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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Reference

Texas Instruments TL431AID

Name: TL431AID
Brand: Texas Instruments
SKU: TL431AID
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: TL431AID

Manufacturer:: Texas Instruments

Category:: Voltage Reference

Package:: 8-SOIC (0.154", 3.90mm Width)

Datasheet:: TL431AID.pdf

Description:: IC VREF SHUNT ADJ 1% 8SOIC

Quantity:: RFQ Add To RFQ list

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Inventory:1,082

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Product details

Overview

TL431AID from STMicroelectronics is an AEC-Q100 qualified automotive-grade adjustable shunt voltage reference with 1% initial voltage precision (2.5 V nominal), operating from −40 °C to +105 °C, supporting 1–100 mA sink current and delivering 0.22 Ω typical dynamic impedance - used in feedback loops of isolated DC-DC converters and automotive power supply regulation.

For engineers reviewing the TL431AID datasheet, TL431AID pinout, TL431AID application, or TL431AID equivalent, this page provides verified technical context, SO-8 package details, automotive temperature stability data, and real-world design value for precision voltage setting in safety-critical power systems.

Technical Context

The TL431AID implements a precision 2.5 V bandgap reference with internal error amplifier and NPN output stage, configured as a 3-terminal shunt regulator where cathode-anode voltage is set by external resistor divider on the REF pin. It operates over 2.5–36 V output range with guaranteed regulation down to 0.5 mA minimum cathode current.

Its 1% voltage accuracy (V_REF = 2.47–2.52 V at 25 °C) and ±30 mV total deviation over −40 °C to +105 °C enable stable feedback in automotive SMPS and battery management systems. Dynamic impedance remains ≤0.5 Ω across 1–100 mA load, ensuring low output noise and fast transient response.

Key Specifications

Parameter	Value and Actual Design Meaning
V_REF Accuracy	1% (2.47–2.52 V @ 25 °C): Enables precise output voltage setting without calibration in automotive power supplies.
Temp Range	−40 °C to +105 °C: Qualified for under-hood automotive applications including engine control and ADAS power rails.
Sink Current	1–100 mA: Supports direct drive of optocoupler LEDs or high-side gate drivers in isolated flyback controllers.
Dynamic Impedance	0.22 Ω typical: Minimizes output voltage ripple and improves loop stability in closed-loop feedback designs.
Ref Input Current	1.8–6.5 µA: Low bias current reduces divider power loss and enables high-resistance programming networks.
Min Cathode Current	0.5 mA: Ensures reliable regulation even at light loads, critical for standby-mode efficiency in automotive ECUs.
AEC-Q100 Grade	Qualified per AEC-Q100 Rev H: Validated for automotive reliability including HTOL, TC, and ESD (HBM 2 kV).

Pinout & Package

TL431AID is supplied in SO-8 "batwing" plastic micropackage (ECOPACK® compliant), offering improved thermal performance (R_thJA = 85 °C/W) and mechanical robustness for automotive PCB assembly.

Pin	Circuit Role	Design Meaning
1 (Anode)	Anode terminal	Connected to system ground or low-side return path; sinks current when device regulates.
2 (Cathode)	Cathode terminal	High-side output node; connects to supply rail or optocoupler LED anode in isolated feedback.
3 (REF)	Reference input	High-impedance input sensing voltage divider midpoint; sets regulated output via R1/R2 ratio.
4–8 (NC)	No-connect terminals	Internally unconnected; must remain floating or tied to ground per layout guidelines to avoid noise coupling.

Key Features

Feature	Design Value
Adjustable output voltage	2.5–36 V via two external resistors: Eliminates need for multiple fixed-voltage references in multi-rail systems.
Low dynamic impedance	0.22 Ω typical: Maintains tight output regulation under fast load transients common in automotive microcontroller power domains.
Automotive temperature range	−40 °C to +105 °C: Meets extended ambient requirements for body control modules and infotainment power supplies.
Low reference input current	≤6.5 µA max: Allows use of >1 MΩ resistor dividers, reducing quiescent current in always-on circuits.
AEC-Q100 qualification	Full stress testing per Rev H: Confirms suitability for production automotive electronics without additional qualification effort.

Applications

Automotive Power Supply

Isolated Flyback Converter

Use Scenario: Regulating 5 V and 3.3 V rails in vehicle infotainment head units with wide input voltage variation (9–16 V battery).

IC Role / Device Role / Timing Role: Shunt reference in secondary-side feedback loop, setting output voltage via resistor divider and optocoupler.

Use Value: 1% accuracy and −40 °C to +105 °C operation ensure stable rail generation despite engine cranking dips and under-hood thermal cycling.

Use Scenario: Secondary-side voltage sensing in 12 V → 5 V isolated DC-DC converter for ADAS camera modules.

