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STMicroelectronics TL431CCT
- Part No.:
- TL431CCT
- Manufacturer:
- STMicroelectronics
- Category:
- Voltage Reference
- Package:
- 6-TSSOP, SC-88, SOT-363
- Datasheet:
-
TL431CCT.pdf
- Description:
- IC VREF SHNT ADJ 2.21% SOT323-6L
- Quantity:
- Payment:
- Shipping:
Inventory:5,881
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Product details
Overview
TL431CCT from STMicroelectronics is an AEC-Q100 qualified automotive-grade adjustable shunt voltage reference in SOT323-6 package, delivering 2.5–36 V programmable output with ±2% initial accuracy, 1 mA to 100 mA sink current capability, and 0.22 Ω typical dynamic impedance - used for precision feedback in isolated DC-DC converters and automotive power supply regulation.
For engineers reviewing the TL431CCT datasheet, TL431CCT pinout, TL431CCT application, or TL431CCT equivalent, key selection criteria include its -40 °C to +125 °C operating range, SOT323-6 thermal resistance (Rthja = 221 °C/W), cathode-anode voltage rating (37 V), and reference input current (≤5.2 µA at 25 °C).
Technical Context
The TL431CCT implements a precision 2.5 V internal bandgap reference with high-gain error amplifier and NPN output stage, configured as a 3-terminal shunt regulator where cathode-anode voltage is set by external resistor divider on the REF pin. Its operation requires minimum 0.5 mA cathode current for regulation and maintains stable output despite input voltage variation up to 36 V.
It features low temperature drift (±17 mV over -40 °C to +125 °C), minimal load regulation error due to 0.22 Ω dynamic impedance, and inherent stability with capacitive loads up to 10 µF - enabling direct use in flyback SMPS feedback loops without additional compensation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.5 V nominal, ±2% tolerance at 25 °C - sets absolute accuracy of regulated output voltage in feedback networks. |
| Output Voltage Range | 2.5 V to 36 V via external resistors - enables flexible design of both low- and high-voltage regulated supplies. |
| Sink Current Range | 1 mA to 100 mA - supports direct drive of optocoupler LEDs or error amplifier biasing in isolated topologies. |
| Dynamic Impedance | 0.22 Ω typical - ensures tight load regulation and fast transient response under varying cathode current. |
| Temp. Range | -40 °C to +125 °C - validated for under-hood automotive applications including engine control and ADAS power modules. |
| VK-A Max | 37 V - defines maximum allowable cathode-to-anode voltage, critical for input surge protection design. |
| IREF Max | 5.2 µA at 25 °C - determines minimum pull-up resistor value for REF pin in high-impedance feedback configurations. |
Pinout & Package
SOT323-6 plastic surface-mount package (3.2 mm × 1.35 mm × 0.95 mm), lead-free and RoHS-compliant per ECOPACK® standards, with 221 °C/W junction-to-ambient thermal resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode | Output current sink terminal | Connects to primary-side optocoupler LED or feedback node; carries full regulated output current. |
| Anode | Current return path | Connected to system ground or low-side reference; completes shunt current loop. |
| REF | Reference input sensing node | High-impedance input monitoring voltage divider; triggers regulation when ≥2.5 V applied. |
| NC (Pin 4) | No connect | Internally unconnected; must remain floating or grounded per layout best practices. |
| NC (Pin 5) | No connect | Internally unconnected; no electrical function; avoid routing signals here. |
| NC (Pin 6) | No connect | Internally unconnected; unused pad; may be tied to ground for mechanical stability only. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q100 qualification | Qualified for automotive applications per Grade 1 (-40 °C to +125 °C), enabling use in safety-critical power systems. |
| Adjustable output | Programmable 2.5–36 V output using two external resistors - eliminates need for multiple fixed-voltage references. |
| Low dynamic impedance | 0.22 Ω typical - minimizes output voltage deviation during load transients in SMPS feedback paths. |
| Wide sink current range | 1–100 mA operation - supports direct optocoupler drive without external transistor buffering. |
| Stable with capacitive loads | Compatible with ≥10 µF output capacitance - simplifies EMI filter design in automotive DC-DC stages. |
Applications
| Automotive Power Supply | Industrial Isolated PSU |
|---|---|
Use Scenario: Feedback regulation in 12 V/48 V dual-battery automotive DC-DC converters powering infotainment and ADAS ECUs. IC Role / Device Role / Timing Role: Shunt voltage reference providing precise 2.5 V threshold for optocoupler-based secondary-side feedback. Use Value: Maintains ±2% output accuracy across -40 °C to +125 °C ambient, meeting ISO 16750-2 requirements for under-hood environments. |
Use Scenario: Secondary-side regulation in industrial 24 V AC/DC power supplies with reinforced isolation for PLC I/O modules. IC Role / Device Role / Timing Role: Adjustable shunt reference setting output voltage via resistor divider, interfacing with linear optocoupler. Use Value: Enables single-BOM flexibility across 12–48 V output variants while maintaining <1% load regulation error. |
| Server PSU Monitoring | EV Battery Management |
