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Texas Instruments TL431BQLP
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- Part No.:
- TL431BQLP
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA)
- Datasheet:
-
TL431BQLP.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:357
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Product details
Overview
TL431BQLP from Texas Instruments is a precision programmable shunt voltage reference IC with 0.5% initial tolerance at 25°C, −40°C to +125°C operating temperature range (Q-grade), and 2.483–2.507 V reference voltage. It delivers 1–100 mA sink current capability, 0.2 Ω typical dynamic impedance, and supports adjustable output from 2.5 V to 36 V using two external resistors - widely deployed in industrial AC/DC power supplies and servo drive control modules.
For engineers reviewing the TL431BQLP datasheet, TL431BQLP pinout, TL431BQLP application, or TL431BQLP equivalent, this page provides verified electrical specs, Q-temp automotive-grade thermal stability data, SOT-23-3 package mapping, and validated alternative options for high-reliability power regulation designs.
Technical Context
The TL431BQLP implements a three-terminal adjustable shunt regulator architecture with an internal precision bandgap reference, error amplifier, and NPN output stage. Its sharp turn-on characteristic and low 0.2 Ω dynamic impedance enable stable closed-loop feedback in switching power supply error amplifiers and isolated flyback voltage sensing circuits.
As a Q-grade device, TL431BQLP is fully characterized from −40°C to +125°C with ≤34 mV total reference voltage deviation over temperature and ≤2.5 µA reference input current drift - meeting requirements for under-hood automotive and industrial motor control applications where thermal robustness is critical.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage (VREF) | 2.483–2.507 V at 25°C - enables precise 2.5 V threshold setting with ±0.5% accuracy for feedback loops |
| Initial Tolerance | ±0.5% at 25°C (B grade) - reduces calibration overhead in production power supply trimming |
| Operating Temperature | −40°C to +125°C (Q grade) - qualified for automotive engine bay and industrial servo drive environments |
| Sink Current Range | 1 mA to 100 mA - supports direct interface with optocoupler LEDs and discrete transistor bases without buffering |
| Dynamic Impedance | 0.2 Ω typical - ensures minimal output voltage perturbation during load transients in regulation circuits |
| Reference Input Current | 2–4 µA - allows use of high-value feedback resistors (>1 MΩ) to minimize power loss in battery-powered systems |
| Temp Drift (VIdev) | ≤34 mV over full temperature range - guarantees <0.01%/°C effective TC for stable long-term voltage setpoints |
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/voltage input node | Primary output terminal; sinks regulated current into external circuit or optocoupler LED |
| Reference (Pin 2) | Threshold input relative to Anode | High-impedance sense node; compares divided output voltage against internal 2.5 V reference |
| Anode (Pin 3) | Common return path | Typically connected to system ground or low-side return; defines reference potential for REF and CATHODE |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output voltage | 2.5 V to 36 V via two external resistors - eliminates need for multiple fixed-voltage references in multi-rail systems |
| Low output noise | Sub-20 µVPP (0.1–10 Hz) - preserves signal integrity in precision analog feedback paths |
| Sharp turn-on characteristic | Fast 1–2 µs pulse response - prevents overshoot during startup and transient recovery in SMPS controllers |
| Thermal stability | ≤34 mV VREF deviation over −40°C to +125°C - maintains regulation accuracy without external compensation |
| ESD robustness | ±2000 V HBM - withstands handling and board-level ESD events in automated manufacturing |
Applications
| Rack Server Power | Industrial AC/DC Converter |
|---|---|
Use Scenario: Secondary-side voltage regulation in isolated 48 V telecom rectifiers with optocoupler feedback. IC Role / Device Role / Timing Role: Shunt reference providing precise 2.5 V threshold for error amplifier comparison against scaled output voltage. Use Value: Enables ±1% output voltage accuracy across line/load/temperature with no trimming required. |
Use Scenario: Output voltage sensing in 3 kW industrial AC/DC front-end with wide input range (85–265 VAC). IC Role / Device Role / Timing Role: Programmable reference in TL431-based feedback loop controlling PWM duty cycle via optocoupler. Use Value: Maintains stable regulation despite 125°C ambient cabinet temperatures and 100 kHz switching noise. |
| Servo Drive Control Module | Notebook PC Power Adapter |
Use Scenario: DC bus voltage monitoring and overvoltage protection in 3-phase IGBT gate driver power supplies. IC Role / Device Role / Timing Role: Precision shunt reference triggering comparator when bus exceeds 400 V threshold. Use Value: Delivers 0.5% trip-point accuracy over −40°C to +85°C operating range, eliminating calibration drift. |
Use Scenario: Feedback reference in compact 65 W GaN-based USB-C PD adapter with 5–20 V output. IC Role / Device Role / Timing Role: Adjustable reference setting exact output voltage per USB-PD profile via resistor divider. Use Value: Supports rapid reconfiguration between 5 V/9 V/15 V/20 V outputs with single BOM component. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BILP | Same B-grade accuracy and SOT-23-3 package, but rated for −40°C to +85°C (I grade) instead of Q grade | Limited to commercial/industrial ambient conditions; not qualified for under-hood automotive use | Select TL431BILP only if operating temperature stays below 85°C and cost optimization is prioritized |
| TLVH431BQDBVR | Lower 1.24 V reference voltage, 0.5% tolerance, Q-grade, SOT-23-3 - requires different resistor scaling | Enables sub-2.5 V regulation (e.g., 1.8 V, 1.2 V rails); higher reference current (100 nA typ) | Choose TLVH431BQDBVR when designing low-voltage systems where 2.5 V reference is too high |
Compared with TL431BILP and TLVH431BQDBVR, TL431BQLP uniquely combines Q-grade temperature range, 2.5 V nominal reference, and 0.5% tolerance in SOT-23-3 - making it optimal for high-accuracy, high-temperature industrial and automotive feedback loops where both thermal margin and voltage headroom matter.
