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Nexperia USA Inc. TL431FDT-QR
- Part No.:
- TL431FDT-QR
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TL431FDT-QR.pdf
- Description:
- IC VREF SHUNT 2.495V SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:4,456
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Product details
Overview
TL431FDT-QR from Nexperia is a three-terminal adjustable precision shunt regulator with 0.5 % reference voltage tolerance (2.483 V to 2.507 V at 10 mA), rated for -40 °C to +125 °C operation, and packaged in SOT23 with normal pinning (K-REF-A). It delivers sink current from 1 mA to 100 mA, features 0.2 Ω dynamic cathode-anode impedance, and is AEC-Q100 Grade 1 qualified for automotive feedback loops.
For engineers reviewing the TL431FDT-QR datasheet, TL431FDT-QR pinout, TL431FDT-QR application, or TL431FDT-QR equivalent, this device is selected for high-stability voltage reference, isolated SMPS feedback, and precision current sinking where tight Vref tolerance and extended temperature range are mandatory.
Technical Context
The TL431FDT-QR implements an internal bandgap reference, error amplifier, and NPN output stage in a single monolithic IC. Its functional diagram shows direct cathode–anode regulation controlled by the REF terminal, enabling programmable output voltages from 2.495 V to 36 V using two external resistors.
It operates as a 3-terminal shunt regulator with active turn-on behavior-distinct from passive Zener diodes-delivering sharp regulation onset, low output noise, and stable performance across its full -40 °C to +125 °C junction temperature range under 100 mA sink load.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference voltage (Vref) | 2.483 V to 2.507 V at IK = 10 mA - defines minimum programmable output voltage and sets accuracy baseline for external resistor divider |
| Cathode current range | 1 mA to 100 mA - supports both low-power biasing and high-current shunt regulation without external buffering |
| Dynamic cathode-anode impedance | 0.2 Ω typical below 1 kHz - ensures minimal output voltage deviation under transient load changes |
| Temperature range | -40 °C to +125 °C - enables use in engine control units, battery management, and under-hood automotive modules |
| AEC-Q100 qualification | Grade 1 (−40 °C to +125 °C) - confirms reliability for automotive powertrain and chassis applications |
| Output voltage adjustability | 2.495 V to 36 V via two external resistors - allows flexible system-level voltage setting without discrete Zener selection |
| Reference current (Iref) | 2.0 µA to 4.0 µA - determines minimum bias current required at REF pin for stable regulation |
Pinout & Package
SOT23 plastic surface-mounted package (3 leads), 1.9 mm × 1.1 mm footprint, 0.45 mm nominal height; standard JEDEC outline per Figure 27.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - K (Cathode) | Current sink output | Primary current path; connects to regulated rail or SMPS optocoupler LED anode; must handle up to 100 mA continuous |
| 2 - REF (Reference) | Voltage sense input | High-impedance node (2–4 µA max) that compares external divider voltage to internal 2.495 V bandgap; determines regulation setpoint |
| 3 - A (Anode) | Return path / ground reference | Low-impedance return for cathode current; ties to system ground or negative rail; forms closed regulation loop with REF and K |
Key Features
| Feature | Design Value |
|---|---|
| 0.5 % reference voltage tolerance | Enables ±0.012 V absolute Vref error at 25 °C, reducing calibration overhead in safety-critical voltage monitoring |
| 0.2 Ω dynamic output impedance | Maintains <1 mV output shift under 10 mA load transients-critical for stable optocoupler drive in isolated SMPS |
| Extended temperature operation | Validated performance from −40 °C to +125 °C eliminates derating concerns in under-hood or industrial ambient conditions |
| AEC-Q100 Grade 1 qualification | Confirms robustness against thermal cycling, ESD (4 kV HBM), and long-term reliability for automotive production deployment |
| Programmable 2.495 V–36 V output | Replaces multiple Zener diodes with one part, simplifying BOM and enabling field-adjustable outputs via resistor change |
Applications
| Automotive Engine Control Unit (ECU) Voltage Reference | Isolated Flyback SMPS Feedback |
|---|---|
Use Scenario: Providing stable 5.0 V reference for microcontroller ADC and sensor biasing in gasoline/diesel ECUs. IC Role / Device Role / Timing Role: Shunt regulator establishing precise, temperature-stable reference rail independent of main 12 V battery fluctuations. Use Value: 0.5 % Vref tolerance and −40 °C to +125 °C operation ensure ADC accuracy remains within 1 LSB across full vehicle operating envelope. |
Use Scenario: Closing regulation loop in 24 V input/5 V output flyback converter with optocoupler isolation. IC Role / Device Role / Timing Role: Precision shunt element driving optocoupler LED to transmit secondary-side voltage error signal to primary-side PWM controller. Use Value: 0.2 Ω output impedance minimizes feedback delay and improves transient response; AEC-Q100 qualification validates reliability in safety-critical power systems. |
| Precision Constant Current Sink for LED Driver | Industrial Sensor Excitation Circuit |
