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Texas Instruments TL431ILP
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- Part No.:
- TL431ILP
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA)
- Datasheet:
-
TL431ILP.pdf
- Description:
- IC VREF SHUNT ADJ 2.2% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:3,107
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Product details
Overview
TL431ILP from Texas Instruments is a precision programmable shunt voltage reference IC with 1% initial tolerance at 25°C, adjustable output voltage 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 TL431ILP datasheet, TL431ILP pinout, TL431ILP application, or TL431ILP equivalent, this page provides verified electrical specifications, thermal performance data, package-specific pin functions, real-world use cases in AC/DC and servo drive systems, and two validated alternative parts for design flexibility.
Technical Context
The TL431ILP 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 closed-loop regulation circuits where precise voltage thresholding and stable current sinking are required.
It operates as a voltage-controlled current sink: the REF pin senses voltage relative to ANODE, and the CATHODE draws current proportional to the error between sensed voltage and internal reference. This enables programmable regulation without external op-amps while maintaining stability under varying load and temperature conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V ±1% at 25°C - sets precise regulation threshold for feedback networks |
| Output Voltage Range | 2.495 V to 36 V - programmable via two external resistors for flexible system-level voltage scaling |
| Operating Temperature | −40°C to +85°C - qualified for industrial-grade power supply environments |
| Dynamic Impedance | 0.2 Ω typical - ensures minimal output voltage shift under load transients |
| Sink Current Range | 1 mA to 100 mA - supports direct interface with optocouplers and PWM controllers |
| Temperature Drift | ≤14 mV over full range - guarantees <±0.05% output variation across operating temperature |
| Output Noise | Low broadband noise - critical for stable feedback in high-PSRR isolated converters |
Pinout & Package
TL431ILP is supplied in the PDIP-8 (Plastic Dual-In-Line Package, 9.50 mm × 6.35 mm) with lead spacing of 2.54 mm. The package is through-hole mountable and RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3, 4 | ANODE | Common reference node; typically connected to system ground or return path in shunt configuration |
| 5 | REF | Inverting input of internal error amplifier; senses voltage divider output to regulate cathode current |
| 6, 7, 8 | CATHODE | Current-sinking output terminal; connects to primary-side controller or optocoupler LED anode |
Key Features
| Feature | Design Value |
|---|---|
| Programmable Reference | Adjustable 2.495–36 V output using only two external resistors - eliminates need for multiple fixed references |
| High Initial Accuracy | ±1% tolerance (A grade) at 25°C - reduces calibration overhead in factory-set power supplies |
| Low Dynamic Impedance | 0.2 Ω typical - maintains tight regulation during rapid load changes in SMPS feedback loops |
| Wide Sink-Current Range | 1–100 mA operation - directly drives optocoupler LEDs without buffer stages in isolated topologies |
| Industrial Temp Range | −40°C to +85°C operation - supports deployment in motor drives, PLCs, and industrial AC/DC modules |
Applications
| Rack Server Power | Industrial AC/DC |
|---|---|
Use Scenario: Secondary-side voltage sensing and feedback in 48 V input, 12 V/50 A isolated DC-DC modules. IC Role / Device Role / Timing Role: Shunt reference providing precise 2.5 V threshold to optocoupler-driven PWM controller. Use Value: Enables ±1% output regulation across line/load/temperature, meeting server PSU efficiency and accuracy standards. |
Use Scenario: Output voltage regulation in 3 kW industrial rectifier with PFC front-end and LLC resonant stage. IC Role / Device Role / Timing Role: Programmable reference in secondary-side feedback loop, interfacing with TL431-compatible controller. Use Value: Delivers stable 24 V output despite wide input fluctuations and ambient temperature swings up to 85°C. |
| AC Inverter & VF Drives | Servo Drive Control Module |
Use Scenario: DC bus voltage monitoring and overvoltage protection trigger in 7.5 kW variable-frequency drive. IC Role / Device Role / Timing Role: Precision shunt reference feeding comparator input for fast fault detection. Use Value: 14 mV max drift over −40°C to +85°C ensures consistent trip point across environmental conditions. |
Use Scenario: Feedback reference for analog current loop regulation in 3-phase servo amplifier with ±10 V analog command interface. IC Role / Device Role / Timing Role: Stable 2.495 V reference source for DAC output scaling and current sense amplifier offset correction. Use Value: Low 0.2 Ω dynamic impedance prevents gain error in closed-loop current control under dynamic torque loads. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACD | SOIC-8 package; same 1% tolerance and −40°C to +85°C rating; lower RθJA (97°C/W vs. 140°C/W) | Better thermal performance in surface-mount, space-constrained designs; not pin-compatible with PDIP-8 | Select TL431ACD for SMT-based industrial power supplies requiring improved thermal dissipation. |
| TL431BIDR | SOT-23-3 package; 0.5% initial tolerance; same temperature range; higher cost; smaller footprint | Used where ultra-high accuracy and board space savings outweigh through-hole assembly preference | Choose TL431BIDR when ±0.5% reference stability is mandatory and PCB layout permits SMT placement. |
Compared with TL431ILP, TL431ACD offers superior thermal resistance in SOIC packaging for compact SMT layouts, while TL431BIDR delivers tighter 0.5% tolerance in SOT-23-3 for high-accuracy feedback-neither is pin-compatible, but both serve identical functional roles in shunt-regulated feedback paths.