IC Role / Device Role / Timing Role: Precision reference driving optocoupler LED to close regulation loop across transformer barrier.

Use Value: 0.22 Ω dynamic impedance minimizes output voltage deviation during load steps, maintaining image sensor power integrity.

Industrial PLC I/O Module

Battery Management System

Use Scenario: Providing accurate 2.5 V reference for 16-bit ADCs measuring analog sensor inputs in factory automation controllers.

IC Role / Device Role / Timing Role: Stable voltage reference source for analog front-end signal conditioning circuitry.

Use Value: ±30 mV total V_REF drift over temperature ensures <0.1% measurement error across industrial ambient range.

Use Scenario: Monitoring cell voltage thresholds in 12S lithium-ion battery packs for electric power steering systems.

IC Role / Device Role / Timing Role: Programmable threshold detector enabling overvoltage/undervoltage protection logic.

Use Value: Adjustable 2.5–36 V range supports direct cell-string monitoring without level-shifting, simplifying BMS hardware.

Equivalent & Alternatives

The following parts are listed as comparable options for similar adjustable shunt reference applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
TL431BID	0.5% initial accuracy (2.483–2.507 V), same SO-8 package and temp range	Required where tighter output tolerance is needed for high-precision ADC references or low-dropout LDO feedback	Select TL431BID only if system-level calibration is impractical and ±10 mV V_REF error is unacceptable.
TLVH431AIDBVR	Lower 1.24 V reference, 1% accuracy, SOT-23-3 package, 1–80 mA sink, −40 °C to +125 °C	Used when lower reference voltage or smaller footprint is prioritized over 2.5 V compatibility	Choose TLVH431AIDBVR for space-constrained designs needing sub-2.5 V reference or extended junction temperature margin.

Compared with TL431AID, TL431BID offers higher accuracy at identical thermal and packaging specs, while TLVH431AIDBVR trades reference voltage and package size for broader temperature coverage and reduced board area - selection depends on whether precision, footprint, or voltage range dominates the design constraint.

Availability

TL431AID is available at Aetrix Electronics and suitable for automotive power supplies, isolated DC-DC converters, and industrial PLC I/O modules requiring stable component supply with AEC-Q100 compliance and long-term manufacturing continuity.

Supply support for TL431AID 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing silicon solutions for automotive, industrial, and consumer markets since 1987.

The TL431 product line delivers precision programmable shunt references optimized for feedback stability, thermal robustness, and automotive qualification - targeting power supply regulation in safety-critical electronic control units.

FAQ

What is the maximum cathode-to-anode voltage for TL431AID?

The absolute maximum cathode-to-anode voltage (V_KA) is 37 V. Operation above this risks permanent damage. The device regulates up to 36 V output, so design margin requires keeping V_KA ≤36 V under all conditions including transients and ripple.

Can TL431AID replace TL431CD in existing designs?

Yes, TL431AID is a direct functional replacement for TL431CD in terms of pinout, electrical behavior, and SO-8 package, but adds AEC-Q100 qualification and extended −40 °C to +105 °C operation - no schematic or layout changes are needed for automotive upgrade paths.

How does the REF pin input current affect resistor divider design?

REF pin current ranges from 1.8 to 6.5 µA over temperature; to limit divider error to <0.1%, total divider resistance should be ≤25 kΩ. For low-power applications, higher values (e.g., 200 kΩ) are usable but introduce measurable offset due to I_REF × R₁ drop.

Is thermal derating required for TL431AID in SO-8 package?

Yes - with R_thJA = 85 °C/W, power dissipation must be limited to avoid exceeding 150 °C junction temperature. At 100 mA sink and 10 V cathode-anode drop (1 W), ambient must stay below 65 °C; forced airflow or copper pour reduces effective R_thJA and extends usable range.

TL431AID Specifications

Product attributes: Attribute value

Manufacturer:: Texas Instruments

Package/Case:: 8-SOIC (0.154", 3.90mm Width)

Series:: -

Packaging:: Tube

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:: Surface Mount

Supplier Device Package:: 8-SOIC

TL431AID FAQ

1.How can I place an order for TL431AID through Aetrix?

Please submit a Request for Quotation (RFQ) for TL431AID 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 TL431AID reliable?

The price and inventory of TL431AID are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431AID is usually 5 days.

3.What payment methods are accepted for TL431AID?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431AID transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for TL431AID?

TL431AID orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your TL431AID 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 TL431AID?

For technical support, including TL431AID datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431AID requirements.

6.How does Aetrix verify that TL431AID is sourced from the original manufacturer or authorized distributors?

All TL431AID 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 TL431AID meets industry standards.

7.What is the process for return or replacement of TL431AID?

All TL431AID units undergo pre-shipment inspection (PSI). If there is an issue with TL431AID, 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 TL431AID part is unused and in its original packaging.

Return procedure for TL431AID:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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