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Texas Instruments TL431IDBZR
- Part No.:
- TL431IDBZR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TL431IDBZR.pdf
- Description:
- IC VREF SHUNT ADJ 2.2% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:59,536
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Product details
Overview
TL431IDBZR 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 TL431IDBZR datasheet, TL431IDBZR pinout, TL431IDBZR application, or TL431IDBZR equivalent, key selection criteria include its guaranteed 0.5% reference accuracy at 25°C, thermal stability over industrial temperature range, low output noise, sink-current capability up to 100 mA, and compatibility with standard resistor-divider programming for adjustable outputs from 2.5 V to 36 V.
Technical Context
The TL431IDBZR implements an internal error amplifier and NPN transistor output stage configured as a three-terminal adjustable shunt regulator. Its REF pin senses voltage relative to ANODE, triggering cathode current sink when input exceeds Vref - enabling precise closed-loop regulation without external op-amps.
Designed for high-stability feedback paths, it features 14 mV max reference voltage deviation over −40°C to 85°C (I-grade), 2 µA to 4 µA reference input current, and stable operation with load capacitance up to 10 µF depending on cathode voltage and current conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V nominal, ±0.5% tolerance at 25°C - ensures tight setpoint accuracy in power supply feedback networks |
| Operating Temperature | −40°C to +85°C - qualified for industrial ambient environments without derating |
| Dynamic Impedance | 0.2 Ω typical - minimizes output voltage variation under changing load/sink-current conditions |
| Sink Current Range | 1 mA to 100 mA - supports direct interface with optocoupler LEDs and error amplifier outputs |
| Reference Input Current | 2–4 µA - enables high-impedance resistor-divider design without significant loading error |
| Output Noise | Low broadband noise - critical for low-noise regulation in sensitive analog subsystems |
| Max Cathode Voltage | 36 V - allows use in wide-input-range offline and telecom power applications |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm body size) with gull-wing leads; RoHS-compliant, surface-mountable, and optimized for automated assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1: Cathode (K) | Current sink output terminal | Connected to primary-side feedback node (e.g., optocoupler anode); sinks regulated current to maintain REF voltage |
| Pin 2: Anode (A) | Common reference and return path | Typically tied to system ground or secondary-side common; serves as voltage reference point for REF pin |
| Pin 3: Reference (REF) | High-impedance voltage sense input | Monitors divider output; device regulates Cathode current until REF = 2.495 V relative to Anode |
Key Features
| Feature | Design Value |
|---|---|
| 0.5% Initial Voltage Accuracy | B-grade specification guarantees ≤12.5 mV absolute error at 25°C - reduces calibration burden in production |
| Adjustable Output Range | 2.5 V to 36 V via two external resistors - eliminates need for multiple fixed-reference parts in BOM |
| Sharp Turn-On Characteristic | Fast error amplifier response enables stable regulation even with fast transient loads |
| Low Temperature Drift | 14 mV max deviation over −40°C to 85°C - maintains regulation accuracy without external compensation |
| Robust ESD Rating | ±2000 V HBM - withstands handling and board-level ESD events in industrial manufacturing |
Applications
| Rack Server Power | Industrial AC/DC Converter |
|---|---|
Use Scenario: Secondary-side voltage sensing in isolated 48 V input / 12 V output server PSU with optocoupler feedback. IC Role / Device Role / Timing Role: Precision shunt reference setting feedback threshold for TL431IDBZR-based error amplifier driving optocoupler LED. Use Value: Enables ±1% output regulation across line/load/temperature with no trimming required. |
Use Scenario: Output voltage regulation in 3-phase industrial AC/DC front-end supplying PLC I/O modules. IC Role / Device Role / Timing Role: Adjustable shunt reference in isolated flyback controller feedback loop, interfacing with TL384x PWM IC. Use Value: Supports programmable output (24 V/48 V) using same PCB layout and firmware, reducing variant count. |
| AC Inverter Drive | Notebook PC Adapter |
Use Scenario: DC bus voltage monitoring and overvoltage protection in 200–400 V AC inverter drive control board. IC Role / Device Role / Timing Role: Shunt reference feeding comparator input for fast OV shutdown; operates directly from auxiliary supply rail. Use Value: Delivers sub-10 µs response to overvoltage events due to low dynamic impedance and minimal propagation delay. |
Use Scenario: Feedback reference in compact 65 W GaN-based notebook adapter with synchronous rectification. IC Role / Device Role / Timing Role: High-accuracy shunt reference replacing discrete Zener + op-amp, minimizing component count and board area. Use Value: Achieves <0.5% load regulation and <1% line regulation while meeting CoC Tier 2 efficiency requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACDBZR | 1% initial tolerance (A-grade), otherwise identical electrical specs and SOT-23-3 package | Suitable where tighter cost control outweighs need for 0.5% accuracy; may require minor gain adjustment in feedback divider | Select TL431ACDBZR if ±1% output tolerance is acceptable and BOM cost reduction is prioritized |
| TLVH431IDBVR | Lower 1.24 V reference voltage, 1% tolerance, 6 V max cathode voltage, SOT-23-3 package | Limited to low-voltage applications (<6 V output); not interchangeable in 12 V+ systems due to voltage rating mismatch | Choose TLVH431IDBVR only for sub-6 V regulated rails where lower reference voltage simplifies divider design |
Compared with TL431ACDBZR and TLVH431IDBVR, the TL431IDBZR provides the highest initial accuracy among SOT-23-3 shunt references rated for 36 V cathode operation, making it optimal for industrial and server power designs requiring long-term stability without recalibration.