Use Scenario: Precision voltage supervision in redundant 12 V server power supplies detecting overvoltage/undervoltage faults. IC Role / Device Role / Timing Role: Reference comparator input for analog fault detection circuitry monitoring rail integrity. Use Value: Delivers 0.22 Ω dynamic impedance and ≤5.2 µA reference current, minimizing sensing error in high-impedance monitor paths. |
Use Scenario: Cell-balancing reference in high-voltage EV battery packs (400–800 V) requiring accurate mid-point voltage sampling. IC Role / Device Role / Timing Role: High-stability shunt reference generating precise 2.5 V reference for differential ADC inputs measuring cell voltages. Use Value: ±17 mV reference drift over full temperature range ensures <0.1% measurement error in BMS voltage acquisition. |
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 | ±1% initial accuracy (vs. ±2%); otherwise identical SOT323-6 footprint, temp range, and electrical specs. | Preferred where tighter output tolerance is required without changing PCB layout or thermal design. | Select TL431ACCT when system-level voltage accuracy budget demands <1% regulation error at room temperature. |
| TL431ICT | Same ±2% accuracy but rated for -40 °C to +105 °C (vs. +125 °C); otherwise identical pinout and performance. | Lower-cost option for non-under-hood automotive modules (e.g., body control units) where max ambient is ≤105 °C. | Choose TL431ICT for cost-sensitive industrial or cabin electronics where extended high-temp operation is unnecessary. |
Compared with TL431CCT, TL431ACCT improves reference accuracy without thermal or packaging trade-offs, while TL431ICT reduces cost and qualification scope by limiting max operating temperature - enabling optimized selection based on accuracy and environmental requirements.
Availability
TL431CCT is available at Aetrix Electronics and suitable for automotive power supply, industrial isolated PSU, and EV battery management systems requiring stable component supply with AEC-Q100 compliance and extended temperature support.
Supply support for TL431CCT 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 product line delivers precision programmable shunt references optimized for feedback control in isolated power conversion, emphasizing automotive qualification, wide operating range, and robustness in harsh environments.
FAQ
What is the minimum cathode current required for regulation in TL431CCT?
The TL431CCT requires a minimum cathode current of 0.5 mA at 25 °C to maintain regulation, increasing to 1 mA at extremes of the -40 °C to +125 °C operating range. This ensures stable reference behavior when driving optocouplers with high CTR or high-value feedback dividers.
Can TL431CCT be used in place of TL431CD in SO-8 packages?
No - TL431CCT uses SOT323-6 packaging with different pinout, thermal characteristics (Rthja = 221 °C/W vs. 85 °C/W for SO-8), and layout requirements. Direct substitution requires PCB redesign; functional equivalence exists only in electrical parameters, not mechanical compatibility.
Does TL431CCT support capacitive loads on the cathode node?
Yes - the TL431CCT remains stable with up to 10 µF capacitive loading on the cathode, as verified in Figure 21 of the datasheet. This allows direct integration with bulk output capacitors in flyback converters without external phase compensation.
What is the maximum cathode-to-anode voltage rating for TL431CCT?
The absolute maximum cathode-to-anode voltage (VK-A) is 37 V, with recommended operating limit at 36 V. Exceeding this risks permanent damage; designs must ensure transient clamping or input filtering to prevent voltage spikes beyond this rating.
TL431CCT 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:
- ±2.21%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 1 mA
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-323-6L
TL431CCT FAQ
1.How can I place an order for TL431CCT through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431CCT 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 TL431CCT reliable?
The price and inventory of TL431CCT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431CCT is usually 5 days.
3.What payment methods are accepted for TL431CCT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431CCT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431CCT?
TL431CCT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431CCT 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 TL431CCT?
For technical support, including TL431CCT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431CCT requirements.
6.How does Aetrix verify that TL431CCT is sourced from the original manufacturer or authorized distributors?
All TL431CCT 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 TL431CCT meets industry standards.
7.What is the process for return or replacement of TL431CCT?
All TL431CCT units undergo pre-shipment inspection (PSI). If there is an issue with TL431CCT, 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 TL431CCT part is unused and in its original packaging.
Return procedure for TL431CCT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431CCT Tags
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LM4040DIM3X-2.5/NOPB
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AZ431LANTR-G1
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