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Texas Instruments TL431AILPR
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- Part No.:
- TL431AILPR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
TL431AILPR.pdf
- Description:
- IC VREF SHUNT ADJ 1% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:6,938
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Product details
Overview
TL431AILPR 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 TL431AILPR datasheet, TL431AILPR pinout, TL431AILPR application, or TL431AILPR equivalent, key selection considerations include its A-grade accuracy, I-temp range suitability for industrial power control, low temperature drift (14 mV over −40°C to 85°C), and compatibility with standard resistor-divider programming for stable voltage regulation.
Technical Context
The TL431AILPR implements a three-terminal adjustable shunt regulator architecture with an internal 2.495 V reference, error amplifier, and NPN output stage. Its sharp turn-on characteristic and active output circuitry enable Zener diode replacement in closed-loop regulation without external compensation in many configurations.
It operates as a two-input comparator driving a cathode-sink output: the REF pin senses voltage relative to ANODE, while cathode current (IKA) adjusts to maintain VREF across external resistors. Thermal stability is ensured via on-die trimming, with specified VI(dev) = 14 mV max over full I-temp range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.470–2.520 V at 25°C (A-grade, ±1% tolerance); sets precise regulation threshold for feedback networks |
| Temp Range | −40°C to +85°C (I-grade); validated for industrial ambient conditions without derating |
| Dynamic Impedance | 0.2 Ω typical (≤0.5 Ω max); ensures minimal output voltage shift under load transients |
| Sink Current Range | 1–100 mA; supports direct drive of optocoupler LEDs or error amplifier inputs in isolated PSUs |
| Ref Input Current | 2–4 µA typical; enables high-impedance resistor-divider design (e.g., 10 kΩ–1 MΩ) with <0.1% error contribution |
| Temp Drift (VI(dev)) | 14 mV max over −40°C to 85°C; translates to ~100 ppm/°C average coefficient for stable setpoint accuracy |
| Off-State Leakage | ≤0.5 µA at 36 V cathode voltage; prevents unintended conduction in shutdown or standby modes |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm body size), surface-mount, RoHS-compliant. Pin 1: Cathode (output sink node); Pin 2: Anode (common return/reference ground); Pin 3: Ref (precision input sensing node).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Pin 1) | Current-sink output terminal | Connects to PSU output via optocoupler LED or directly to regulated rail; sinks current to adjust feedback voltage |
| Anode (Pin 2) | Common reference and return path | Typically tied to system ground or PSU return; serves as voltage reference point for REF pin measurement |
| Ref (Pin 3) | Precision voltage sense input | Monitors divided output voltage; triggers regulation when input equals internal 2.495 V reference |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable Output Range | 2.495 V to 36 V via two-resistor divider - enables single BOM part for multiple output voltages |
| Low Dynamic Impedance | 0.2 Ω typical - maintains tight regulation during fast load steps without external capacitor stabilization |
| I-Temp Grade Operation | −40°C to +85°C - qualified for industrial power systems where commercial-grade parts fail |
| A-Grade Initial Accuracy | ±1% at 25°C - reduces calibration overhead in factory programming and improves open-loop PSU accuracy |
| Low Reference Input Current | 2–4 µA - allows use of high-value resistors (>100 kΩ) to minimize divider power loss and thermal drift |
Applications
| AC/DC Power Supply Feedback | Rack Server VRM Monitoring |
|---|---|
Use Scenario: Secondary-side voltage sensing in offline flyback or forward converters with optocoupler isolation. IC Role / Device Role / Timing Role: Precision shunt reference providing error signal to optocoupler LED, closing regulation loop across isolation barrier. Use Value: Enables ±1% output voltage accuracy over line/load/temperature, meeting 80 PLUS Titanium requirements. |
Use Scenario: Remote sensing and margining of 12 V, 5 V, and 3.3 V rails in multi-phase server VRMs. IC Role / Device Role / Timing Role: Programmable reference for DAC-controlled voltage margining circuits and fault detection comparators. Use Value: A-grade tolerance and low temp drift ensure reliable margining thresholds across chassis temperature gradients. |
| Industrial Motor Drive PSU | Programmable Lab Power Supply |
Use Scenario: Output voltage regulation in auxiliary 24 V DC/DC supplies powering gate drivers and MCU in servo inverters. IC Role / Device Role / Timing Role: Shunt reference in linear post-regulator stage, stabilizing supply for sensitive analog interfaces. Use Value: 0.2 Ω impedance minimizes dropout and ripple under dynamic motor load transients. |
