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

STMicroelectronics TS3431ILT

Name: TS3431ILT
Brand: STMicroelectronics
SKU: TS3431ILT
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: TS3431ILT

Manufacturer:: STMicroelectronics

Category:: Voltage Reference

Package:: TO-236-3, SC-59, SOT-23-3

Datasheet:: TS3431ILT.pdf

Description:: IC VREF SHUNT ADJ 2% SOT23-3

Quantity:: RFQ Add To RFQ list

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Inventory:5,262

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Product details

Overview

TS3431ILT from STMicroelectronics is an adjustable precision shunt voltage reference IC in SOT23-3L package, designed for feedback regulation in switching power supplies and battery management circuits. It delivers 1.24 V to 24 V output with ±0.25% initial accuracy (TS3431C grade), 100 ppm/°C temperature coefficient, -40 °C to +105 °C operating range, and 0.4–100 mA sink current capability.

For engineers reviewing the TS3431ILT datasheet, TS3431ILT pinout, TS3431ILT application, or TS3431ILT equivalent, this page provides verified electrical specifications, thermal stability data, cathode-anode voltage dependency (ΔVREF/ΔVKA = 1.2–2 mV/V), noise performance (100 nV/√Hz), and real-world use cases in SMPS feedback loops, battery charger references, and portable instrumentation.

Technical Context

The TS3431ILT operates as a two-terminal programmable shunt regulator: its reference input (pin 2) senses voltage across an external resistor divider, triggering cathode-to-anode conduction when threshold is exceeded. Its internal bandgap core ensures stable 1.24 V reference with <21 mV drift over -40 °C to +125 °C.

It exhibits low dynamic impedance (0.2–0.4 Ω), wideband noise of 100 nV/√Hz (1–100 kHz), and off-state leakage as low as 35 nA at 25 °C - enabling high-accuracy closed-loop control in space-constrained DC-DC converters and battery protection ICs.

Key Specifications

Parameter	Value and Actual Design Meaning
Reference Voltage	1.24 V nominal, adjustable to 24 V via external resistors - enables flexible feedback design without discrete Zener networks.
Initial Accuracy	±0.25% (TS3431C grade) at 25 °C - supports tight output regulation in telecom and industrial SMPS.
Temp. Coefficient	100 ppm/°C (-40 to +125 °C) - ensures ≤0.21% total drift over full industrial range, critical for battery voltage monitoring.
Sink Current Range	0.4–100 mA - accommodates both low-power sensor references and high-current optocoupler drivers in isolated PSUs.
Dynamic Impedance	0.2–0.4 Ω - minimizes loop gain variation in error amplifier feedback paths, improving transient response stability.
Wideband Noise	100 nV/√Hz (1–100 kHz) - reduces output ripple contribution in precision analog sensing and ADC reference buffers.
Off-State Leakage	35–500 nA at 25 °C (VK = 24 V) - preserves battery runtime in always-on charging circuits and low-power IoT devices.

Pinout & Package

SOT23-3L plastic micropackage (3-pin surface-mount), 2.9 mm × 1.3 mm footprint, 1.12 mm height, JEDEC TO-236AB compliant. Thermal resistance R_thJA = 340 °C/W enables 360 mW dissipation at T_amb = 25 °C.

Pin/Terminal	Circuit Role	Design Meaning
1 (Anode)	Anode terminal	Connected to system ground or low-side return path; defines cathode-to-anode voltage (V_KA) reference plane.
2 (Reference)	Reference input	High-impedance sense node (I_REF = 1.5–2.5 µA); sets regulation point via external resistor divider to cathode.
3 (Cathode)	Cathode terminal	Current-sinking output node; drives optocoupler LED or error amplifier input; voltage range: 1.24–24 V.

Key Features

Feature	Design Value
Adjustable Output	1.24–24 V via two-resistor divider - eliminates need for multiple fixed-voltage references in multi-rail systems.
Precision Grades	±2%, ±1%, ±0.5%, ±0.25% options - allows cost-performance trade-off selection per application tolerance requirements.
Low Input Current	I_REF = 1.5–2.5 µA at 25 °C - minimizes divider power loss and improves battery life in portable equipment.
Industrial Temp Range	-40 °C to +105 °C operation - qualified for under-hood automotive modules and industrial motor drives.
ESD Robustness	2 kV HBM - withstands handling and board assembly stresses without parameter shift or failure.

Applications

SMPS Feedback Loop

Battery Charger Reference

Use Scenario: Primary-side feedback in isolated flyback converters using optocoupler-coupled error signal.

IC Role / Device Role / Timing Role: Shunt reference providing precise voltage threshold to drive optocoupler LED current.

Use Value: Enables ±1% output regulation across line/load/temperature with minimal external components and no secondary-side controller.

Use Scenario: Voltage reference for Li-ion battery charge termination circuitry in portable power banks.

IC Role / Device Role / Timing Role: Precision 4.2 V reference (via resistor divider) for comparator-based end-of-charge detection.

Use Value: Prevents overcharging by maintaining ±0.25% reference accuracy over -20 °C to +60 °C ambient, extending cell cycle life.

