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Texas Instruments TL431AIDBZTG4
- Part No.:
- TL431AIDBZTG4
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TL431AIDBZTG4.pdf
- Description:
- IC VREF SHUNT ADJ 1% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:3,461
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Product details
Overview
TL431AIDBZTG4 from Texas Instruments is a precision programmable shunt voltage reference in SOT-23-3 package, featuring 1% initial reference voltage tolerance at 25°C, adjustable output from 2.495 V to 36 V, and operation across −40°C to 85°C. It delivers 0.2 Ω typical dynamic impedance and supports 1–100 mA sink current, widely used in feedback loops of isolated DC/DC converters and AC/DC power supplies.
For engineers reviewing the TL431AIDBZTG4 datasheet, TL431AIDBZTG4 pinout, TL431AIDBZTG4 application, or TL431AIDBZTG4 equivalent, key selection criteria include reference accuracy grade (A), thermal drift performance (14 mV over −40°C to 85°C), cathode current capability, stability with capacitive loads, and SOT-23-3 footprint compatibility in space-constrained power designs.
Technical Context
The TL431AIDBZTG4 implements a three-terminal adjustable shunt regulator architecture with an internal 2.495 V bandgap reference, error amplifier, and NPN output stage. Its sharp turn-on characteristic and low output impedance enable precise regulation without external compensation in most feedback configurations.
Designed for use in optocoupler-coupled secondary-side regulation, it operates with cathode voltage referenced to anode (ground or return path), where REF pin senses voltage divider output and controls cathode current to maintain setpoint - supporting both fixed and programmable output topologies.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V ±1% at 25°C - sets tight output tolerance in feedback networks |
| Temp Range | −40°C to +85°C - qualified for industrial-grade power supply operation |
| Dynamic Impedance | 0.2 Ω typical - ensures stable regulation under fast load transients |
| Cathode Current | 1 mA to 100 mA - supports wide range of optocoupler LED drive and shunt dissipation |
| Ref Input Current | 2–4 µA - enables high-impedance voltage divider design with minimal error |
| Output Noise | Low broadband noise - critical for low-noise feedback in audio or sensing supplies |
| Temp Drift | 14 mV max over full range - maintains <0.05%/°C effective drift in closed-loop systems |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm), surface-mount, lead-free and RoHS-compliant. Pin 1 = REF, Pin 2 = CATHODE, Pin 3 = ANODE.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| REF (Pin 1) | Reference input | Senses divided output voltage; threshold comparator input tied to internal 2.495 V reference |
| CATHODE (Pin 2) | Shunt current output | Sinks regulated current to control external pass element or optocoupler LED |
| ANODE (Pin 3) | Common return | Typically connected to system ground or return path; all voltages referenced to this node |
Key Features
| Feature | Design Value |
|---|---|
| 1% Initial Accuracy (A Grade) | Reduces output voltage calibration burden in production; eliminates need for post-manufacture trimming in many applications |
| 0.2 Ω Dynamic Impedance | Minimizes output voltage deviation during rapid load steps - essential for dynamic regulation in server PSUs |
| −40°C to +85°C Operation | Validated for industrial ambient conditions without derating; supports fanless or convection-cooled enclosures |
| Low Reference Input Current | Enables >1 MΩ divider resistors - reduces standby power and improves efficiency in no-load conditions |
| Stable with Capacitive Loads | Supports direct connection to optocoupler LEDs and small bypass caps without oscillation (per Figure 6-16/18) |
Applications
| AC/DC Power Adapter | Rack Server PSU |
|---|---|
Use Scenario: Secondary-side voltage feedback in flyback converter powering notebook adapters. IC Role / Device Role / Timing Role: Shunt reference regulating optocoupler LED current to close voltage loop across isolation barrier. Use Value: 1% accuracy ensures ±12 mV output tolerance at 12 V; low temp drift prevents thermal-induced output drift during sustained load. |
Use Scenario: Precision feedback in multi-output, digitally controlled 48 V intermediate bus converters. IC Role / Device Role / Timing Role: Programmable reference setting point for isolated auxiliary rails (e.g., 3.3 V, 5 V) via resistor network. Use Value: 0.2 Ω impedance maintains regulation stability during CPU burst loads; SOT-23-3 saves board area in dense VRM layouts. |
| Industrial Motor Drive | Uninterruptible Power Supply |
Use Scenario: Output voltage monitoring and regulation in VF inverter DC link supply. IC Role / Device Role / Timing Role: Shunt reference in feedback path of isolated auxiliary supply powering gate drivers and MCU. Use Value: −40°C to +85°C rating ensures reliable startup and operation in factory-floor environments; low Iref extends hold-up time. |
Use Scenario: Battery charging voltage regulation and backup rail supervision in line-interactive UPS. IC Role / Device Role / Timing Role: Precision reference for ADC monitoring and analog control loop in battery management subsystem. Use Value: 14 mV total temp drift enables accurate state-of-charge estimation across operating temperature; low noise avoids false fault triggers. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431CDBZR | 0°C to 70°C rating, 2% initial tolerance (standard grade) | Lower-cost option for commercial-temp consumer adapters; not suitable for extended industrial ambient | Select when cost sensitivity outweighs accuracy and temperature range requirements |
| TL431BIDBZT | 0.5% initial tolerance, same −40°C to +85°C range | Higher-accuracy replacement for tighter output specs; identical pinout and thermal behavior | Choose when system-level output tolerance demands <±5 mV at 25°C |
Compared with TL431CDBZR, TL431AIDBZTG4 offers tighter 1% tolerance and wider industrial temperature support; compared with TL431BIDBZT, it trades 0.5% accuracy for lower unit cost while retaining full thermal qualification - making it optimal for cost-sensitive industrial power designs requiring robustness without ultra-high precision.
