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

STMicroelectronics TL431ACL5T

Name: TL431ACL5T
Brand: STMicroelectronics
SKU: TL431ACL5T
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: TL431ACL5T

Manufacturer:: STMicroelectronics

Category:: Voltage Reference

Package:: SC-74A, SOT-753

Datasheet:: TL431ACL5T.pdf

Description:: IC VREF SHUNT ADJ 1% SOT23-5

Quantity:: RFQ Add To RFQ list

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Inventory:14,990

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Product details

Overview

TL431ACL5T from STMicroelectronics is an AEC-Q100 qualified automotive-grade adjustable shunt voltage reference in SOT23-5 package, delivering 1% initial voltage precision (2.47–2.52 V at 25 °C), −40 °C to +125 °C operating range, 0.22 Ω typical dynamic impedance, and 1–100 mA sink current capability. It serves as the precision feedback element in isolated DC-DC converters, battery management systems, and automotive power supply supervision circuits.

For engineers reviewing the TL431ACL5T datasheet, TL431ACL5T pinout, TL431ACL5T application, or TL431ACL5T equivalent, key selection criteria include its automotive temperature rating, SOT23-5 thermal resistance (67 °C/W junction-to-case), cathode-anode voltage tolerance (37 V), and reference input current stability (≤6.5 µA over temperature).

Technical Context

The TL431ACL5T implements a precision 2.5 V bandgap reference with buffered error amplifier output, configured as a 3-terminal shunt regulator. Its internal architecture enables programmable output voltages from 2.5 V to 36 V using two external resistors while maintaining regulation across 1–100 mA cathode current.

It features low dynamic impedance (0.22 Ω typ.) and high rejection of cathode-anode voltage variation (−2.7 to −1.4 mV/V), ensuring stable reference performance under varying load and input conditions in automotive power rails and industrial feedback loops.

Key Specifications

Parameter	Value and Actual Design Meaning
Reference Voltage	2.47–2.52 V at 25 °C (1% accuracy grade); sets precise feedback threshold for closed-loop regulation
Temp Range	−40 °C to +125 °C (AEC-Q100 qualified); supports under-hood and powertrain applications
Sink Current	1–100 mA cathode current; enables direct drive of optocoupler LEDs or error amplifier loads
Dynamic Impedance	0.22 Ω typical; minimizes output voltage perturbation during transient load steps
V_KA Max	37 V cathode-to-anode rating; allows use in 24 V and 36 V automotive systems with margin
Ref Input Current	≤6.5 µA max over temp; reduces resistor-divider power loss and voltage error
Thermal Resistance	67 °C/W junction-to-case (SOT23-5); enables >150 mW dissipation at 50 °C ambient

Pinout & Package

SOT23-5 plastic micropackage (5-pin, 0.95 mm pitch), surface-mount, RoHS-compliant, ECOPACK2 certified. Dimensions: 2.80 × 1.50 × 1.30 mm (L × W × H), 0.10–0.60 mm lead length.

Pin/Terminal	Circuit Role	Design Meaning
Cathode (Pin 1)	Current sink output	Connects to primary-side feedback node; carries full regulation current (1–100 mA)
Ref (Pin 2)	Precision reference input	High-impedance node (≤6.5 µA) tied to resistor divider midpoint; sets regulated voltage
Anode (Pin 3)	Return path	Low-impedance ground reference for internal amplifier; connects to system GND or secondary-side return
NC (Pin 4)	No connect	Internally unconnected; must be left floating or tied to GND per layout best practice
NC (Pin 5)	No connect	Internally unconnected; no electrical function; avoid routing signals nearby

Key Features

Feature	Design Value
AEC-Q100 qualification	Validated for automotive applications including engine control, ADAS power supplies, and body electronics
Adjustable output range	2.5–36 V via external R1/R2 divider; eliminates need for multiple fixed-voltage references
Low temperature drift	±7 mV max ∆V_ref over −40 to +125 °C; ensures stable feedback across full vehicle operating envelope
High cathode voltage tolerance	37 V absolute max V_KA; supports 24 V battery systems with load-dump transients
Stable capacitive loading	Compatible with ≥10 µF output capacitance without oscillation; simplifies EMI filter design

Applications

Automotive DC-DC Converter Feedback

Battery Management System Reference

Use Scenario: Isolated flyback converter in 12 V/48 V dual-battery architecture.

IC Role / Device Role / Timing Role: Shunt reference providing precise feedback to optocoupler-driven PWM controller.

Use Value: 1% voltage accuracy and −40 to +125 °C stability ensure ±1.5% output regulation across all driving conditions.

Use Scenario: Cell voltage monitoring and balancing circuit in EV traction battery pack.

IC Role / Device Role / Timing Role: Precision reference for ADC input scaling and overvoltage comparator thresholds.

Use Value: Low 6.5 µA max I_ref minimizes quiescent current in always-on monitoring subsystems.

