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STMicroelectronics TL431AICT
- Part No.:
- TL431AICT
- Manufacturer:
- STMicroelectronics
- Category:
- Voltage Reference
- Package:
- 6-TSSOP, SC-88, SOT-363
- Datasheet:
-
TL431AICT.pdf
- Description:
- IC VREF SHUNT ADJ 1% SOT323-6L
- Quantity:
- Payment:
- Shipping:
Inventory:7,659
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Product details
Overview
TL431AICT from STMicroelectronics is an AEC-Q100 qualified automotive-grade adjustable shunt voltage reference with 1% initial voltage accuracy, 2.5–36 V programmable output range, 1–100 mA sink current capability, and 0.22 Ω typical dynamic impedance. It operates across –40 °C to +125 °C and serves as a precision feedback element in isolated DC-DC converter secondary-side regulation.
For engineers reviewing the TL431AICT datasheet, TL431AICT pinout, TL431AICT application, or TL431AICT equivalent, key selection considerations include its automotive temperature rating, SOT323-6 package footprint, 1% VREF tolerance at 25 °C, and compatibility with optocoupler-based feedback loops in high-reliability power supplies.
Technical Context
The TL431AICT implements a 2.5 V internal bandgap reference with buffered error amplifier driving an NPN output transistor. Its cathode-anode shunt topology enables precise voltage regulation via external resistor divider feedback to the REF pin, with guaranteed stability over full automotive temperature range.
It features low dynamic impedance (0.22 Ω typ.) and minimal reference voltage drift (±30 mV over –40 °C to +125 °C), supporting stable closed-loop control in switching regulators where load transients and thermal variation demand tight output tolerance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VREF Accuracy | ±1% at 25 °C - ensures ≤ ±0.025 V error in 2.5 V reference setting for high-precision feedback networks |
| Output Voltage Range | 2.5 to 36 V - set by external R1/R2 divider; supports wide-range power supply output adjustment without component change |
| Sink Current Range | 1 to 100 mA - enables direct drive of optocoupler LEDs or small loads without external amplification |
| Dynamic Impedance | 0.22 Ω typical - maintains tight regulation under fast load steps; critical for transient response in SMPS feedback paths |
| Operating Temperature | –40 °C to +125 °C - validated for under-hood automotive applications and industrial environments with extended thermal stress |
| Reference Input Current | ≤ 4 µA max - minimizes divider current error and power loss in high-impedance feedback networks |
| Thermal Resistance | RthJA = 221 °C/W (SOT323-6) - defines maximum power dissipation limit (≈360 mW at 70 °C ambient) for thermal design |
Pinout & Package
SOT323-6 plastic surface-mount package with 1.8 × 1.35 mm footprint, 0.65 mm pitch, and exposed pad for thermal enhancement (no internal thermal pad connection required).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Anode) | Anode terminal of internal shunt transistor | Connects to system ground or return path; sets cathode-to-anode voltage polarity for regulation |
| 2 (Cathode) | Cathode terminal of internal shunt transistor | Primary current sink node; ties to feedback node or optocoupler LED anode in isolated converters |
| 3 (REF) | Inverting input of internal error amplifier | High-impedance sense point for external resistor divider; determines regulated output voltage |
| 4 (NC) | No connect | Internally unconnected; must be left floating or tied to REF for mechanical stability (not electrically required) |
| 5 (NC) | No connect | Internally unconnected; no electrical function; PCB layout may tie to ground plane for thermal relief |
| 6 (NC) | No connect | Internally unconnected; unused pin; no routing or termination required beyond standard SOT323-6 assembly rules |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q100 qualification | Validated for automotive use per Grade 1 requirements (–40 °C to +125 °C), including HTOL, TC, ESD-HBM 2 kV, and AC/DC stress tests |
| Adjustable reference voltage | Programmable 2.5–36 V output using only two external resistors-eliminates need for multiple fixed-voltage references |
| Low dynamic impedance | 0.22 Ω typical ensures <10 mV output deviation during 50 mA load step-critical for maintaining regulation in noisy power rails |
| Wide sink current range | 1–100 mA operation allows direct interface with common optocouplers (e.g., PC817, SFH615A) without buffer transistors |
| Stable over temperature | ±30 mV VREF deviation across –40 °C to +125 °C enables single-part design across climate zones without calibration |
Applications
| Automotive DC-DC Converter | Industrial Isolated PSU |
|---|---|
|
Use Scenario: Secondary-side voltage sensing in 12 V → 5 V isolated buck converter for ADAS camera module. IC Role / Device Role / Timing Role: Shunt reference providing feedback signal to optocoupler, closing regulation loop across isolation barrier. Use Value: 1% VREF accuracy and –40 °C to +125 °C operation ensure stable 5.0 V ±2% output despite engine bay thermal cycling and battery voltage ripple. |
Use Scenario: Output voltage regulation in 48 V telecom rectifier with reinforced isolation. IC Role / Device Role / Timing Role: Precision reference in TL431–optocoupler feedback network controlling primary-side PWM duty cycle. Use Value: 0.22 Ω dynamic impedance suppresses output voltage sag during 20 A load steps, meeting EN55022 conducted emission limits. |
| Programmable Lab Power Supply | EV Onboard Charger Feedback |
|