Availability
TL431AIDBZTG4 is available at Aetrix Electronics and suitable for AC/DC power adapters, rack server PSUs, and industrial motor drives requiring stable component supply, long-term manufacturability, and consistent parametric performance across production batches.
Supply support for TL431AIDBZTG4 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 and power control ICs.
TL431AIDBZTG4 belongs to TI's precision programmable shunt reference product line, engineered for high-accuracy, low-drift voltage regulation in isolated power supply feedback paths across industrial, computing, and telecom infrastructure.
FAQ
What is the reference voltage tolerance of TL431AIDBZTG4 at 25°C?
The TL431AIDBZTG4 has a reference voltage tolerance of ±1% at 25°C, corresponding to a nominal 2.495 V output with min/max bounds of 2.470 V and 2.520 V. This A-grade accuracy is specified per TI's SLVS543S datasheet Section 6.8 and applies across the full operating temperature range when combined with its 14 mV total drift specification.
Can TL431AIDBZTG4 replace a Zener diode in feedback circuits?
Yes, TL431AIDBZTG4 is explicitly designed as a superior Zener diode replacement in feedback circuits. Its active error amplifier provides sharper turn-on, lower dynamic impedance (0.2 Ω vs typical Zener's >10 Ω), and programmable output (2.495 V to 36 V) - enabling higher accuracy, better temperature stability, and reduced part count in isolated DC/DC converters.
What is the maximum cathode current supported by TL431AIDBZTG4?
The TL431AIDBZTG4 supports a continuous cathode current range of 1 mA to 100 mA, as defined in Section 6.4 of the datasheet. At 100 mA, power dissipation must remain within thermal limits - with RθJA = 206°C/W for the SOT-23-3 package, junction temperature must be kept below 150°C under worst-case ambient conditions.
Does TL431AIDBZTG4 require external compensation for stability?
No, TL431AIDBZTG4 is internally compensated and stable with typical optocoupler-based feedback networks. Figures 6-16 and 6-18 in the datasheet confirm stability across common capacitive load ranges (up to several µF) and cathode current levels - eliminating need for external phase compensation in standard isolated power supply designs.
How does the SOT-23-3 package of TL431AIDBZTG4 impact thermal performance?
The SOT-23-3 package of TL431AIDBZTG4 has a junction-to-ambient thermal resistance (RθJA) of 206°C/W, per Section 6.3. This requires careful PCB layout - including adequate copper pour on the anode pad - to manage power dissipation. At 100 mA and 5 V cathode-anode drop, ~500 mW dissipation would raise junction temperature by ~103°C above ambient, necessitating derating above 47°C ambient.
TL431AIDBZTG4 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:
- Discontinued at Digi-Key
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 2.495V
- Voltage - Output (Max):
- 36 V
- Current - Output:
- 100 mA
- Tolerance:
- ±1%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 700 µA
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
TL431AIDBZTG4 FAQ
1.How can I place an order for TL431AIDBZTG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431AIDBZTG4 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 TL431AIDBZTG4 reliable?
The price and inventory of TL431AIDBZTG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431AIDBZTG4 is usually 5 days.
3.What payment methods are accepted for TL431AIDBZTG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431AIDBZTG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431AIDBZTG4?
TL431AIDBZTG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431AIDBZTG4 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 TL431AIDBZTG4?
For technical support, including TL431AIDBZTG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431AIDBZTG4 requirements.
6.How does Aetrix verify that TL431AIDBZTG4 is sourced from the original manufacturer or authorized distributors?
All TL431AIDBZTG4 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 TL431AIDBZTG4 meets industry standards.
7.What is the process for return or replacement of TL431AIDBZTG4?
All TL431AIDBZTG4 units undergo pre-shipment inspection (PSI). If there is an issue with TL431AIDBZTG4, 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 TL431AIDBZTG4 part is unused and in its original packaging.
Return procedure for TL431AIDBZTG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431AIDBZTG4 Tags
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TL431AIDBZR
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LM4040EIM3-2.5/NOPB
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LM4041DIM3-ADJ/NOPB
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LM4040DIM3X-2.5/NOPB
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AZ431LANTR-G1
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