Portable Instrumentation

Industrial Sensor Signal Conditioning

Use Scenario: Reference source for 12-bit SAR ADC in handheld multimeter front-end.

IC Role / Device Role / Timing Role: Low-noise (100 nV/√Hz), low-drift voltage reference for ADC V_REF input.

Use Value: Limits integral nonlinearity error to <0.5 LSB over temperature, enabling true 12-bit measurement fidelity.

Use Scenario: Excitation reference for 350 Ω strain gauge bridge in factory-floor load cell interface.

IC Role / Device Role / Timing Role: Stable 5 V reference (R-divider configured) driving bridge excitation and instrumentation amplifier gain-setting resistors.

Use Value: Reduces temperature-induced zero drift to <0.05% FS/°C, meeting Class C industrial accuracy standards.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TL431ACDT	Fixed 2.5 V reference; ±1% initial accuracy; higher I_REF (4 µA typ); 0.5 Ω dynamic impedance	Limited to 2.5 V applications; less flexible for custom output voltages	Select when fixed 2.5 V reference suffices and lower cost is prioritized over adjustability.
MAX6008AEUR+T	Fixed 1.25 V output; ±0.2% accuracy; 35 ppm/°C TC; 1.5 µA I_REF; SOT23-3	No external resistor adjustment; optimized for ultra-low-power sensor biasing	Choose for battery-powered sensors requiring sub-µA quiescent current and tighter TC than TS3431ILT.

Compared with TL431ACDT and MAX6008AEUR+T, the TS3431ILT uniquely balances wide output adjustability (1.24–24 V), ±0.25% accuracy, and industrial temperature support - making it optimal for multi-output SMPS and battery management where flexibility and precision coexist.

Availability

TS3431ILT is available at Aetrix Electronics and suitable for switch-mode power supply feedback, battery charger reference, and portable instrumentation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TS3431ILT 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 microcontrollers, power ICs, sensors, and analog components for industrial, automotive, and consumer markets.

The TS3431 series belongs to ST's precision analog portfolio, engineered specifically for high-stability voltage reference applications in space-constrained, thermally demanding environments such as DC-DC converters and battery management systems.

FAQ

What is the minimum cathode operating current for stable regulation?

The TS3431ILT requires ≥0.5 mA cathode current across its full operating temperature range (-40 °C to +105 °C) to maintain regulation. At 25 °C, minimum current drops to 0.4 mA. Below this threshold, reference voltage may deviate beyond specified accuracy limits due to insufficient internal bias current.

How does cathode-to-anode voltage affect reference accuracy?

Voltage changes across the cathode-anode terminals induce ΔVREF/ΔVKA of 1.2–2 mV/V depending on temperature. At 25 °C and IK = 10 mA, this is 1.2–1.5 mV/V; worst-case is 2 mV/V over -40 °C to +125 °C. This sensitivity must be accounted for in high-VKA designs (>12 V).

Can TS3431ILT replace TL431 in existing designs?

Yes - TS3431ILT is pin-compatible with TL431 in SOT23-3L and shares identical anode-reference-cathode pinout. However, its 1.24 V base reference differs from TL431's 2.495 V, requiring resistor divider recalculations to achieve the same output voltage.

What is the maximum power dissipation in SOT23-3L package?

At ambient temperature of 25 °C, the TS3431ILT's SOT23-3L package supports 360 mW power dissipation, calculated using T_j = 150 °C, R_thJA = 340 °C/W. Derating is required above 25 °C ambient - e.g., ~240 mW at 50 °C ambient.

TS3431ILT Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Package/Case:: TO-236-3, SC-59, SOT-23-3

Series:: -

Packaging:: Tape & Reel (TR)

Product Status:: Active

Reference Type:: Shunt

Output Type:: Adjustable

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

Voltage - Output (Max):: 24 V

Current - Output:: 100 mA

Tolerance:: ±2%

Temperature Coefficient:: 100ppm/°C

Noise - 0.1Hz to 10Hz:: -

Noise - 10Hz to 10kHz:: -

Voltage - Input:: -

Current - Supply:: -

Current - Cathode:: 500 µA

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3

TS3431ILT FAQ

1.How can I place an order for TS3431ILT through Aetrix?

Please submit a Request for Quotation (RFQ) for TS3431ILT 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 TS3431ILT reliable?

The price and inventory of TS3431ILT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TS3431ILT is usually 5 days.

3.What payment methods are accepted for TS3431ILT?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TS3431ILT transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for TS3431ILT?

TS3431ILT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your TS3431ILT 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 TS3431ILT?

For technical support, including TS3431ILT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TS3431ILT requirements.

6.How does Aetrix verify that TS3431ILT is sourced from the original manufacturer or authorized distributors?

All TS3431ILT 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 TS3431ILT meets industry standards.

7.What is the process for return or replacement of TS3431ILT?

All TS3431ILT units undergo pre-shipment inspection (PSI). If there is an issue with TS3431ILT, 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 TS3431ILT part is unused and in its original packaging.

Return procedure for TS3431ILT:

1.Submit a request within 90 days.

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

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