Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

STMicroelectronics TL431AIYDT

Name: TL431AIYDT
Brand: STMicroelectronics
SKU: TL431AIYDT
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: TL431AIYDT

Manufacturer:: STMicroelectronics

Category:: Voltage Reference

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

Datasheet:: TL431AIYDT.pdf

Description:: IC VREF SHUNT ADJ 1% 8SO

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:8,284

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

TL431AIYDT from STMicroelectronics is an AEC-Q100 qualified automotive-grade adjustable shunt voltage reference with 1% initial voltage accuracy, −40 °C to +125 °C operating range, 2.5–36 V programmable output, 1–100 mA sink current capability, and 0.22 Ω typical dynamic impedance. It serves as a precision voltage sensing and regulation element in feedback loops of isolated DC-DC converters, battery management systems, and automotive power supplies.

For engineers reviewing the TL431AIYDT datasheet, TL431AIYDT pinout, TL431AIYDT application, or TL431AIYDT equivalent, key selection considerations include its automotive temperature rating, shunt topology constraints, cathode-anode voltage headroom (≤36 V), minimum regulation current (0.5 mA), and SO-8 batwing package thermal resistance (R_thJA = 85 °C/W).

Technical Context

The TL431AIYDT implements a bandgap-based reference core with internal error amplifier and NPN output stage, configured as a 3-terminal shunt regulator where the REF pin senses external resistor divider voltage, and cathode current adjusts to maintain V_REF = 2.47–2.52 V at the reference input. Its operation requires external resistive programming and a minimum cathode-to-anode voltage of V_REF + 2.5 V for stable regulation.

It delivers 1% initial voltage tolerance over full automotive temperature range, exhibits −2.7 to −1.4 mV/V line regulation sensitivity, supports up to 100 mA sink current, and maintains ≤0.5 Ω maximum dynamic impedance across 1–100 mA load variation and 1 kHz bandwidth - enabling fast transient response in closed-loop feedback circuits.

Key Specifications

Parameter	Value and Actual Design Meaning
Reference Voltage	2.47–2.52 V at 25 °C; sets precise trip point for feedback networks in power supply regulation
Voltage Accuracy	±1% over −40 °C to +125 °C; ensures stable output setpoint across automotive thermal extremes
Sink Current Range	1–100 mA; defines usable load current window for shunt regulation without thermal runaway
Dynamic Impedance	0.22 Ω typical; enables tight output voltage control under varying load conditions
Line Regulation	−2.7 to −1.4 mV/V; quantifies output voltage drift per volt change in cathode-anode voltage
Min. Cathode Current	0.5 mA; minimum current required to sustain regulation mode; impacts light-load stability
Thermal Resistance	R_thJA = 85 °C/W (SO-8); determines junction temperature rise under 100 mA sink at ambient

Pinout & Package

TL431AIYDT is housed in an SO-8 batwing plastic micropackage (ECOPACK® compliant), offering improved thermal dissipation vs. TO-92 and SOT-23 variants. The 8-pin layout includes dedicated anode, cathode, and reference terminals plus five no-connect (NC) pins for mechanical reinforcement and isolation.

Pin/Terminal	Circuit Role	Design Meaning
1, 2, 3, 7, 8	No Connect (NC)	Unused pins; electrically isolated; provide mechanical anchoring and thermal path enhancement
4	Anode (A)	Return path for cathode current; tied to system ground or low-side rail in shunt configuration
5	Reference Input (REF)	High-impedance sense node; connected to resistor divider midpoint to monitor regulated output voltage
6	Cathode (K)	Current-sinking output terminal; connects to feedback optocoupler LED or error amplifier input in isolated PSUs

Key Features

Feature	Design Value
AEC-Q100 qualification	Validated for automotive applications including engine control units and ADAS power rails
Adjustable output range	2.5–36 V via two external resistors; eliminates need for multiple fixed-voltage references
Low dynamic impedance	0.22 Ω typical; minimizes output voltage deviation during load transients in feedback loops
Wide sink current capability	1–100 mA operational range; supports direct drive of optocoupler LEDs without buffer stages
Stable over temperature	±1% accuracy maintained from −40 °C to +125 °C; critical for under-hood electronics reliability

Applications

Automotive Power Supply Feedback

Industrial Isolated DC-DC Converter

Use Scenario: Regulating 12 V/24 V battery-derived outputs in engine control modules with wide ambient temperature swings.

IC Role / Device Role / Timing Role: Shunt voltage reference in secondary-side feedback loop, interfacing with optocoupler to close regulation across isolation barrier.

Use Value: Maintains ±1% output accuracy over −40 °C to +125 °C, eliminating calibration drift in harsh under-hood environments.

Use Scenario: Stabilizing 5 V/3.3 V auxiliary rails in programmable logic controller (PLC) power supplies with galvanic isolation.

IC Role / Device Role / Timing Role: Precision reference for TL431-based feedback network controlling PWM duty cycle via optocoupler-coupled error signal.

Use Value: 0.22 Ω dynamic impedance ensures <10 mV output deviation during 100 mA load steps, improving system immunity to field-induced transients.

