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Texas Instruments TL431BQLPM
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- Part No.:
- TL431BQLPM
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
TL431BQLPM.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:2,061
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Product details
Overview
TL431BQLPM 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, 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 TL431BQLPM datasheet, TL431BQLPM pinout, TL431BQLPM application, or TL431BQLPM equivalent, key selection criteria include its Q-temp automotive-grade temperature rating, B-grade accuracy, SOT-23-3 package footprint, and shunt regulator topology for feedback loop stabilization in isolated DC-DC converters and voltage monitoring circuits.
Technical Context
The TL431BQLPM implements a three-terminal adjustable shunt regulator architecture with an internal error amplifier, reference voltage cell, and output transistor. Its sharp turn-on characteristic and low 0.2 Ω dynamic impedance enable stable regulation across wide load and line variations without external compensation in many configurations.
It operates as a voltage-controlled current sink: when the REF pin voltage exceeds 2.495 V (typ), the cathode-anode path conducts to maintain regulation. The device requires no external power supply - all bias is derived from the cathode current - making it ideal for secondary-side feedback in flyback and forward converters.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.483–2.507 V at 25°C (B-grade, ±0.5% tolerance) - sets precise feedback threshold for power supply regulation loops. |
| Temperature Range | −40°C to +125°C (Q-grade) - qualified for under-hood automotive and industrial environments requiring extended thermal stability. |
| Dynamic Impedance | 0.2 Ω typical (≤0.5 Ω max) - ensures minimal output voltage deviation under fast load transients in closed-loop systems. |
| Sink Current Range | 1 mA to 100 mA - supports direct interface with optocoupler LEDs and high-gain error amplifiers without buffering. |
| Reference Input Current | 2–4 µA - enables high-impedance voltage divider networks (e.g., 100 kΩ/10 kΩ) with negligible loading error. |
| Output Voltage Range | Adjustable from 2.5 V to 36 V - configured via two external resistors, enabling flexible feedback design across multiple output rails. |
| Temp Drift (VIdev) | 14–34 mV over full temperature range - verified stability for applications demanding <50 ppm/°C effective drift performance. |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm body size) with gull-wing leads; thermally enhanced for surface-mount assembly on compact PCBs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1: Cathode (K) | Current sink output terminal | Connects to switched node of power stage (e.g., optocoupler anode or error amp input); carries full regulation current. |
| Pin 2: Anode (A) | Common return/reference ground | Typically tied to system ground or power supply return; defines voltage reference point for REF pin measurement. |
| Pin 3: Reference (REF) | High-impedance sensing input | Monitors divided output voltage; triggers conduction when >2.495 V; draws only 2–4 µA, minimizing divider power loss. |
Key Features
| Feature | Design Value |
|---|---|
| 0.5% Initial Accuracy (B Grade) | Reduces need for post-manufacturing calibration in precision power supplies and battery management references. |
| −40°C to +125°C Operation (Q Grade) | Enables use in automotive engine control units, industrial motor drives, and outdoor-rated power infrastructure. |
| 0.2 Ω Dynamic Impedance | Maintains tight output regulation during rapid load steps - critical for digital load transient response in server PSUs. |
| 1–100 mA Sink Capability | Directly drives standard PC817/PC817x optocouplers and supports multi-output regulation with single reference. |
| Low 2–4 µA Reference Current | Permits use of high-value resistor dividers (e.g., 1 MΩ/100 kΩ), reducing standby power consumption in energy-efficient designs. |
Applications
| Rack Server Power | Industrial AC/DC |
|---|---|
|
Use Scenario: Secondary-side voltage feedback in isolated 48 V–12 V DC-DC converters for telecom/datacom power shelves. IC Role / Device Role / Timing Role: Shunt reference providing precise 12 V output regulation via optocoupler-coupled error signal to primary controller. Use Value: 0.5% reference accuracy and 0.2 Ω impedance ensure ±0.5% output tolerance across line/load/temperature - meeting ATCA and NEBS compliance. |
Use Scenario: Output voltage sensing in 3 kW industrial AC/DC front-end supplies with active PFC and LLC resonant stages. IC Role / Device Role / Timing Role: Programmable reference setting regulated 24 V and 5 V auxiliary rails through resistor-divider networks. Use Value: Q-temp rating guarantees stable operation at 85°C ambient inside enclosed cabinets; low input current minimizes heat generation in sealed enclosures. |
| AC Inverter & VF Drives | Servo Drive Control Module |
|
Use Scenario: DC bus voltage monitoring and overvoltage protection threshold generation in 3-phase VFDs. IC Role / Device Role / Timing Role: Precision shunt reference feeding comparator inputs to trigger shutdown when bus exceeds 800 V. Use Value: 34 mV total temp drift ensures trip point remains within ±0.5% over −40°C to +125°C junction - preventing nuisance trips or delayed fault response. |
Use Scenario: Feedback reference for analog current loop outputs (e.g., 4–20 mA) in motion controller I/O modules. IC Role / Device Role / Timing Role: Stable 2.5 V reference source for DAC output scaling and current sense amplifier offset calibration. Use Value: Low noise and 0.2 Ω impedance prevent gain error drift in precision analog signal chains used for torque/current command fidelity. |
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 0.5% B-tolerance but narrower temp range; SOT-23-3 package identical. | Limited to commercial-temperature applications (e.g., consumer adapters, non-enclosed lab supplies). | Select when cost sensitivity outweighs extended temperature needs and ambient stays below 70°C. |
| TLVH431QDBVR | Lower 1.24 V reference (not adjustable to 2.5 V+), Q-temp rated, 1% initial accuracy, higher 3 µA input current. | Used where low-voltage reference (<2 V) is required; unsuitable for standard 2.5–36 V adjustment range. | Choose only for sub-2 V feedback paths; not a functional replacement for TL431BQLPM's 2.5 V base reference. |
Compared with TL431CDBVR, TL431BQLPM provides guaranteed operation at −40°C and +125°C - essential for automotive and industrial deployments - while TLVH431QDBVR trades adjustable range and accuracy for ultra-low reference voltage, limiting its use to niche low-voltage sensing roles.
