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Texas Instruments TL431IDBZT
- Part No.:
- TL431IDBZT
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TL431IDBZT.pdf
- Description:
- IC VREF SHUNT ADJ 2.2% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:5,538
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Product details
Overview
TL431IDBZT 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 (B-grade), 0.2 Ω typical dynamic impedance, and operation across −40°C to 85°C. It replaces Zener diodes in feedback loops of isolated DC/DC converters, AC/DC adapters, and industrial power supplies.
For engineers reviewing the TL431IDBZT datasheet, TL431IDBZT pinout, TL431IDBZT application, or TL431IDBZT equivalent, key selection criteria include temperature drift (14 mV over −40°C to 85°C), cathode current range (1–100 mA), low output noise, and compatibility with standard resistor-divider programming for adjustable outputs from 2.5 V to 36 V.
Technical Context
The TL431IDBZT implements a high-gain transconductance amplifier with internal 2.495 V bandgap reference, comparing REF pin voltage to Vref and sinking cathode current to maintain regulation. Its sharp turn-on characteristic and low output impedance enable stable closed-loop control in switching regulator feedback paths.
Designed for I-grade (−40°C to 85°C) operation, it features 14 mV max reference voltage deviation over full temperature range, 2–4 µA reference input current, and 0.4–0.7 mA minimum cathode current for regulation-enabling reliable performance in industrial AC/DC and servo drive control modules.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V nominal; ±0.5% initial accuracy at 25°C enables precise feedback setpoint in power supply designs |
| Temperature Range | −40°C to +85°C; supports industrial ambient conditions without derating |
| Dynamic Impedance | 0.2 Ω typical; ensures minimal output voltage shift under load transients in regulation circuits |
| Cathode Current Range | 1 mA to 100 mA; accommodates both light-load biasing and high-current error amplification |
| Reference Input Current | 2–4 µA; allows use of high-value divider resistors to minimize power loss in feedback networks |
| Output Noise | Low broadband noise; critical for stable regulation in low-noise analog power systems |
| Min Cathode Current | 0.4–0.7 mA; defines lowest operating point before regulation dropout in shunt mode |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm), surface-mount, thermally efficient for power regulation applications.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1: REF | Reference input | High-impedance threshold node; connected to resistor divider midpoint to sense output voltage |
| Pin 2: CATHODE | Current sink output | Drives optocoupler LED or error amplifier input; sinks up to 100 mA to regulate system output |
| Pin 3: ANODE | Common return | Typically tied to system ground or power supply return; establishes reference potential for REF and CATHODE |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output voltage | Programmable from 2.5 V to 36 V using two external resistors-enables single BOM for multiple output rails |
| Sharp turn-on characteristic | Enables clean transition into regulation without hysteresis-critical for stable feedback in flyback converters |
| Low output impedance | 0.2 Ω typical dynamic impedance minimizes voltage droop during transient load steps |
| Low reference input current | 2–4 µA allows >1 MΩ feedback dividers-reducing power loss and thermal drift in high-voltage supplies |
| Industrial temperature grade | Rated for −40°C to +85°C operation-qualified for use in rack servers, servo drives, and industrial AC/DC systems |
Applications
| AC/DC Power Adapter | Rack Server PSU |
|---|---|
Use Scenario: Secondary-side voltage regulation in isolated 12 V/19 V notebook PC adapters. IC Role / Device Role / Timing Role: Shunt reference in optocoupler feedback loop to maintain tight output voltage accuracy across line/load/temperature. Use Value: ±0.5% initial tolerance and 14 mV temp drift ensure <±1% total output variation-meeting USB PD and OEM adapter specs. | Use Scenario: Output voltage sensing and regulation in multi-rail 48 V input server power supplies. IC Role / Device Role / Timing Role: Precision reference for digital PWM controller feedback, enabling dynamic voltage scaling and telemetry. Use Value: Low 0.2 Ω dynamic impedance maintains regulation stability under rapid load transients common in CPU/GPU power delivery. |
| Servo Drive Control | Industrial Inverter |
Use Scenario: Feedback reference for isolated gate driver bias supplies and motor current sensing amplifiers. IC Role / Device Role / Timing Role: Stable voltage reference for analog signal conditioning circuitry requiring low drift and high PSRR. Use Value: 2–4 µA reference current enables high-resistance bias networks-reducing heat generation in compact enclosed drives. | Use Scenario: Voltage monitoring and protection circuitry in variable-frequency AC inverters for HVAC and pumps. IC Role / Device Role / Timing Role: Programmable overvoltage detection threshold via resistor divider, triggering shutdown logic. Use Value: Adjustable 2.5–36 V range allows single TL431IDBZT design to cover multiple DC bus voltage classes (e.g., 300 V, 600 V, 1000 V systems). |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431CDBZR | Same SOT-23-3 package but C-grade (0°C to 70°C, ±2% initial tolerance) | Limited to commercial-temperature environments; unsuitable for industrial ambient | Select only for cost-sensitive, non-industrial applications where wider tolerance and narrower temp range are acceptable |
| TLVH431IDBZR | Lower 1.24 V reference voltage, 600 mV lower headroom; same B-grade tolerance and −40°C to 85°C rating | Better suited for low-voltage rails (<5 V); not drop-in for 12 V+ feedback loops | Choose when designing sub-5 V regulated outputs or needing reduced cathode voltage overhead |
Compared with TL431CDBZR and TLVH431IDBZR, TL431IDBZT uniquely balances industrial temperature capability, tight 0.5% initial accuracy, and 2.495 V reference-making it optimal for high-reliability AC/DC and motor control feedback where precision and ambient robustness are co-required.
