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Texas Instruments TL431BCLPM
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- Part No.:
- TL431BCLPM
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
TL431BCLPM.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:2,381
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Product details
Overview
TL431BCLPM from Texas Instruments is a precision programmable shunt voltage reference IC with 0.5% initial tolerance at 25°C, 2.483–2.507 V reference voltage, and operation across –40°C to 125°C (Q-grade). It delivers 1–100 mA sink current, features 0.2 Ω typical dynamic impedance, and serves as a Zener diode replacement in secondary-side regulation of flyback SMPSs.
For engineers reviewing the TL431BCLPM datasheet, TL431BCLPM pinout, TL431BCLPM application, or TL431BCLPM equivalent, key selection criteria include its Q-grade temperature range, B-grade accuracy, SOT-23-3 package footprint, cathode-anode-reference terminal configuration, and low 14 mV max reference voltage drift over full temperature range.
Technical Context
The TL431BCLPM implements a three-terminal adjustable shunt regulator architecture with an internal error amplifier, reference, and output transistor. Its sharp turn-on characteristic and 0.2 Ω dynamic impedance enable stable closed-loop feedback in isolated power supplies.
It operates with external resistor dividers to set output voltage from 2.5 V to 36 V, requires ≥0.4 mA minimum cathode current for regulation, and maintains <0.5 µA off-state cathode leakage at 36 V cathode-anode voltage.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Vref | 2.483–2.507 V at 25°C - defines precise regulation threshold for feedback networks |
| Initial Tolerance | ±0.5% (B grade) - enables high-accuracy voltage setting without trimming |
| Temp Range | –40°C to +125°C (Q grade) - qualified for automotive and industrial under-hood applications |
| VKA Max | 36 V - supports wide-range output adjustment in isolated DC/DC converters |
| IKA Range | 1–100 mA sink capability - sufficient for optocoupler LED drive and direct load regulation |
| VI(dev) | ≤14 mV over full temperature range - ensures stable reference despite ambient thermal variation |
| Dynamic Impedance | 0.2 Ω typical - minimizes output voltage perturbation during transient load changes |
| Iref | 2–4 µA - ultra-low reference input current reduces divider network power loss and bias error |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm body), surface-mount, lead-free, RoHS-compliant. Pin 1 = Cathode, Pin 2 = Anode, Pin 3 = Reference (REF).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Pin 1) | Shunt current output node | Connects to feedback point (e.g., optocoupler anode); sinks regulated current to maintain VREF |
| Anode (Pin 2) | Common return/reference ground | Typically tied to system ground or power supply return; sets voltage reference baseline |
| Reference (Pin 3) | Threshold input | Compares divided output voltage against internal 2.5 V reference; triggers conduction when exceeded |
Key Features
| Feature | Design Value |
|---|---|
| 0.5% reference accuracy | Enables ±1% output voltage tolerance in SMPS designs without post-production calibration |
| 14 mV max Vref drift (–40°C to 125°C) | Reduces output voltage drift to <0.6% over full automotive temperature range |
| 0.2 Ω dynamic impedance | Stabilizes feedback loop response and improves PSRR in noisy power environments |
| 1–100 mA sink current | Directly drives standard optocoupler LEDs (e.g., PC817, SFH615A) without external buffer |
| 2–4 µA reference input current | Allows use of high-value resistor dividers (>1 MΩ), minimizing standby power consumption |
Applications
| Secondary-Side Regulation | Zener Diode Replacement |
|---|---|
Use Scenario: Isolated flyback converter with optocoupler-based feedback loop. IC Role / Device Role / Timing Role: Shunt reference providing precise 2.5 V threshold to control optocoupler LED current and regulate primary-side controller via feedback signal. Use Value: Enables ±1% output voltage accuracy across line, load, and temperature while eliminating need for external precision references or trimming. |
Use Scenario: Low-power voltage clamping or local reference generation in space-constrained PCBs. IC Role / Device Role / Timing Role: Adjustable shunt regulator replacing discrete Zener diodes in 2.5–36 V range with superior stability and lower impedance. Use Value: Reduces board area by >50% vs. through-hole Zeners and improves thermal stability with <14 mV total drift over –40°C to 125°C. |
| Voltage Monitoring | Comparator with Integrated Reference |
Use Scenario: Overvoltage protection circuit monitoring 12 V rail in automotive ECU. IC Role / Device Role / Timing Role: Precision threshold detector comparing scaled rail voltage against internal 2.5 V reference to trigger shutdown logic. Use Value: Eliminates external reference IC and reduces component count while maintaining ±0.5% trip-point accuracy at 125°C ambient. |
Use Scenario: Hysteresis-free level detection in battery management systems. IC Role / Device Role / Timing Role: Self-contained comparator where REF pin senses input and cathode/anode form active output stage. Use Value: Provides rail-to-rail compatible switching with <1 µs response time and no external biasing components required. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431CDBVR | Same B-grade accuracy and Q-temp range, but SOT-23-5 package with NC pins; higher thermal resistance (206°C/W vs. 206°C/W for DBZ) | Requires PCB layout change due to 5-pin footprint and different pinout; unsuitable for space-constrained 3-pin layouts | Select only if additional NC pins aid routing or thermal pad integration is needed |
| TLVH431BQDBVR | Lower 1.24 V reference voltage, 1% initial tolerance, same Q-grade temp range, SOT-23-5 package | Supports sub-2.5 V regulation (down to 1.24 V); not drop-in compatible due to different Vref and pinout | Choose when system requires <2.5 V reference or tighter Vref matching to legacy TLVH431 designs |
Compared with TL431BCLPM, TL431CDBVR retains identical electrical specs but demands PCB redesign for 5-pin layout, while TLVH431BQDBVR offers lower reference voltage at reduced accuracy-neither is pin-compatible, and both require circuit recalculations for resistor divider values and stability compensation.
