limits position error accumulation to <0.05% FS over 10,000-hour continuous operation at 85°C ambient. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BQDBVR | SOT-23-3 package; identical electrical specs but smaller footprint and lower thermal mass | Better suited for space-constrained consumer adapters; reduced thermal derating above 60°C ambient | Select when board area is critical and thermal management allows ≤70°C junction rise |
| MAX6008AEUR+T | Fixed 2.5 V output; 0.2% initial accuracy; 20 ppm/°C tempco; 10 µA quiescent current | Not adjustable; requires redesign of feedback network; superior accuracy but no voltage flexibility | Choose only if fixed 2.5 V suffices and sub-0.2% tolerance justifies cost premium and layout change |
Compared with TL431BQDBVR and MAX6008AEUR+T, TL431QPKG3 offers optimal balance of adjustability (2.5–36 V), automotive temperature rating, and thermal performance in medium-power industrial systems - especially where SOT-89's copper tab enables >1 W dissipation without heatsink.
Availability
TL431QPKG3 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 product lifecycles.
Supply support for TL431QPKG3 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 designing analog ICs, embedded processors, and system solutions for industrial, automotive, and communications markets.
The TL431 product line delivers precision programmable shunt references optimized for feedback-loop accuracy and thermal stability in isolated switching power supplies and safety-critical regulation circuits.
FAQ
What is the reference voltage tolerance of TL431QPKG3 at 25°C?
The TL431QPKG3 has a reference voltage tolerance of ±0.5% at 25°C, corresponding to the B-grade specification. This means its nominal 2.495 V reference falls within 2.483 V to 2.507 V at room temperature, enabling high-accuracy output programming in TL431QPKG3-based power supplies without calibration.
Does TL431QPKG3 support operation beyond 100°C ambient?
Yes, TL431QPKG3 is rated for operation from −40°C to +125°C ambient temperature. Its Q-temp qualification ensures stable regulation and guaranteed parameters across this full range, making it suitable for under-hood automotive applications and high-temperature industrial enclosures where standard commercial-grade references fail.
Can TL431QPKG3 replace a Zener diode in feedback circuits?
Yes, TL431QPKG3 is explicitly designed as a precision replacement for Zener diodes in feedback networks. With sharp turn-on, low dynamic impedance (0.2 Ω), and adjustable output (2.5 V to 36 V), TL431QPKG3 provides superior accuracy, temperature stability, and sink-current capability compared to discrete Zeners in TL431QPKG3-based SMPS designs.
What is the minimum cathode current required for regulation in TL431QPKG3?
The TL431QPKG3 requires a minimum cathode current of 0.4 mA to maintain regulation. This value is specified across the full temperature range and ensures reliable startup and light-load operation in TL431QPKG3-configured power supplies, including those with high-value feedback resistors or low-power optocouplers.
How does the SOT-89 package of TL431QPKG3 improve thermal performance?
The SOT-89 package of TL431QPKG3 features an exposed thermal pad electrically connected to the ANODE terminal, enabling direct PCB copper pour attachment. This reduces thermal resistance (RθJA = 52°C/W) and allows safe dissipation of up to 1.2 W at 25°C ambient - significantly enhancing reliability in TL431QPKG3-based high-current feedback paths.
TL431QPKG3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-243AA
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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-89-3
TL431QPKG3 FAQ
1.How can I place an order for TL431QPKG3 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431QPKG3 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 TL431QPKG3 reliable?
The price and inventory of TL431QPKG3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431QPKG3 is usually 5 days.
3.What payment methods are accepted for TL431QPKG3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431QPKG3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431QPKG3?
TL431QPKG3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431QPKG3 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 TL431QPKG3?
For technical support, including TL431QPKG3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431QPKG3 requirements.
6.How does Aetrix verify that TL431QPKG3 is sourced from the original manufacturer or authorized distributors?
All TL431QPKG3 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 TL431QPKG3 meets industry standards.
7.What is the process for return or replacement of TL431QPKG3?
All TL431QPKG3 units undergo pre-shipment inspection (PSI). If there is an issue with TL431QPKG3, 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 TL431QPKG3 part is unused and in its original packaging.
Return procedure for TL431QPKG3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431QPKG3 Tags
-
TL431AIDBZR
Texas Instruments
-
TL431BQDBZR
Texas Instruments
-
AN431AN-ATRG1
Diodes Incorporated
-
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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