Use Scenario: Core reference element in digitally controlled bench supplies with variable output (0–30 V). IC Role / Device Role / Timing Role: Adjustable reference setting DAC reference voltage or op-amp setpoint in closed-loop control. Use Value: 1% accuracy and 14 mV temp drift support ≤0.5% total output uncertainty over operating range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431AIDBZR | SOT-23-3, same A-grade accuracy and I-temp range, but tape-and-reel packaging differs (DBZR vs LPR) | Identical electrical performance; DBZR optimized for high-volume automated assembly, LPR for lower-quantity prototyping | Select TL431AILPR for standard reel packaging with verified traceability; choose TL431AIDBZR only if machine vision alignment or specific carrier tape specs are required |
| TLVH431AILP | Lower 1.24 V reference, 1% accuracy, same SOT-23-3 package, but higher 6 µA ref current and 0.35 Ω impedance | Better suited for low-voltage rails (<5 V); less stable at high cathode voltages due to reduced headroom and higher impedance | Use TL431AILPR for outputs ≥5 V or where <0.5 Ω impedance is critical; reserve TLVH431AILP for sub-3.3 V applications with tighter space constraints |
Compared with TL431AIDBZR, TL431AILPR offers identical regulation performance but distinct packaging logistics; versus TLVH431AILP, it provides superior high-voltage stability and lower output impedance-critical for >12 V industrial supplies.
Availability
TL431AILPR is available at Aetrix Electronics and suitable for AC/DC power supplies, industrial motor drives, and rack server power management requiring stable component supply with guaranteed long-term sourcing.
Supply support for TL431AILPR 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 reference design and power management ICs.
The TL431 family was engineered as a drop-in Zener replacement for high-stability shunt regulation in power conversion, feedback control, and voltage monitoring across industrial, computing, and telecom infrastructure.
FAQ
What is the reference voltage tolerance of TL431AILPR at 25°C?
The TL431AILPR has a reference voltage tolerance of ±1% at 25°C, corresponding to a 2.470 V to 2.520 V range. This A-grade specification is confirmed in Section 6.8 of the TI datasheet (SLVS543S) and applies specifically to the TL431AI variant in SOT-23-3 packaging. The tolerance remains stable across its rated temperature range.
Does TL431AILPR support operation down to −40°C?
Yes, TL431AILPR is rated for operation from −40°C to +85°C (I-grade). Its electrical characteristics-including reference voltage deviation (VI(dev) ≤14 mV), reference current drift, and dynamic impedance-are fully specified across this range per Sections 6.6 and 6.9 of the official TI datasheet.
What is the maximum cathode voltage rating for TL431AILPR?
The absolute maximum cathode voltage (VKA) for TL431AILPR is 37 V, with recommended operating range up to 36 V. This limit is defined in Section 6.1 (Absolute Maximum Ratings) and applies regardless of anode voltage, as all voltages are referenced to the ANODE pin.
Can TL431AILPR replace a Zener diode in feedback circuits?
Yes, TL431AILPR is explicitly designed as a precision Zener diode replacement. Its active error amplifier, sharp turn-on, and 0.2 Ω dynamic impedance provide superior regulation accuracy, temperature stability, and load transient response compared to passive Zeners-especially in optocoupler-based isolated feedback loops.
What is the typical dynamic impedance of TL431AILPR and why does it matter?
TL431AILPR has a typical dynamic impedance of 0.2 Ω (≤0.5 Ω max), measured at 1 kHz with 1–100 mA cathode current. This low value ensures minimal output voltage variation during rapid load changes-critical for maintaining tight regulation in switching power supplies without additional output capacitance.
TL431AILPR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- 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:
- ±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
TL431AILPR FAQ
1.How can I place an order for TL431AILPR through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431AILPR 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 TL431AILPR reliable?
The price and inventory of TL431AILPR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431AILPR is usually 5 days.
3.What payment methods are accepted for TL431AILPR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431AILPR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431AILPR?
TL431AILPR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431AILPR 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 TL431AILPR?
For technical support, including TL431AILPR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431AILPR requirements.
6.How does Aetrix verify that TL431AILPR is sourced from the original manufacturer or authorized distributors?
All TL431AILPR 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 TL431AILPR meets industry standards.
7.What is the process for return or replacement of TL431AILPR?
All TL431AILPR units undergo pre-shipment inspection (PSI). If there is an issue with TL431AILPR, 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 TL431AILPR part is unused and in its original packaging.
Return procedure for TL431AILPR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431AILPR 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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