Use Scenario: Delivering 20 mA constant current to high-brightness indicator LEDs in dashboard clusters. IC Role / Device Role / Timing Role: Shunt-based current sink configured with single series resistor; REF tied to fixed voltage, K sinks current through LED to A. Use Value: Tight Vref tolerance ensures ±0.1 mA current accuracy over temperature-eliminating visible brightness drift in cabin lighting. |
Use Scenario: Supplying excitation current to 350 Ω RTD bridge in industrial temperature transmitter modules. IC Role / Device Role / Timing Role: Programmable shunt regulator configured as precision current source (via REF-to-ground resistor) to bias RTD with 1.000 mA. Use Value: 2.495 V reference and 0.5 % tolerance yield 1.000 mA ±0.005 mA excitation, directly limiting RTD measurement uncertainty to <0.015 °C. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431AFDT-Q | 1.0 % Vref tolerance (2.470 V–2.520 V); same SOT23 normal pinning and −40 °C to +125 °C rating | Acceptable where ±12.5 mV reference error is sufficient (e.g., non-safety-critical power rails) | Select when cost sensitivity outweighs need for 0.5 % accuracy; identical layout and thermal profile |
| TL431BFDT-Q | Identical 0.5 % Vref spec and pinout; differs only in marking code (AT% vs AR%) and internal lot traceability | No functional difference; used interchangeably in same automotive platforms per Nexperia documentation | Valid drop-in replacement with identical electrical, thermal, and qualification status-no redesign needed |
Compared with TL431AFDT-Q, TL431FDT-QR provides tighter reference accuracy critical for high-resolution sensing; compared with TL431BFDT-Q, it shares identical performance but may differ in manufacturing batch origin and regional distribution channel.
Availability
TL431FDT-QR is available at Aetrix Electronics and suitable for automotive engine control units, isolated switch-mode power supplies, and industrial sensor excitation circuits requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TL431FDT-QR 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
Nexperia is a global semiconductor expert focused on high-volume, high-reliability logic, analog, and MOSFET solutions, with leadership in automotive-qualified components and efficient manufacturing.
TL431FDT-QR belongs to the TL431-Q family of AEC-Q100 qualified shunt regulators, designed specifically for automotive and industrial applications demanding precision voltage reference, robust thermal stability, and long-term supply assurance.
FAQ
What is the maximum cathode-anode voltage for TL431FDT-QR?
The absolute maximum cathode-anode voltage (VKA) is 37 V per IEC 60134 limiting values. The recommended operating range is Vref to 36 V. Exceeding 37 V risks permanent damage; operation above 36 V is not guaranteed for regulation stability or long-term reliability.
Can TL431FDT-QR be used in place of a Zener diode?
Yes-TL431FDT-QR replaces Zener diodes in shunt regulation roles with superior performance: sharper turn-on, lower dynamic impedance (0.2 Ω vs typical Zener's >5 Ω), and programmable output from 2.495 V to 36 V using two resistors instead of discrete voltage selection.
What is the minimum cathode current required for regulation?
The minimum cathode current (IK(min)) is 0.4 mA at −40 °C to +125 °C, per Table 12 characteristics. Below this, regulation degrades; design must ensure ≥0.6 mA under worst-case conditions to maintain 0.5 % Vref accuracy across temperature.
Does TL431FDT-QR require an input capacitor for stability?
No bulk input capacitor is required, but a 100 pF capacitor at the REF pin is recommended per Figure 26 to suppress high-frequency noise coupling from optocoupler or switching nodes-especially in SMPS feedback applications where noise-induced oscillation must be avoided.
TL431FDT-QR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- 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):
- 2.495V
- Voltage - Output (Max):
- 36 V
- Current - Output:
- 100 mA
- Tolerance:
- ±2%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 1 mA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3 (TO-236)
TL431FDT-QR FAQ
1.How can I place an order for TL431FDT-QR through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431FDT-QR 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 TL431FDT-QR reliable?
The price and inventory of TL431FDT-QR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431FDT-QR is usually 5 days.
3.What payment methods are accepted for TL431FDT-QR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431FDT-QR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431FDT-QR?
TL431FDT-QR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431FDT-QR 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 TL431FDT-QR?
For technical support, including TL431FDT-QR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431FDT-QR requirements.
6.How does Aetrix verify that TL431FDT-QR is sourced from the original manufacturer or authorized distributors?
All TL431FDT-QR 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 TL431FDT-QR meets industry standards.
7.What is the process for return or replacement of TL431FDT-QR?
All TL431FDT-QR units undergo pre-shipment inspection (PSI). If there is an issue with TL431FDT-QR, 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 TL431FDT-QR part is unused and in its original packaging.
Return procedure for TL431FDT-QR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431FDT-QR Tags
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