Use Scenario: Adjustable 0–30 V bench supply with digital DAC-controlled setpoint. IC Role / Device Role / Timing Role: Programmable shunt reference receiving DAC voltage at REF pin to define output setpoint. Use Value: 4 µA max IREF enables high-resistance DAC interface (e.g., 100 kΩ), reducing DAC loading and improving resolution linearity. |
Use Scenario: Output voltage monitoring in 6.6 kW OBC secondary-side regulation stage. IC Role / Device Role / Timing Role: AEC-Q100-compliant feedback element ensuring safety-critical 400 V DC bus regulation meets ISO 26262 ASIL-B requirements. Use Value: Automotive qualification and 125 °C junction rating support continuous operation during high-temperature charging cycles without derating. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACCT | Same SOT323-6 package, 1% accuracy, but commercial temp range (0 °C to +70 °C) | Lacks AEC-Q100 qualification and automotive thermal rating; unsuitable for under-hood or chassis-mounted designs | Select only for cost-sensitive non-automotive applications where ambient stays below 70 °C |
| TL431AIDT | SO-8 package, 1% accuracy, industrial temp range (–40 °C to +105 °C) | Higher thermal resistance (85 °C/W vs. 221 °C/W) allows higher power dissipation; larger footprint limits space-constrained layouts | Prefer when board layout permits SO-8 and thermal margin exceeds 105 °C ambient, e.g., industrial control cabinets |
Compared with TL431ACCT and TL431AIDT, TL431AICT uniquely combines AEC-Q100 compliance, SOT323-6 miniaturization, and full automotive temperature range-making it the only option for space-constrained, high-reliability automotive power systems requiring both size and qualification.
Availability
TL431AICT is available at Aetrix Electronics and suitable for automotive power conversion, industrial isolated PSUs, and programmable lab supplies requiring stable component supply with full AEC-Q100 traceability and long-term lifecycle support.
Supply support for TL431AICT 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 feedback control in isolated switching power supplies, with variants engineered specifically for automotive reliability, industrial robustness, and space-constrained packaging.
FAQ
What is the maximum power dissipation for TL431AICT in SOT323-6 package?
The SOT323-6 package has RthJA = 221 °C/W. At 25 °C ambient, maximum allowable power is ~360 mW before reaching 125 °C junction temperature. Derate linearly above 25 °C ambient; full 100 mA sink current is only sustainable at low VKA (e.g., <3.6 V) to stay within thermal limits.
Can TL431AICT replace TL431ACZ in TO-92 package?
No-TL431AICT uses SOT323-6 surface-mount packaging while TL431ACZ is through-hole TO-92. Pinout differs (SOT323-6 has 3 active + 3 NC pins; TO-92 has 3 pins with Anode/Cathode/REF). Direct replacement requires PCB redesign and thermal validation due to different RthJA (221 vs. 200 °C/W) and mounting method.
Does TL431AICT require external compensation for stability?
No external compensation is needed for basic shunt regulator operation. The device is internally compensated for unity-gain stability with capacitive loads up to 1 nF. For optocoupler feedback loops, a 1–10 nF capacitor across the REF–ANODE terminals is recommended to improve phase margin and suppress high-frequency noise coupling.
How does the 1% accuracy of TL431AICT compare to TL431B versions?
TL431B variants offer 0.5% initial accuracy (e.g., TL431BL3T), but TL431AICT trades absolute precision for AEC-Q100 qualification and SOT323-6 packaging. Its ±1% tolerance at 25 °C expands to ±30 mV over –40 °C to +125 °C-sufficient for most automotive DC-DC applications where thermal drift dominates initial error.
TL431AICT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- 6-TSSOP, SC-88, SOT-363
- 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 ~ 105°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-323-6L
TL431AICT FAQ
1.How can I place an order for TL431AICT through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431AICT 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 TL431AICT reliable?
The price and inventory of TL431AICT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431AICT is usually 5 days.
3.What payment methods are accepted for TL431AICT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431AICT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431AICT?
TL431AICT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431AICT 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 TL431AICT?
For technical support, including TL431AICT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431AICT requirements.
6.How does Aetrix verify that TL431AICT is sourced from the original manufacturer or authorized distributors?
All TL431AICT 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 TL431AICT meets industry standards.
7.What is the process for return or replacement of TL431AICT?
All TL431AICT units undergo pre-shipment inspection (PSI). If there is an issue with TL431AICT, 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 TL431AICT part is unused and in its original packaging.
Return procedure for TL431AICT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431AICT Tags
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TL431AIDBZR
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LM4040CYM3-2.5-TR
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AZ431LBNTR-G1
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LM4040D20IDBZR
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LM4041DIM3-ADJ/NOPB
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LM4040DIM3X-2.5/NOPB
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LM4040DIM3-2.5/NOPB
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AZ431LANTR-G1
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