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Texas Instruments TL431AILPE3
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- Part No.:
- TL431AILPE3
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA)
- Datasheet:
-
TL431AILPE3.pdf
- Description:
- IC VREF SHUNT ADJ 1% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:1,928
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Product details
Overview
TL431AILPE3 from Texas Instruments is a precision programmable shunt voltage reference IC with 1% initial 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, 1–100 mA sink-current capability, and low output noise-enabling accurate feedback in isolated DC-DC converters and industrial power supplies.
For engineers reviewing the TL431AILPE3 datasheet, TL431AILPE3 pinout, TL431AILPE3 application, or TL431AILPE3 equivalent, this page provides verified electrical specifications, SOT-23-3 package details, thermal performance data, and validated alternative parts for power supply feedback loop design, voltage monitoring, and adjustable regulation circuits.
Technical Context
The TL431AILPE3 implements a three-terminal adjustable shunt regulator architecture with an internal 2.495 V reference and high-gain error amplifier. Its sharp turn-on characteristic and active output stage replace Zener diodes in precision regulation applications without requiring external compensation under standard load conditions.
It operates as a two-input (REF/ANODE) comparator driving a cathode current sink, where the REF pin senses voltage relative to ANODE and adjusts cathode current to maintain VREF = 2.495 V ±1%. The device exhibits stable behavior up to 100 µF capacitive loads when properly biased per TI's stability boundary curves for I-grade SOT-23-3 variants.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V ±1% at 25°C - sets precise feedback threshold for power supply regulation loops |
| Temperature Range | −40°C to +85°C - qualified for industrial ambient environments without derating |
| Dynamic Impedance | 0.2 Ω typical - ensures minimal output voltage shift under varying load currents |
| Sink Current Range | 1 mA to 100 mA - supports direct drive of optocoupler LEDs or series-pass transistor bases |
| Reference Input Current | 2–4 µA - enables high-impedance resistor-divider networks with <1% error contribution |
| Output Noise | Low broadband noise - preserves signal integrity in sensitive feedback paths |
| Thermal Drift | 14 mV max over full temperature range - guarantees ≤0.056%/°C average drift for stable long-term accuracy |
Pinout & Package
TL431AILPE3 is housed in a 3-pin SOT-23-3 (DBZ) package measuring 2.90 mm × 1.30 mm, with gull-wing leads and exposed substrate connected to ANODE.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (REF) | Reference input | Senses voltage divider output; must be biased ≥2.495 V above ANODE to activate regulation |
| Pin 2 (CATHODE) | Current sink output | Drains regulated current to external circuit; connects to optocoupler anode or pass transistor base |
| Pin 3 (ANODE) | Common reference node | Acts as return path and voltage reference point; typically tied to system ground or negative rail |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output voltage | 2.495 V to 36 V via two-resistor divider - eliminates need for multiple fixed-voltage references |
| High initial accuracy | ±1% at 25°C (A grade) - reduces calibration overhead in production power supplies |
| Low dynamic impedance | 0.2 Ω typical - maintains tight output regulation despite rapid load transients |
| Wide operating temperature | −40°C to +85°C - supports deployment in motor drives, industrial PLCs, and telecom rectifiers |
| Low reference input current | 2–4 µA - allows use of high-value resistors (>1 MΩ), minimizing quiescent power loss |
Applications
| Rack Server Power Supply | Industrial AC/DC Converter |
|---|---|
Use Scenario: Secondary-side voltage feedback in isolated 48 V–12 V DC-DC modules with optocoupler isolation. IC Role / Device Role / Timing Role: Precision shunt reference setting feedback threshold for PWM controller error amplifier. Use Value: Enables ±1% output voltage regulation across line/load/temperature without trimming, reducing BOM count and test time. |
Use Scenario: Output voltage sensing and regulation in 3 kW industrial AC-DC front-end supplies. IC Role / Device Role / Timing Role: Adjustable reference generating error signal for UC384x-based current-mode control loop. Use Value: Maintains stable 24 V output under 10–100% load steps and −40°C to 85°C ambient, meeting IEC 61000-3-2 harmonic limits. |
| AC Inverter Drive | Notebook PC Adapter |
Use Scenario: DC bus voltage monitoring and overvoltage protection trigger in 3-phase VFDs. IC Role / Device Role / Timing Role: Shunt reference comparing scaled bus voltage against threshold to enable crowbar or shutdown logic. Use Value: Provides fast, repeatable 400 V OV detection with <10 µs response, preventing IGBT failure during regeneration events. |
Use Scenario: Feedback reference in 65 W GaN-based USB-C PD adapter with primary-side regulation assist. IC Role / Device Role / Timing Role: Secondary-side precision reference correcting primary-side estimation error via optocoupler. Use Value: Achieves ±1.5% total output accuracy across 5–20 V PPS profiles, satisfying USB-IF compliance requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACDCKR | Same A-grade accuracy and SOT-23-3 package, but C-temp (0°C to 70°C) rating | Not suitable for industrial environments requiring −40°C startup or 85°C sustained operation | Select only for commercial-grade applications with controlled ambient |
| TL431BILPR | B-grade (±0.5%) accuracy, same I-temp range and SOT-23-3 package | Higher precision enables tighter regulation in high-end server PSUs or medical power supplies | Choose when ±0.5% initial tolerance is required and cost premium is acceptable |
Compared with TL431AILPE3, TL431ACDCKR sacrifices industrial temperature capability for lower cost, while TL431BILPR improves accuracy by 0.5% at the expense of tighter tolerance-driven binning and slightly higher unit price-both require no PCB changes but differ in qualification scope and precision tier.
