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STMicroelectronics TS431AILT
- Part No.:
- TS431AILT
- Manufacturer:
- STMicroelectronics
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
TS431AILT.pdf
- Description:
- IC VREF SHUNT ADJ 1% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:9,304
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Product details
Overview
TS431AILT from STMicroelectronics is an AEC-Q100 qualified, adjustable three-terminal shunt voltage reference IC in SOT23-5 package, delivering 1.24–6 V output with 1% initial precision, 100 ppm/°C temperature coefficient, 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 driving optocouplers.
For engineers reviewing the TS431AILT datasheet, TS431AILT pinout, TS431AILT application, or TS431AILT equivalent, key selection criteria include low-voltage regulation capability (≥1.24 V), cathode current range (60 µA–30 mA), output impedance (0.2 Ω typ.), thermal stability (−40 °C to +125 °C), and automotive qualification status.
Technical Context
The TS431AILT implements a bandgap-based reference core with internal error amplifier and NPN pass transistor, enabling precise two-resistor voltage programming across 1.24–6 V. Its architecture supports direct optocoupler biasing without external amplification, reducing loop latency in isolated flyback feedback paths.
It operates with ultra-low minimum cathode current (60 µA) and maintains <0.4 Ω static impedance over 0.1–15 mA cathode current, ensuring stable regulation under light-load and transient conditions. The device exhibits guaranteed stability with any capacitive load and features ESD protection rated at 2 kV HBM.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage Range | 1.24 V to 6 V - Programmable via two external resistors; enables flexible feedback design for 3.3 V, 5 V, or custom rail regulation. |
| Initial Voltage Precision | ±1% at 25 °C - Ensures tight output tolerance without post-manufacturing trimming in automotive power supply feedback loops. |
| Temperature Coefficient | 100 ppm/°C - Guarantees ≤18 mV drift over −40 °C to +125 °C, critical for engine control unit (ECU) power integrity. |
| Cathode Current Range | 60 µA to 30 mA - Supports ultra-low-power standby modes and full-load regulation in isolated DC-DC converters. |
| Static Output Impedance | 0.2 Ω typical - Minimizes output voltage sag during fast load transients, improving dynamic response in closed-loop systems. |
| ESD Protection | 2 kV HBM - Meets automotive board-level robustness requirements without additional protection circuitry. |
Pinout & Package
SOT23-5 plastic micropackage (ECOPACK® compliant), 1.27 mm pitch, 2.8 × 1.6 × 1.3 mm body, with exposed pad not connected internally.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| K (Pin 1) | Cathode | Main current sink terminal; connects to switched node of flyback transformer secondary or optocoupler anode. |
| A (Pin 2) | Anode | Reference ground return path; ties to system GND or isolated secondary ground in feedback circuits. |
| R (Pin 3) | Reference Input | High-impedance input sensing voltage divider output; sets regulated output via resistor ratio R1/R2. |
| N/C (Pin 4) | No Connect | Internally unconnected; must be left floating or tied to A for mechanical stability-no electrical function. |
| N/C (Pin 5) | No Connect | Internally unconnected; same handling as Pin 4-no routing or termination required. |
Key Features
| Feature | Design Value |
|---|---|
| Automotive qualification | AEC-Q100 Grade 1 certified (−40 °C to +125 °C), enabling use in powertrain and body control modules without derating. |
| Low-voltage start-up | Operates down to 1.24 V cathode-anode differential-supports regulation in low-dropout auxiliary rails where TL431 fails. |
| Capacitive load immunity | Stable with any value of output capacitance-eliminates need for external compensation in optocoupler-driven feedback networks. |
| Ultra-low quiescent current | 60 µA minimum cathode current-enables energy-efficient standby regulation in always-on vehicle subsystems. |
| Low output impedance | 0.2 Ω typical-reduces sensitivity to PCB trace resistance and improves noise rejection in noisy automotive environments. |
Applications
| Automotive DC-DC Feedback | Industrial Isolated PSU |
|---|---|
|
Use Scenario: Regulating 3.3 V output in AEC-Q100-compliant flyback converter for ADAS camera module power supply. IC Role / Device Role / Timing Role: Adjustable shunt reference providing precision feedback to optocoupler, closing primary-side regulation loop. Use Value: 1% initial accuracy and 100 ppm/°C TC ensure ±2.5% output tolerance over full automotive temperature range without calibration. |
Use Scenario: Secondary-side voltage reference in DIN-rail mounted 24 V to 5 V isolated DC-DC converter for PLC I/O modules. IC Role / Device Role / Timing Role: Shunt regulator setting feedback threshold for optocoupler-coupled error amplifier in isolated topology. Use Value: 60 µA minimum cathode current enables reliable regulation even during brown-out events with weak auxiliary winding coupling. |
| Low-Power Sensor Node | Medical Equipment PSU |
|
Use Scenario: Reference source for battery-powered tire pressure monitoring system (TPMS) MCU ADC and LDO enable threshold. IC Role / Device Role / Timing Role: Precision voltage setpoint generator enabling accurate battery voltage monitoring and wake-up logic. Use Value: Sub-100 µA operating current extends coin-cell lifetime while maintaining 1.24 V reference stability across −40 °C to +85 °C. |