Availability
TL431IDBZR is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC converters, and AC inverter drives requiring stable component supply with full traceability and lifecycle support.
Supply support for TL431IDBZR 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, with decades of expertise in precision analog ICs and power management solutions.
The TL431 product line was designed specifically for high-accuracy, low-drift voltage reference applications in isolated power supplies, battery chargers, and industrial control systems - emphasizing robustness, programmability, and ease of integration.
FAQ
What is the reference voltage tolerance of TL431IDBZR at 25°C?
The TL431IDBZR has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a nominal 2.495 V output with a guaranteed range of 2.483 V to 2.507 V. This B-grade accuracy is specified in TI's SLVS543S datasheet Section 6.11 and enables high-precision regulation without post-manufacturing trimming. The TL431IDBZR maintains this tolerance across its full operating temperature range of −40°C to +85°C.
Can TL431IDBZR replace a Zener diode in feedback circuits?
Yes, the TL431IDBZR is explicitly designed as a superior replacement for Zener diodes in voltage regulation feedback paths. Its active error amplifier delivers sharp turn-on characteristics, 0.2 Ω dynamic impedance, and programmable output from 2.5 V to 36 V - all unattainable with passive Zeners. Unlike Zeners, TL431IDBZR provides stable performance across temperature and current, eliminating drift-related calibration issues in applications like AC/DC adapters and servo drives.
What are the absolute maximum ratings for TL431IDBZR?
The TL431IDBZR has an absolute maximum cathode voltage (VKA) of 37 V and continuous cathode current (IKA) range of −100 mA to +150 mA. Its junction temperature must not exceed 150°C, and storage temperature is rated from −65°C to +150°C. These limits are defined in Section 6.1 of the TI SLVS543S datasheet. Exceeding VKA > 36 V or IKA > 100 mA in normal operation risks reliability degradation, though brief transients within absolute max are survivable.
How does TL431IDBZR achieve stability with capacitive loads?
The TL431IDBZR exhibits conditional stability with capacitive loads: Figure 6-18 in the TI datasheet shows oscillation boundaries dependent on cathode voltage (VKA) and load capacitance (CL). At VKA = 5 V, stability is maintained up to ~1 µF; at VKA = 15 V, safe CL drops to ~0.1 µF. Designers must limit CL or add series resistance (e.g., 10–100 Ω) between cathode and capacitor to ensure phase margin - especially critical in optocoupler-driven feedback loops.
Is TL431IDBZR pin-compatible with other TL431 variants in SOT-23-3?
Yes, TL431IDBZR uses the standard TL431 SOT-23-3 pinout (Cathode–Anode–REF), matching TL431ACDBZR, TL431BIDBZR, and all TL431x-DBZ variants. Pin compatibility is confirmed in Section 5 of the TI SLVS543S datasheet, which shows identical top-view pin assignments for TL431 DBZ packages regardless of grade (A/B/standard) or temperature rating (I/Q/C). No PCB layout changes are needed when substituting within the DBZ family.
TL431IDBZR 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
TL431IDBZR FAQ
1.How can I place an order for TL431IDBZR through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431IDBZR 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 TL431IDBZR reliable?
The price and inventory of TL431IDBZR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431IDBZR is usually 5 days.
3.What payment methods are accepted for TL431IDBZR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431IDBZR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431IDBZR?
TL431IDBZR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431IDBZR 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 TL431IDBZR?
For technical support, including TL431IDBZR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431IDBZR requirements.
6.How does Aetrix verify that TL431IDBZR is sourced from the original manufacturer or authorized distributors?
All TL431IDBZR 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 TL431IDBZR meets industry standards.
7.What is the process for return or replacement of TL431IDBZR?
All TL431IDBZR units undergo pre-shipment inspection (PSI). If there is an issue with TL431IDBZR, 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 TL431IDBZR part is unused and in its original packaging.
Return procedure for TL431IDBZR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431IDBZR Tags
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