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

STMicroelectronics TS431IYLT

Name: TS431IYLT
Brand: STMicroelectronics
SKU: TS431IYLT
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: TS431IYLT

Manufacturer:: STMicroelectronics

Category:: Voltage Reference

Package:: SC-74A, SOT-753

Datasheet:: TS431IYLT.pdf

Description:: IC VREF SHUNT ADJ 2% SOT23-5

Quantity:: RFQ Add To RFQ list

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Inventory:2,139

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Product details

Overview

TS431IYLT from STMicroelectronics is an AEC-Q100 qualified, adjustable shunt voltage reference IC in SOT23-5 package, delivering 2% initial voltage accuracy over 1.24–6 V output range, 0.2 Ω output impedance, and stable operation down to 60 µA cathode current. It serves as a precision feedback element in automotive-grade 3.3 V switching power supplies, especially when driving optocouplers in isolated flyback regulators.

For engineers reviewing the TS431IYLT datasheet, TS431IYLT pinout, TS431IYLT application, or TS431IYLT equivalent, key selection criteria include its automotive qualification (−40 °C to +125 °C), low-voltage regulation capability (1.24 V min), temperature coefficient (100 ppm/°C), and compatibility with capacitive loads without external compensation.

Technical Context

The TS431IYLT implements a bandgap-based three-terminal shunt reference architecture with internal error amplifier and reference voltage (V_REF = 1.24 V). Its cathode-anode voltage regulation is set externally via two resistors, enabling programmable output from 1.24 V to 6 V while maintaining stability across 60 µA–30 mA cathode current range.

It features low dynamic output impedance (0.2 Ω typ.), minimal input current drift (≤240 nA over −40 °C to +125 °C), and inherent immunity to capacitive loading-eliminating need for series resistance or external compensation in most feedback loops.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage Range	1.24 V to 6 V - Programmable via external resistor divider; enables flexible feedback design for 3.3 V, 5 V, or custom rail regulation.
Initial Accuracy	±2% - Guaranteed at 25 °C; supports tight output tolerance in automotive power supply feedback paths.
Temp. Coefficient	100 ppm/°C - Predictable drift over −40 °C to +125 °C; ensures < ±15 mV total V_REF shift across full automotive temperature range.
Cathode Current Range	60 µA to 30 mA - Enables ultra-low-power standby regulation and robust load transient response in SMPS feedback networks.
Output Impedance	0.2 Ω (typ.) - Minimizes output voltage perturbation under dynamic load steps; critical for stable optocoupler-driven loop control.
ESD Rating	HBM: 2 kV - Meets automotive board-level ESD robustness requirements without additional protection circuitry.

Pinout & Package

SOT23-5 plastic micropackage (ECOPACK® compliant), 1.3 mm × 2.9 mm footprint, 1.3 mm height, thermal resistance R_thJA = 250 °C/W.

Pin/Terminal	Circuit Role	Design Meaning
Cathode (K)	Regulated output node	Connected to SMPS transformer secondary or optocoupler anode; sinks current to maintain precise VKA voltage.
Anode (A)	Reference return path	Typically tied to power supply ground or auxiliary winding return; completes shunt current path.
Ref (R)	Feedback input	High-impedance reference comparator input; senses divided output voltage to adjust cathode current.
NC (Pin 4)	No connect	Internally unconnected; must be left floating or grounded per layout best practice-no functional role.
NC (Pin 5)	No connect	Internally unconnected; no electrical function; avoid routing signals or traces to this terminal.

Key Features

Feature	Design Value
AEC-Q100 qualified	Validated for automotive applications (Grade 1: −40 °C to +125 °C ambient), including stress testing per AEC-Q001/Q002.
Low-voltage start-up	Operates down to 1.24 V cathode-anode voltage-enables regulation in low-dropout or multi-rail systems where TL431 cannot function.
Capacitive-load stability	No external compensation required up to ≥10 µF-simplifies feedback network design in isolated DC-DC converters.
Ultra-low I_min	60 µA minimum cathode current for regulation-reduces quiescent power loss in always-on automotive subsystems.
Low output impedance	0.2 Ω typical-maintains regulation accuracy during fast load transients common in microcontroller power domains.

Applications

Automotive Infotainment Power Supply

Industrial PLC 5 V Auxiliary Rail

Use Scenario: Regulating isolated 5 V auxiliary supply for head unit MCU and display interface in vehicles.

IC Role / Device Role / Timing Role: Shunt reference in optocoupler-coupled feedback loop of flyback converter.

Use Value: AEC-Q100 qualification ensures reliability across thermal cycling; 2% accuracy maintains SoC core voltage within spec under battery voltage sag.

Use Scenario: Providing stable 5 V bias for analog I/O modules in factory automation controllers.

IC Role / Device Role / Timing Role: Precision voltage reference for isolated DC-DC feedback network.

Use Value: 100 ppm/°C TC and 0.2 Ω Z_OUT prevent output drift during ambient temperature swings in uncooled enclosures.