Use Scenario: Feedback element in Class II medical-grade 5 V/12 V dual-output isolated power supply for patient-connected monitors. IC Role / Device Role / Timing Role: Safety-critical shunt reference ensuring regulated output compliance with IEC 60601-1 creepage and leakage constraints. Use Value: AEC-Q100 qualification correlates with high-reliability process controls, supporting long-term field reliability and audit readiness. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACDBVR | 2% initial precision, no AEC-Q100 qualification, higher 100 µA min. cathode current, 0.22 Ω impedance | Approved for industrial/commercial use only; unsuitable for automotive powertrain or safety-critical modules | Select when cost sensitivity outweighs automotive qualification and tighter precision is not required. |
| MAX6008AEUR+T | 0.5% precision, 75 ppm/°C TC, 10 µA max. reference current, but limited 2.5–5.5 V range and no SOT23-5 automotive variant | Designed for low-power sensor interfaces-not optimized for optocoupler drive or high-current shunt operation | Prefer for ultra-low-power analog front-ends where voltage range and load current are constrained. |
Compared with TL431ACDBVR and MAX6008AEUR+T, the TS431AILT uniquely combines AEC-Q100 qualification, 1% precision, 1.24 V low-end regulation, and 60 µA minimum cathode current in SOT23-5-making it the only drop-in solution for automotive flyback feedback requiring both robustness and flexibility.
Availability
TS431AILT is available at Aetrix Electronics and suitable for automotive power supply feedback, industrial isolated DC-DC converters, and low-power sensor node regulation requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TS431AILT 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 management ICs, analog components, and automotive-grade devices.
The TS431 belongs to ST's precision analog reference product line, engineered specifically for automotive and industrial power conversion systems demanding high accuracy, wide temperature operation, and long-term stability.
FAQ
What is the minimum cathode current required for regulation in TS431AILT?
The TS431AILT achieves stable regulation at a minimum cathode current of 60 µA, verified across −40 °C to +125 °C. This value is specified in Table 2 of the official datasheet (DocID5558 Rev 12) under "Operating Conditions" and confirmed by test data in Figure 7 showing functional regulation down to 60 µA at all temperatures.
Can TS431AILT replace TL431 in existing designs?
TS431AILT is pin-compatible with TL431 in SOT23-5 footprint only if the TL431 variant used is also in SOT23-5 (e.g., TL431ACDBVR). However, due to its lower 1.24 V minimum operating voltage and 60 µA vs. 100 µA minimum cathode current, layout review and transient testing are required-especially in low-voltage or light-load conditions.
Does TS431AILT require external compensation for stability?
No external compensation is required. The TS431AILT is designed for unconditional stability with any capacitive load, as stated in the "Features" section and validated in Figure 14 (phase/gain vs. frequency) showing >50° phase margin up to 1 MHz. This eliminates compensation components in optocoupler feedback paths.
What does the 'A' in TS431AILT signify?
The 'A' denotes 1% initial output voltage precision at 25 °C, per Table 8 ("Order codes") in the datasheet. The 'I' indicates industrial temperature range (−40 °C to +125 °C), 'L' specifies SOT23-5 package, and 'T' denotes tape-and-reel packaging-fully aligned with ST's standardized ordering nomenclature.
TS431AILT 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:
- ±1%
- 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:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
TS431AILT FAQ
1.How can I place an order for TS431AILT through Aetrix?
Please submit a Request for Quotation (RFQ) for TS431AILT 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 TS431AILT reliable?
The price and inventory of TS431AILT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TS431AILT is usually 5 days.
3.What payment methods are accepted for TS431AILT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TS431AILT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TS431AILT?
TS431AILT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TS431AILT 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 TS431AILT?
For technical support, including TS431AILT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TS431AILT requirements.
6.How does Aetrix verify that TS431AILT is sourced from the original manufacturer or authorized distributors?
All TS431AILT 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 TS431AILT meets industry standards.
7.What is the process for return or replacement of TS431AILT?
All TS431AILT units undergo pre-shipment inspection (PSI). If there is an issue with TS431AILT, 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 TS431AILT part is unused and in its original packaging.
Return procedure for TS431AILT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TS431AILT Tags
-
TL431AIDBZR
Texas Instruments
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TL431BQDBZR
Texas Instruments
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AN431AN-ATRG1
Diodes Incorporated
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LM4040CYM3-2.5-TR
Microchip Technology
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LM4040CYM3-4.1-TR
Microchip Technology
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LM4040EIM3-2.5/NOPB
Texas Instruments
-
AZ431LBNTR-G1
Diodes Incorporated
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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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