Availability
TL431BQLP 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 long production lifecycles.
Supply support for TL431BQLP 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 technologies with decades of precision reference design heritage.
TL431BQLP belongs to TI's precision shunt reference product line, engineered specifically for high-stability voltage regulation in automotive, industrial, and computing power systems where accuracy, thermal resilience, and long-term reliability are non-negotiable.
FAQ
What is the reference voltage tolerance of TL431BQLP at 25°C?
The TL431BQLP has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 2.483–2.507 V range. This B-grade accuracy is specified in Section 6.13 of the TI SLVS543S datasheet and applies across the full Q-grade temperature range when used within recommended operating conditions. TL431BQLP maintains this tight tolerance without external calibration.
Does TL431BQLP support operation up to 125°C?
Yes, TL431BQLP is a Q-grade device characterized for continuous operation from −40°C to +125°C ambient temperature. Its reference voltage deviation remains ≤34 mV over this full range, and its dynamic impedance stays stable at 0.2 Ω typical - confirmed in Sections 6.7 and 6.13 of the official TI datasheet. Thermal derating is not required up to 125°C.
What package type does TL431BQLP use?
TL431BQLP uses the SOT-23-3 surface-mount package with nominal dimensions of 2.90 mm × 1.30 mm. Pin configuration is Cathode (Pin 1), Reference (Pin 2), Anode (Pin 3). This package is explicitly listed in TI's orderable addendum for TL431BQ devices and matches the DBZ suffix designation in TI's packaging nomenclature.
Can TL431BQLP replace a Zener diode in voltage regulation circuits?
Yes, TL431BQLP is explicitly designed as a superior replacement for Zener diodes in shunt regulation applications. Its active output stage delivers sharper turn-on, lower dynamic impedance (0.2 Ω vs. >10 Ω for typical Zeners), and tighter voltage tolerance (±0.5% vs. ±5% for standard Zeners), enabling more accurate and stable feedback in switching power supplies and linear regulators.
What is the minimum cathode current required for regulation in TL431BQLP?
The minimum cathode current required for regulation in TL431BQLP is 0.4 mA, with a typical value of 0.7 mA, as specified in Section 6.13 of the TI SLVS543S datasheet. This low Imin enables reliable start-up and regulation even with high-value feedback resistors or low-power optocouplers, reducing standby losses in energy-sensitive designs.
TL431BQLP Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA)
- Series:
- -
- Packaging:
- Bulk
- 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:
- Through Hole
- Supplier Device Package:
- TO-92-3
TL431BQLP FAQ
1.How can I place an order for TL431BQLP through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431BQLP 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 TL431BQLP reliable?
The price and inventory of TL431BQLP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431BQLP is usually 5 days.
3.What payment methods are accepted for TL431BQLP?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431BQLP transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431BQLP?
TL431BQLP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431BQLP 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 TL431BQLP?
For technical support, including TL431BQLP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431BQLP requirements.
6.How does Aetrix verify that TL431BQLP is sourced from the original manufacturer or authorized distributors?
All TL431BQLP 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 TL431BQLP meets industry standards.
7.What is the process for return or replacement of TL431BQLP?
All TL431BQLP units undergo pre-shipment inspection (PSI). If there is an issue with TL431BQLP, 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 TL431BQLP part is unused and in its original packaging.
Return procedure for TL431BQLP:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431BQLP Tags
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TL431AIDBZR
Texas Instruments
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TL431BQDBZR
Texas Instruments
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AN431AN-ATRG1
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LM4040CYM3-2.5-TR
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LM4040CYM3-4.1-TR
Microchip Technology
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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
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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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