Availability
TL431BCLPM is available at Aetrix Electronics and suitable for automotive power conversion, industrial SMPS design, and battery management systems requiring stable component supply with guaranteed long-term availability.
Supply support for TL431BCLPM 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 expertise in precision reference design.
The TL431 product line was engineered for high-accuracy, low-drift shunt regulation in isolated power supplies and safety-critical feedback loops, targeting automotive, industrial, and telecom applications.
FAQ
What is the reference voltage tolerance of TL431BCLPM at 25°C?
The TL431BCLPM 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 the TL431BQ electrical characteristics table and confirmed across all operating conditions in the TI SLVS543P datasheet. TL431BCLPM achieves this without external calibration.
What temperature range is TL431BCLPM rated for?
TL431BCLPM is rated for operation from –40°C to +125°C, designated as the Q-grade variant per TI's nomenclature. This is explicitly stated in the Device Comparison Table and verified in Section 7.13 (Electrical Characteristics, TL431BQ). The part is qualified for automotive under-hood and industrial high-temperature environments.
Which package does TL431BCLPM use, and what are its dimensions?
TL431BCLPM uses the SOT-23-3 (DBZ) package with nominal body dimensions of 2.90 mm × 1.30 mm. This is documented in the "Device Information" table and confirmed in the "Pin Configuration and Functions" section of the TI SLVS543P datasheet. The DBZ variant has a 3-pin configuration: Cathode–Anode–Reference.
Does TL431BCLPM support adjustable output voltages above 2.5 V?
Yes, TL431BCLPM supports adjustable output voltages from 2.5 V up to 36 V using two external resistors in a voltage divider configuration. This is defined in the "Description" section and validated in the Recommended Operating Conditions (Section 7.4), where VKA is specified from Vref to 36 V. The device regulates by sinking current through the cathode based on REF pin voltage.
What is the maximum cathode-to-anode voltage rating for TL431BCLPM?
The absolute maximum cathode-to-anode voltage (VKA) for TL431BCLPM is 37 V, with recommended operation up to 36 V. This rating is specified in Section 7.1 (Absolute Maximum Ratings) and applies across all temperature ranges. Exceeding 37 V risks permanent damage, per TI's stress-rating guidance.
TL431BCLPM Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Series:
- -
- Packaging:
- Bulk
- 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:
- ±0.5%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 600 µA
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92-3
TL431BCLPM FAQ
1.How can I place an order for TL431BCLPM through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431BCLPM 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 TL431BCLPM reliable?
The price and inventory of TL431BCLPM are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431BCLPM is usually 5 days.
3.What payment methods are accepted for TL431BCLPM?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431BCLPM transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431BCLPM?
TL431BCLPM orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431BCLPM 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 TL431BCLPM?
For technical support, including TL431BCLPM datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431BCLPM requirements.
6.How does Aetrix verify that TL431BCLPM is sourced from the original manufacturer or authorized distributors?
All TL431BCLPM 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 TL431BCLPM meets industry standards.
7.What is the process for return or replacement of TL431BCLPM?
All TL431BCLPM units undergo pre-shipment inspection (PSI). If there is an issue with TL431BCLPM, 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 TL431BCLPM part is unused and in its original packaging.
Return procedure for TL431BCLPM:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431BCLPM 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
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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
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AZ431LANTR-G1
Diodes Incorporated
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