Battery Management System Reference

Programmable Overvoltage Protection

Use Scenario: Monitoring cell stack voltage in 12S lithium-ion battery packs for electric vehicle traction inverters.

IC Role / Device Role / Timing Role: Adjustable threshold detector comparing divided pack voltage against 2.5 V reference to trigger fault shutdown.

Use Value: 1% initial accuracy and −7 to +30 mV total deviation over temperature enable ±0.1 V detection tolerance at 48 V nominal.

Use Scenario: Enabling user-configurable overvoltage lockout in lab-grade bench power supplies with digital front-panel setting.

IC Role / Device Role / Timing Role: Programmable comparator reference whose trip point scales linearly with external resistor ratio up to 36 V.

Use Value: 2.5–36 V adjustability allows single BOM part to support 3.3 V to 30 V output ranges without redesigning feedback network.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TL431BIDT	0.5% initial accuracy; same SO-8 package and −40 °C to +125 °C rating	Higher precision required in high-end EV charging controllers where ±0.05 V reference error is unacceptable	Select when tighter initial tolerance justifies cost premium; identical pinout and thermal behavior
TLVH431AQDBVR	2.5 V fixed reference; SOT-23-5 package; 1.24 V internal reference; lower 1.5 V cathode-anode headroom	Space-constrained consumer power adapters needing minimal footprint and lower dropout voltage	Choose only if fixed 2.5 V output suffices and PCB area is critical; not drop-in due to different pin count and topology

Compared with TL431AIYDT, TL431BIDT offers higher precision at identical thermal and packaging specs, while TLVH431AQDBVR trades adjustability and automotive qualification for smaller size and lower headroom - making TL431AIYDT optimal for cost-sensitive, temperature-stable, programmable automotive feedback designs.

Availability

TL431AIYDT is available at Aetrix Electronics and suitable for automotive power supply feedback, industrial isolated DC-DC converters, and battery management system reference applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TL431AIYDT 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 analog, microcontroller, power, and sensor solutions for automotive, industrial, and consumer markets.

The TL431 product line delivers precision programmable shunt references optimized for closed-loop voltage regulation in safety-critical automotive and industrial power systems - emphasizing thermal robustness, long-term stability, and AEC-Q100 compliance.

FAQ

What is the minimum cathode-to-anode voltage required for TL431AIYDT regulation?

The TL431AIYDT requires a minimum cathode-to-anode voltage (V_KA) of V_REF + 2.5 V to enter and maintain regulation mode. With V_REF = 2.47–2.52 V, this translates to ≥5.0 V absolute minimum. Below this threshold, the device operates in cutoff and cannot regulate output voltage.

Can TL431AIYDT replace TL431CD in existing designs?

No - TL431AIYDT is automotive-grade (−40 °C to +125 °C, AEC-Q100 qualified) with 1% accuracy, while TL431CD is commercial-grade (0 °C to +70 °C) with 2% accuracy and SO-8 packaging. Substitution requires validation of thermal margin, long-term stability, and qualification documentation for automotive use cases.

How does the SO-8 batwing package improve thermal performance over TO-92?

The SO-8 batwing package reduces junction-to-ambient thermal resistance to 85 °C/W versus 200 °C/W for TO-92, enabling 2.3× higher continuous power dissipation at the same ambient temperature. This allows reliable 100 mA sink operation without external heatsinking in compact automotive modules.

Is external compensation required when driving capacitive loads?

Yes - the TL431AIYDT exhibits conditional stability with capacitive loads >100 nF. Figure 21 in the datasheet shows oscillation risk above this threshold; a series resistor (typically 10–100 Ω) between cathode and capacitive node is required to maintain phase margin >45° and prevent sustained ringing in feedback paths.

TL431AIYDT Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

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

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 ~ 125°C (TA)

Grade:: Automotive

Qualification:: AEC-Q100

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SOIC

TL431AIYDT FAQ

1.How can I place an order for TL431AIYDT through Aetrix?

Please submit a Request for Quotation (RFQ) for TL431AIYDT 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 TL431AIYDT reliable?

The price and inventory of TL431AIYDT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431AIYDT is usually 5 days.

3.What payment methods are accepted for TL431AIYDT?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431AIYDT transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for TL431AIYDT?

TL431AIYDT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your TL431AIYDT 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 TL431AIYDT?

For technical support, including TL431AIYDT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431AIYDT requirements.

6.How does Aetrix verify that TL431AIYDT is sourced from the original manufacturer or authorized distributors?

All TL431AIYDT 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 TL431AIYDT meets industry standards.

7.What is the process for return or replacement of TL431AIYDT?

All TL431AIYDT units undergo pre-shipment inspection (PSI). If there is an issue with TL431AIYDT, 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 TL431AIYDT part is unused and in its original packaging.

Return procedure for TL431AIYDT:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-10 Schmitt Trigger Explained: Hysteresis, Circuits, Inverters and Applications

Schmitt triggers use separate rising and falling thresholds to stabilize slow or noisy signals. This guide covers hysteresis, 74HC14 and 74HCT14 selection, comparator calculations, RC oscillators and p…

2026-09-09 Counterfeit Electronic Components: How to Detect, Authenticate, and Test Suspect Parts

Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…