Industrial Power Supply Supervisor

Programmable LED Driver Reference

Use Scenario: Redundant 24 V power rail supervisor in PLC backplane.

IC Role / Device Role / Timing Role: Adjustable shunt regulator detecting undervoltage/overvoltage faults via resistor ladder.

Use Value: 37 V V_KA rating withstands 30 V transients; 0.22 Ω Z_KA ensures fast fault response time.

Use Scenario: Constant-current LED driver with dimming interface in automotive lighting module.

IC Role / Device Role / Timing Role: Reference source for current-sense amplifier and PWM dimming comparator.

Use Value: SOT23-5 footprint enables compact layout; 100 mA sink capability drives high-brightness LED strings directly.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TL431CL5T	2% initial accuracy (2.44–2.55 V), same SOT23-5 package and −40 to +125 °C range	Acceptable where tighter regulation is not required; lower cost for non-safety-critical functions	Select when BOM cost sensitivity outweighs 1% vs. 2% accuracy impact on system tolerance stack-up
TL432ACL5T	Identical electrical specs but includes internal 2.5 V reference bypass capacitor; same pinout and marking L18	Reduces external decoupling needs in space-constrained layouts; improves high-frequency noise immunity	Prefer for new designs where board area is limited or EMI robustness is critical in noisy automotive environments

Compared with TL431CL5T, the TL431ACL5T provides tighter initial tolerance for improved system-level accuracy; compared with TL432ACL5T, it lacks the integrated bypass capacitor but offers identical regulation performance at lower unit cost.

Availability

TL431ACL5T is available at Aetrix Electronics and suitable for automotive power supplies, battery management systems, and industrial supervisory circuits requiring stable component supply with AEC-Q100 compliance and extended temperature operation.

Supply support for TL431ACL5T 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 automotive, industrial, and consumer markets.

The TL431/TL432 product line delivers precision programmable shunt references optimized for automotive-grade reliability, wide current range operation, and seamless integration into feedback networks of isolated power converters and safety-critical monitoring systems.

FAQ

What is the maximum cathode-to-anode voltage the TL431ACL5T can withstand?

The TL431ACL5T has an absolute maximum cathode-to-anode voltage (V_KA) rating of 37 V. This allows safe operation in 24 V automotive systems experiencing load-dump transients up to 35 V, with 2 V design margin. Exceeding 37 V risks permanent device failure due to junction breakdown.

How does the SOT23-5 package affect thermal performance compared to SO-8?

The TL431ACL5T in SOT23-5 exhibits a junction-to-case thermal resistance (R_thjc) of 67 °C/W, versus 30 °C/W for the SO-8 variant. This means at 100 mA sink current and 30 V V_KA, the SOT23-5 version dissipates ~3 W and experiences ~200 °C junction rise above case-requiring careful PCB copper pour design. SO-8 is preferred for >150 mW continuous dissipation.

Can TL431ACL5T replace TL431ACD in existing SO-8 designs?

No-TL431ACL5T uses SOT23-5 packaging with different pinout (Cathode/Ref/Anode/NC/NC) versus SO-8's 8-pin layout (Anode/Cathode/Ref/NC/NC/NC/NC/NC). Direct replacement requires PCB redesign, footprint change, and signal re-routing. For drop-in compatibility, select TL431ACDT (SO-8, tape-and-reel) instead.

What is the minimum cathode current required for regulation stability?

The TL431ACL5T requires a minimum cathode current (I_min) of 0.5 mA at 25 °C and up to 0.6 mA across −40 to +125 °C to maintain regulation. Below this, the reference voltage becomes unstable and may deviate by >10%. Designers must ensure resistor divider bias current plus load current exceeds this threshold under all operating conditions.

TL431ACL5T 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):: 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:: 600 µA

Operating Temperature:: 0°C ~ 70°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-5

TL431ACL5T FAQ

1.How can I place an order for TL431ACL5T through Aetrix?

Please submit a Request for Quotation (RFQ) for TL431ACL5T 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 TL431ACL5T reliable?

The price and inventory of TL431ACL5T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431ACL5T is usually 5 days.

3.What payment methods are accepted for TL431ACL5T?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431ACL5T transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for TL431ACL5T?

TL431ACL5T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your TL431ACL5T 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 TL431ACL5T?

For technical support, including TL431ACL5T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431ACL5T requirements.

6.How does Aetrix verify that TL431ACL5T is sourced from the original manufacturer or authorized distributors?

All TL431ACL5T 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 TL431ACL5T meets industry standards.

7.What is the process for return or replacement of TL431ACL5T?

All TL431ACL5T units undergo pre-shipment inspection (PSI). If there is an issue with TL431ACL5T, 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 TL431ACL5T part is unused and in its original packaging.

Return procedure for TL431ACL5T:

1.Submit a request within 90 days.

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

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