Availability
TL431BQLPM is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, and servo drive control module designs requiring stable component supply with automotive-grade temperature resilience and precision voltage reference performance.
Supply support for TL431BQLPM 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 over 50 years of innovation in precision analog ICs.
The TL431 family was designed as a pin-compatible, adjustable alternative to Zener diodes - targeting high-accuracy, low-drift voltage references for power supply feedback, voltage monitoring, and programmable threshold detection.
FAQ
What is the reference voltage tolerance of TL431BQLPM at 25°C?
The TL431BQLPM has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 2.483 V to 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-temp operating range when measured under standard test conditions (VKA = Vref, IKA = 10 mA). The TL431BQLPM maintains this tolerance without calibration.
Does TL431BQLPM require an external power supply to operate?
No, the TL431BQLPM does not require an external power supply. It operates as a self-biased shunt regulator - all internal circuitry is powered by the cathode current flowing through the device. As long as the cathode voltage exceeds the reference voltage (≥2.5 V) and minimum cathode current (≥0.4 mA) is supplied, the TL431BQLPM functions autonomously without auxiliary rails or bias networks.
What is the maximum cathode voltage rating for TL431BQLPM?
The absolute maximum cathode voltage (VKA) for TL431BQLPM is 37 V, as stated in Section 6.1 of the TI SLVS543S datasheet. For reliable operation, the recommended maximum is 36 V. Exceeding 37 V risks permanent damage. This rating applies with respect to the anode pin, which serves as the reference ground node in standard configurations.
Can TL431BQLPM be used in place of a Zener diode?
Yes, the TL431BQLPM is explicitly designed as a superior replacement for Zener diodes in voltage reference and regulation applications. Its 0.2 Ω dynamic impedance, sharp turn-on, and 0.5% initial accuracy outperform typical Zeners - especially in adjustable configurations where two resistors set the output from 2.5 V to 36 V. Unlike Zeners, TL431BQLPM maintains stable performance across temperature and current variations.
What package type is used for TL431BQLPM?
The TL431BQLPM uses the SOT-23-3 package (body size 2.90 mm × 1.30 mm), confirmed in TI's Device Information table and orderable addendum. This 3-pin gull-wing surface-mount package is RoHS-compliant, thermally optimized for PCB heat dissipation, and compatible with standard reflow processes - distinct from SOIC, PDIP, or SOT-23-5 variants in the TL431 family.
TL431BQLPM Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Series:
- -
- Packaging:
- Cut Tape (CT)
- 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
TL431BQLPM FAQ
1.How can I place an order for TL431BQLPM through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431BQLPM 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 TL431BQLPM reliable?
The price and inventory of TL431BQLPM are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431BQLPM is usually 5 days.
3.What payment methods are accepted for TL431BQLPM?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431BQLPM transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431BQLPM?
TL431BQLPM orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431BQLPM 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 TL431BQLPM?
For technical support, including TL431BQLPM datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431BQLPM requirements.
6.How does Aetrix verify that TL431BQLPM is sourced from the original manufacturer or authorized distributors?
All TL431BQLPM 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 TL431BQLPM meets industry standards.
7.What is the process for return or replacement of TL431BQLPM?
All TL431BQLPM units undergo pre-shipment inspection (PSI). If there is an issue with TL431BQLPM, 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 TL431BQLPM part is unused and in its original packaging.
Return procedure for TL431BQLPM:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431BQLPM Tags
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TL431AIDBZR
Texas Instruments
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TL431BQDBZR
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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
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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
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AZ431LANTR-G1
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