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Texas Instruments TL431IPKG3
- Part No.:
- TL431IPKG3
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-243AA
- Datasheet:
-
TL431IPKG3.pdf
- Description:
- IC VREF SHUNT ADJ 2.2% SOT89-3
- Quantity:
- Payment:
- Shipping:
Inventory:3,176
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Product details
Overview
TL431IPKG3 from Texas Instruments is a precision programmable shunt voltage reference in SOT-89 package, delivering 2.495 V nominal reference voltage with ±0.5% initial tolerance (B grade), 14 mV max temperature drift over −40°C to 125°C, and 0.2 Ω typical dynamic impedance. It operates as an adjustable feedback element in isolated DC/DC converters and linear regulators for industrial power supplies.
For engineers reviewing the TL431IPKG3 datasheet, TL431IPKG3 pinout, TL431IPKG3 application, or TL431IPKG3 equivalent, key selection criteria include its Q-grade temperature range (−40°C to 125°C), cathode current capability (1–100 mA), low output noise, and compatibility with standard resistor-divider feedback networks in flyback and forward converter topologies.
Technical Context
The TL431IPKG3 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 active output stage enable Zener diode replacement in closed-loop feedback paths.
Designed for automotive and industrial environments, it supports stable operation up to 36 V cathode-anode voltage with minimal load capacitance sensitivity-verified across SOT-89 thermal profiles (RθJA = 52°C/W) and qualified per AEC-Q100 stress test conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V ±0.5% at 25°C - sets precise feedback threshold for output voltage regulation |
| Temp Range | −40°C to +125°C - enables use in under-hood automotive and industrial ambient conditions |
| Dynamic Impedance | 0.2 Ω typical - ensures minimal output voltage perturbation under load transients |
| Cathode Current | 1 mA to 100 mA - supports direct drive of optocoupler LEDs in isolated SMPS feedback loops |
| Temp Drift | 14 mV max over full range - guarantees ≤0.56% reference error across operating temperature |
| Output Noise | Low broadband noise - critical for low-noise LDOs and precision ADC references |
| Min Cathode Current | 0.4 mA - defines lowest usable current for stable regulation in ultra-low-power designs |
Pinout & Package
SOT-89 package (3-pin, 4.5 mm × 2.5 mm × 1.6 mm body), thermally enhanced with exposed tab connected to ANODE for PCB heat sinking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| REF | Reference input | High-impedance comparator input; connects to resistor divider midpoint for voltage sensing |
| ANODE | Common return | Ground reference node; internally tied to substrate and exposed thermal pad |
| CATHODE | Current sink output | Active output terminal; sinks regulated current to control external pass device or optocoupler |
Key Features
| Feature | Design Value |
|---|---|
| Initial accuracy | ±0.5% (B grade) - reduces calibration overhead in factory-trimmed power modules |
| Adjustable range | Vref to 36 V - enables single-part support for 3.3 V, 5 V, 12 V, 24 V, and 48 V outputs |
| Thermal stability | 14 mV max drift (−40°C to 125°C) - maintains tight output regulation without external compensation |
| Low Iref | 2–4 µA input current - minimizes divider network power loss and improves light-load efficiency |
| Fast turn-on | Sharp regulation knee - prevents output overshoot during startup and line transients |
Applications
| Rack Server Power | Industrial AC/DC Converter |
|---|---|
Use Scenario: Secondary-side voltage regulation in 1U server PSUs with digital PMBus control. IC Role / Device Role / Timing Role: Shunt reference in optocoupler-coupled feedback loop, setting 12 V output with ±1% tolerance. Use Value: Enables compliance with 80 PLUS Titanium efficiency requirements via precise, low-drift feedback. |
Use Scenario: Output voltage stabilization in DIN-rail mounted 24 V/48 V industrial power supplies. IC Role / Device Role / Timing Role: Adjustable reference controlling TL431-based TL431-controlled linear post-regulator stage. Use Value: Maintains <±0.5% output accuracy across −25°C to +70°C cabinet temperatures without recalibration. |
| AC Inverter Drive | Servo Drive Control Module |
Use Scenario: DC bus voltage monitoring and overvoltage protection in 3-phase VFDs. IC Role / Device Role / Timing Role: Precision threshold detector feeding comparator input for fast shutdown logic. Use Value: Delivers 14 mV max drift over −40°C to 125°C, ensuring reliable trip point across motor enclosure environments. |
Use Scenario: Isolated feedback for dual-output servo supply (±15 V analog + 5 V logic). IC Role / Device Role / Timing Role: Dual TL431IPKG3 units regulating independent windings on auxiliary transformer. Use Value: SOT-89 thermal performance (52°C/W) sustains 100 mA sink current without derating in compact drive enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431CDBZR | SOT-23-3, C-temp (0°C to 70°C), ±2% initial tolerance | Limited to commercial ambient; lower accuracy requires tighter resistor tolerances | Lower-cost option for non-automotive consumer power adapters |
| TL431BQDBZR | SOT-23-3, Q-temp (−40°C to 125°C), ±0.5% tolerance, same thermal drift spec | Same temp range and accuracy but smaller SOT-23-3 footprint and higher RθJA (206°C/W) | Preferred when board space is constrained and thermal margin allows |
Compared with TL431IPKG3, TL431CDBZR trades temperature range and accuracy for cost and size, while TL431BQDBZR matches key specs in a smaller package with reduced thermal performance-requiring careful layout for >50 mA loads.