Availability
TL431ILP is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, and servo drive control modules requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for TL431ILP 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 product line was designed specifically for high-accuracy, low-drift shunt regulation in isolated power supplies, industrial controls, and voltage-monitoring safety circuits-emphasizing robustness, programmability, and wide-temperature reliability.
FAQ
What is the reference voltage accuracy of TL431ILP at 25°C?
The TL431ILP has a reference voltage accuracy of ±1% at 25°C, corresponding to a nominal 2.495 V output with a tolerance band of 2.470 V to 2.520 V. This A-grade specification is confirmed in Section 6.8 of the TI SLVS543S datasheet and applies specifically to the ILP variant. TL431ILP maintains this accuracy under recommended operating conditions with 10 mA cathode current and VKA = Vref.
Does TL431ILP support operation beyond 85°C ambient temperature?
No, TL431ILP is rated for operation from −40°C to +85°C ambient (free-air) temperature, as defined by its "I" temperature grade designation. It is not qualified for the extended −40°C to +125°C range (Q grade) or commercial 0°C to +70°C (C grade). Exceeding +85°C ambient may cause parametric shift or reliability degradation per TI's recommended operating conditions in Section 6.4.
What is the minimum cathode current required for regulation in TL431ILP?
The TL431ILP requires a minimum cathode current of 0.4 mA to maintain regulation, as specified in Sections 6.5–6.13 of the datasheet across all temperature grades. This Imin value ensures stable reference behavior when interfacing with high-impedance feedback dividers or low-power optocouplers. Below 0.4 mA, the device exits regulation and Vref becomes undefined.
Can TL431ILP be used in place of a Zener diode in linear regulator designs?
Yes, TL431ILP is explicitly designed as a precision replacement for Zener diodes in shunt regulation applications. Its active circuitry provides sharper turn-on, lower dynamic impedance (0.2 Ω vs. typical Zener's >10 Ω), and programmable voltage (2.495–36 V) - enabling higher accuracy and better transient response in linear post-regulators, voltage monitors, and overvoltage protectors.
What package type does TL431ILP use, and is it RoHS-compliant?
TL431ILP uses the PDIP-8 (Plastic Dual-In-Line Package, 9.50 mm × 6.35 mm) with 2.54 mm lead pitch. Per Texas Instruments' packaging documentation and orderable addendum, the ILP suffix denotes leaded PDIP packaging compliant with RoHS Directive 2011/65/EU. No exemptions apply, and the device is fully lead-free in finish and construction.
TL431ILP Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA)
- Series:
- -
- Packaging:
- Bulk
- 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:
- Through Hole
- Supplier Device Package:
- TO-92-3
TL431ILP FAQ
1.How can I place an order for TL431ILP through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431ILP 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 TL431ILP reliable?
The price and inventory of TL431ILP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431ILP is usually 5 days.
3.What payment methods are accepted for TL431ILP?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431ILP transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431ILP?
TL431ILP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431ILP 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 TL431ILP?
For technical support, including TL431ILP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431ILP requirements.
6.How does Aetrix verify that TL431ILP is sourced from the original manufacturer or authorized distributors?
All TL431ILP 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 TL431ILP meets industry standards.
7.What is the process for return or replacement of TL431ILP?
All TL431ILP units undergo pre-shipment inspection (PSI). If there is an issue with TL431ILP, 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 TL431ILP part is unused and in its original packaging.
Return procedure for TL431ILP:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431ILP Tags
-
TL431AIDBZR
Texas Instruments
-
TL431BQDBZR
Texas Instruments
-
AN431AN-ATRG1
Diodes Incorporated
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LM4040CYM3-2.5-TR
Microchip Technology
-
LM4040CYM3-4.1-TR
Microchip Technology
-
LM4040EIM3-2.5/NOPB
Texas Instruments
-
AZ431LBNTR-G1
Diodes Incorporated
-
LM4040D20IDBZR
Texas Instruments
-
LM4041DIM3-ADJ/NOPB
Texas Instruments
-
LM4040DIM3X-2.5/NOPB
Texas Instruments
-
LM4040DIM3-2.5/NOPB
Texas Instruments
-
AZ431LANTR-G1
Diodes Incorporated
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