Availability
TL431IDBZT is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, and servo drive control module applications requiring stable component supply and long-term production continuity.
Supply support for TL431IDBZT 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 focused on analog and embedded processing technologies, serving industrial, automotive, and communications markets with high-reliability components.
TL431IDBZT belongs to TI's precision voltage reference product line, engineered specifically for feedback regulation in isolated power supplies and industrial control systems where accuracy, stability, and temperature resilience are critical.
FAQ
What is the reference voltage tolerance of TL431IDBZT at 25°C?
The TL431IDBZT has a reference voltage tolerance of ±0.5% at 25°C, corresponding to its B-grade specification. This means the nominal 2.495 V reference falls within 2.483 V to 2.507 V at room temperature, enabling high-accuracy feedback in regulated power supplies. This tolerance is confirmed in TI's SLVS543S datasheet Section 6.11 for TL431BI devices.
Can TL431IDBZT replace a Zener diode in feedback circuits?
Yes, TL431IDBZT is explicitly designed as a superior replacement for Zener diodes in feedback applications. Its active transconductance amplifier architecture delivers sharper turn-on, lower dynamic impedance (0.2 Ω vs. typical Zener's 5–50 Ω), and programmable output (2.5 V to 36 V), making it ideal for optocoupler-based isolation in flyback and forward converters. The TL431IDBZT datasheet confirms this use case in Section 3.
What is the operating temperature range of TL431IDBZT?
TL431IDBZT is rated for operation from −40°C to +85°C, matching the I-grade specification defined in TI's device nomenclature. This industrial temperature range is validated across all electrical characteristics in Sections 6.6 and 6.9 of the SLVS543S datasheet, ensuring stable regulation in demanding environments like servo drives and AC inverters.
How does TL431IDBZT achieve low output impedance?
TL431IDBZT achieves 0.2 Ω typical dynamic impedance through an integrated high-gain transconductance amplifier driving the cathode output stage. This active regulation-unlike passive Zener behavior-maintains near-constant voltage under varying cathode current (1–100 mA), minimizing output deviation during load transients. Measured per Figure 6-12 in the datasheet, impedance remains below 0.5 Ω up to 100 kHz.
What are the absolute maximum ratings for TL431IDBZT cathode voltage and current?
The absolute maximum cathode voltage (VKA) for TL431IDBZT is 37 V, and continuous cathode current (IKA) ranges from −100 mA to +150 mA, per Section 6.1 of the SLVS543S datasheet. For reliable operation, recommended conditions limit VKA to 36 V and IKA to 1–100 mA. Exceeding these values risks permanent damage or accelerated parametric drift.
TL431IDBZT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- 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:
- ±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 ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
TL431IDBZT FAQ
1.How can I place an order for TL431IDBZT through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431IDBZT 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 TL431IDBZT reliable?
The price and inventory of TL431IDBZT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431IDBZT is usually 5 days.
3.What payment methods are accepted for TL431IDBZT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431IDBZT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431IDBZT?
TL431IDBZT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431IDBZT 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 TL431IDBZT?
For technical support, including TL431IDBZT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431IDBZT requirements.
6.How does Aetrix verify that TL431IDBZT is sourced from the original manufacturer or authorized distributors?
All TL431IDBZT 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 TL431IDBZT meets industry standards.
7.What is the process for return or replacement of TL431IDBZT?
All TL431IDBZT units undergo pre-shipment inspection (PSI). If there is an issue with TL431IDBZT, 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 TL431IDBZT part is unused and in its original packaging.
Return procedure for TL431IDBZT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431IDBZT 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
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AZ431LANTR-G1
Diodes Incorporated
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