Availability
TL431AILPE3 is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC converters, and notebook PC adapter designs requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for TL431AILPE3 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 and embedded processing technologies, with decades of expertise in precision analog ICs and power management solutions.
The TL431 family was designed specifically for high-accuracy, low-drift voltage reference applications in isolated power supplies, battery chargers, and industrial control systems-emphasizing robustness, wide temperature operation, and ease of implementation.
FAQ
What is the reference voltage tolerance of TL431AILPE3 at 25°C?
The TL431AILPE3 has a reference voltage tolerance of ±1% at 25°C, corresponding to a nominal 2.495 V output ranging from 2.470 V to 2.520 V under specified test conditions. This A-grade accuracy is confirmed in Section 6.8 of the TI SLVS543S datasheet and applies strictly to the TL431AILPE3 variant with I-temperature qualification and SOT-23-3 packaging.
What package type does TL431AILPE3 use?
TL431AILPE3 uses the SOT-23-3 (DBZ) package, a 3-pin surface-mount outline measuring 2.90 mm × 1.30 mm with gull-wing leads. Pin 2 is the CATHODE, Pin 1 is REF, and Pin 3 is ANODE-this configuration is explicitly defined in Table 5-1 and Figure 5-5 of the TI datasheet for TL431x DBZ variants.
Can TL431AILPE3 operate in industrial temperature environments?
Yes, TL431AILPE3 is rated for operation from −40°C to +85°C (I-grade), making it suitable for industrial applications such as motor drives, PLC power supplies, and telecom rectifiers. Its maximum deviation over this range is 14 mV, verified in Section 6.6 Electrical Characteristics for TL431I devices.
What is the minimum cathode current required for regulation in TL431AILPE3?
The TL431AILPE3 requires a minimum cathode current of 0.4 mA to maintain regulation, as specified in Section 6.6 (TL431I) and Section 6.9 (TL431AI) of the datasheet. Below this threshold, the device exits regulation and cathode voltage rises toward the cathode supply rail.
How does TL431AILPE3 compare to Zener diodes in power supply designs?
TL431AILPE3 replaces Zener diodes by providing superior initial accuracy (±1% vs typical ±5%), lower dynamic impedance (0.2 Ω vs >10 Ω), and adjustable output via external resistors. Unlike Zeners, it features active regulation with sharp turn-on and stable performance across temperature-making it ideal for feedback loops in switching power supplies where precision and consistency are critical.
TL431AILPE3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA)
- 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:
- ±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:
- Through Hole
- Supplier Device Package:
- TO-92-3
TL431AILPE3 FAQ
1.How can I place an order for TL431AILPE3 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431AILPE3 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 TL431AILPE3 reliable?
The price and inventory of TL431AILPE3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431AILPE3 is usually 5 days.
3.What payment methods are accepted for TL431AILPE3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431AILPE3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431AILPE3?
TL431AILPE3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431AILPE3 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 TL431AILPE3?
For technical support, including TL431AILPE3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431AILPE3 requirements.
6.How does Aetrix verify that TL431AILPE3 is sourced from the original manufacturer or authorized distributors?
All TL431AILPE3 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 TL431AILPE3 meets industry standards.
7.What is the process for return or replacement of TL431AILPE3?
All TL431AILPE3 units undergo pre-shipment inspection (PSI). If there is an issue with TL431AILPE3, 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 TL431AILPE3 part is unused and in its original packaging.
Return procedure for TL431AILPE3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431AILPE3 Tags
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TL431AIDBZR
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TL431BQDBZR
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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
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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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