Availability
TL431IPKG3 is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC converters, and servo drive control modules requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TL431IPKG3 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 ICs, with decades of expertise in precision reference design.
The TL431 product line delivers programmable shunt references optimized for feedback stability, thermal robustness, and wide-voltage operation in industrial, automotive, and computing power systems.
FAQ
What is the reference voltage tolerance of TL431IPKG3 at 25°C?
The TL431IPKG3 has a reference voltage tolerance of ±0.5% at 25°C, corresponding to the B-grade specification. This yields a nominal 2.495 V output with a guaranteed range of 2.483 V to 2.507 V under standard test conditions (VKA = Vref, IKA = 10 mA). This tight tolerance reduces system-level calibration effort in precision power supplies.
Does TL431IPKG3 support operation beyond 125°C junction temperature?
No, TL431IPKG3 is rated for maximum junction temperature of 150°C, but its specified operating free-air temperature range is −40°C to +125°C (Q-grade). Exceeding 125°C ambient requires thermal design verification using RθJA = 52°C/W and derating calculations per TI's recommended operating conditions to avoid reliability degradation.
Can TL431IPKG3 replace a Zener diode in a linear regulator design?
Yes, TL431IPKG3 is explicitly designed as a superior Zener diode replacement. Its active circuitry provides sharper turn-on, lower dynamic impedance (0.2 Ω vs. typical Zener's 5–20 Ω), and adjustable output (2.495 V to 36 V) using two external resistors-enabling higher accuracy and better load regulation than passive Zeners.
What is the minimum cathode current required for regulation in TL431IPKG3?
The TL431IPKG3 requires a minimum cathode current of 0.4 mA to maintain regulation, as specified in the electrical characteristics table. Below this threshold, the device exits regulation and output voltage collapses. This value is consistent across all grades and temperature ranges, enabling predictable low-power design margins.
How does the SOT-89 package of TL431IPKG3 improve thermal performance versus SOT-23 variants?
The SOT-89 package of TL431IPKG3 features an exposed thermal pad tied to the ANODE pin, achieving RθJA = 52°C/W-significantly lower than SOT-23-3's 206°C/W. This allows sustained 100 mA cathode current dissipation with minimal temperature rise, making it suitable for high-current feedback paths in industrial power modules where thermal headroom is critical.
TL431IPKG3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-243AA
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- 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:
- ±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-89-3
TL431IPKG3 FAQ
1.How can I place an order for TL431IPKG3 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431IPKG3 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 TL431IPKG3 reliable?
The price and inventory of TL431IPKG3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431IPKG3 is usually 5 days.
3.What payment methods are accepted for TL431IPKG3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431IPKG3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431IPKG3?
TL431IPKG3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431IPKG3 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 TL431IPKG3?
For technical support, including TL431IPKG3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431IPKG3 requirements.
6.How does Aetrix verify that TL431IPKG3 is sourced from the original manufacturer or authorized distributors?
All TL431IPKG3 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 TL431IPKG3 meets industry standards.
7.What is the process for return or replacement of TL431IPKG3?
All TL431IPKG3 units undergo pre-shipment inspection (PSI). If there is an issue with TL431IPKG3, 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 TL431IPKG3 part is unused and in its original packaging.
Return procedure for TL431IPKG3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431IPKG3 Tags
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TL431AIDBZR
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TL431BQDBZR
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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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