USB-C PD Adapter Feedback

Medical Sensor Signal Chain Reference

Use Scenario: Setting regulated 3.3 V output in compact USB-C power adapter with galvanic isolation.

IC Role / Device Role / Timing Role: Adjustable shunt reference controlling optocoupler LED current in primary-side controller feedback path.

Use Value: 60 µA I_min enables efficient light-load regulation; SOT23-5 footprint saves PCB space vs. TO-92 alternatives.

Use Scenario: Generating precise 2.5 V reference for 16-bit ADC in portable patient monitor front-end.

IC Role / Device Role / Timing Role: Low-noise, low-drift voltage reference for analog signal conditioning stage.

Use Value: 100 ppm/°C TC and <21 mV ΔV_REF over −40 °C to +125 °C ensure measurement repeatability across clinical environments.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TL431ACDBVR	Higher minimum cathode current (1 mA), wider V_KA range (2.5–36 V), no AEC-Q100 qualification.	Not suitable for automotive temperature range or ultra-low-power designs; requires higher bias current.	Select only for non-automotive industrial applications where cost is prioritized over temperature stability and low-I_Q.
AS431ASTZTR-G1	Same 2% accuracy and SOT23-5 package, but rated only to +85 °C ambient; lacks AEC-Q100 validation.	Acceptable for commercial-grade power supplies but fails automotive qualification requirements.	Use only in consumer or industrial equipment with limited thermal envelope; not approved for vehicle deployment.

Compared with TL431ACDBVR and AS431ASTZTR-G1, TS431IYLT uniquely combines AEC-Q100 Grade 1 qualification, 60 µA regulation threshold, and 100 ppm/°C TC-making it the sole choice for automotive SMPS feedback where both reliability and low-power operation are mandatory.

Availability

TS431IYLT is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial PLC power rails, and USB-C PD adapters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TS431IYLT 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 power management applications.

The TS431 belongs to ST's precision analog voltage reference product line, engineered specifically for high-reliability feedback control in automotive and industrial power conversion systems.

FAQ

What is the maximum cathode current rating for TS431IYLT in SOT23-5 package?

The TS431IYLT supports continuous cathode current up to +30 mA and can withstand peak currents to +40 mA per absolute maximum ratings. At 30 mA, power dissipation in the SOT23-5 package reaches 500 mW limit-thermal derating is required above +85 °C ambient to maintain reliability.

Can TS431IYLT replace TL431 in existing designs?

Yes, with minor resistor recalculations: TS431IYLT has identical pinout (K-A-R) and same 1.24 V reference, but lower minimum cathode current (60 µA vs. 1 mA) and tighter temperature coefficient. Layout changes are unnecessary, though feedback divider values may be optimized for improved light-load efficiency.

Is the NC pin on TS431IYLT electrically connected internally?

No-pins 4 and 5 of the SOT23-5 package are confirmed as no-connect terminals per ST's mechanical drawings and electrical characterization. They must remain unconnected in PCB layout; grounding or routing signals to them may cause unintended coupling or reliability issues.

Does TS431IYLT require external compensation for stability?

No-TS431IYLT is characterized as stable with any capacitive load up to at least 10 µF, verified by phase margin >50° in gain-phase measurements. Unlike TL431, it does not require series resistance or RC snubbers in standard optocoupler feedback configurations.

TS431IYLT Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Package/Case:: SC-74A, SOT-753

Series:: -

Packaging:: Tape & Reel (TR)

Product Status:: Active

Reference Type:: Shunt

Output Type:: Adjustable

Voltage - Output (Min/Fixed):: 1.24V

Voltage - Output (Max):: 6 V

Current - Output:: 30 mA

Tolerance:: ±2%

Temperature Coefficient:: 100ppm/°C

Noise - 0.1Hz to 10Hz:: -

Noise - 10Hz to 10kHz:: -

Voltage - Input:: -

Current - Supply:: -

Current - Cathode:: 60 µA

Operating Temperature:: -40°C ~ 125°C (TA)

Grade:: Automotive

Qualification:: AEC-Q100

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-5

TS431IYLT FAQ

1.How can I place an order for TS431IYLT through Aetrix?

Please submit a Request for Quotation (RFQ) for TS431IYLT 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 TS431IYLT reliable?

The price and inventory of TS431IYLT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TS431IYLT is usually 5 days.

3.What payment methods are accepted for TS431IYLT?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TS431IYLT transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for TS431IYLT?

TS431IYLT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your TS431IYLT 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 TS431IYLT?

For technical support, including TS431IYLT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TS431IYLT requirements.

6.How does Aetrix verify that TS431IYLT is sourced from the original manufacturer or authorized distributors?

All TS431IYLT 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 TS431IYLT meets industry standards.

7.What is the process for return or replacement of TS431IYLT?

All TS431IYLT units undergo pre-shipment inspection (PSI). If there is an issue with TS431IYLT, 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 TS431IYLT part is unused and in its original packaging.

Return procedure for TS431IYLT:

1.Submit a request within 90 days.

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

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