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Nexperia USA Inc. TL431BMFDT-QR
- Part No.:
- TL431BMFDT-QR
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TL431BMFDT-QR.pdf
- Description:
- IC VREF SHUNT 2.495V SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:4,136
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Product details
Overview
TL431BMFDT-QR from Nexperia is a B-grade (±0.5 %) adjustable precision shunt regulator in SOT23 package with mirrored pinning (REF–K–A), rated for −40 °C to +125 °C operation, 2.483 V to 2.507 V reference voltage at 10 mA cathode current, 0.2 Ω dynamic impedance, and AEC-Q100 Grade 1 qualification - used in isolated SMPS feedback loops requiring tight voltage regulation under automotive thermal stress.
For engineers reviewing the TL431BMFDT-QR datasheet, TL431BMFDT-QR pinout, TL431BMFDT-QR application, or TL431BMFDT-QR equivalent, this page delivers verified pin mapping, B-grade tolerance validation, mirrored SOT23 terminal roles, automotive thermal derating curves, and direct substitution guidance against TL431BFDT-Q and TL431AMFDT-Q.
Technical Context
The TL431BMFDT-QR implements a precision bandgap-based shunt reference with internal error amplifier and NPN output stage, enabling programmable regulation from 2.495 V to 36 V via two external resistors. Its mirrored pinout (Pin 1 = REF, Pin 2 = K, Pin 3 = A) distinguishes it from standard-pin variants and mandates correct PCB layout to avoid reverse biasing.
It operates as a 3-terminal active shunt: REF senses voltage divider output, K sinks adjustable current up to 100 mA, and A connects to system ground or return path. The device achieves 9 mV typical reference drift over 0 °C to 70 °C and maintains <0.5 Ω dynamic impedance below 1 kHz - critical for stable feedback in flyback and forward converters.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.483 V to 2.507 V at 10 mA cathode current - defines ±0.5 % initial accuracy for high-precision feedback setpoints |
| Cathode-Anode Voltage Range | 2.495 V to 36 V - sets maximum regulated output voltage using external resistor network |
| Cathode Current Range | 1 mA to 100 mA - determines minimum load requirement and maximum sink capability for loop stability |
| Dynamic Impedance | 0.2 Ω typical below 1 kHz - ensures low AC impedance for noise rejection and phase margin preservation in control loops |
| Temperature Range | −40 °C to +125 °C - supports under-hood automotive environments without derating loss of regulation accuracy |
| Reference Current | 2 µA to 4 µA - establishes minimal bias current draw from voltage divider, reducing power loss in high-impedance networks |
| AEC-Q100 Grade | Grade 1 qualified - validated for automotive applications with junction temperature up to 125 °C ambient |
Pinout & Package
SOT23 plastic surface-mounted package (3 leads), 1.9 mm × 1.1 mm × 1.0 mm body, with mirrored pinning configuration specific to MFDT-Q suffix parts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | REF | Reference input node - connects to midpoint of external resistor divider; high-impedance sense point (2–4 µA max) |
| 2 | K | Cathode terminal - sinks regulated current into ground or return path; must handle up to 100 mA continuous |
| 3 | A | Anode terminal - connects to system ground or low-side return; completes shunt current path and sets common reference |
Key Features
| Feature | Design Value |
|---|---|
| Programmable Output Voltage | 2.495 V to 36 V via two external resistors - eliminates need for multiple fixed-voltage references in multi-rail designs |
| B-Grade Reference Tolerance | ±0.5 % at 25 °C - enables tighter output regulation than standard (±2 %) or A-grade (±1 %) variants in cost-sensitive automotive modules |
| Low Dynamic Impedance | 0.2 Ω typical - minimizes AC gain variation across frequency, improving transient response and loop stability in SMPS feedback |
| Automotive Qualification | AEC-Q100 Grade 1 - certified for engine control units, ADAS power supplies, and body electronics with full traceability |
| Mirrored Pinout Compatibility | REF–K–A sequence (vs. standard K–REF–A) - allows PCB reuse across TL431-Q family while maintaining functional equivalence in layout |
Applications
| Isolated Flyback SMPS Feedback | Precision Current Sink |
|---|---|
|
Use Scenario: Secondary-side voltage sensing in automotive DC/DC converters where primary-side regulation is impractical due to transformer isolation. IC Role / Device Role / Timing Role: Shunt regulator providing precise 2.5 V reference to optocoupler LED driver, closing feedback loop across isolation barrier. Use Value: ±0.5 % B-grade tolerance ensures ≤±0.18 V output deviation at 36 V rail, meeting ASIL-B voltage monitoring requirements. |
Use Scenario: Constant-current biasing of laser diodes in vehicle headlight control modules. IC Role / Device Role / Timing Role: Precision shunt element setting exact current through external sense resistor, independent of supply rail fluctuations. Use Value: 0.2 Ω dynamic impedance suppresses ripple-induced current variation, maintaining <±1 % current stability over 10–100 mA range. |
| On-Board Battery Monitor Reference | Adjustable Overvoltage Protection Threshold |
|
Use Scenario: High-accuracy voltage reference for fuel gauge ICs in 12 V lead-acid and 48 V mild-hybrid battery management systems. IC Role / Device Role / Timing Role: Stable reference source for ADC input scaling, rejecting thermal drift across −40 °C to +125 °C ambient. Use Value: 9 mV typical drift over 0–70 °C and <34 mV max variation over full −40–125 °C range enable ±0.5 % SOC estimation accuracy. |
Use Scenario: Programmable trip point for overvoltage lockout in infotainment power rails exposed to load-dump transients. IC Role / Device Role / Timing Role: Adjustable comparator reference feeding into external logic or gate driver to disable downstream circuitry above safe threshold. Use Value: 2.483–2.507 V B-grade reference combined with resistor ratio yields ±0.3 V absolute OV threshold accuracy at 15 V nominal rail. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BFDT-Q | Same B-grade tolerance (±0.5 %), same SOT23 package, but standard pinning (K–REF–A) | Requires PCB layout revision to match pin 1 = K instead of REF; identical electrical performance | Select when reusing existing standard-pin footprints and avoiding mirrored-layout redesign |
| TL431AMFDT-Q | A-grade tolerance (±1.0 %), mirrored pinning (REF–K–A), same −40 °C to +125 °C rating | Looser initial accuracy but identical thermal and packaging behavior; lower cost than B-grade | Select for non-safety-critical applications where ±1 % regulation suffices and cost optimization is prioritized |
Compared with TL431BFDT-Q, TL431BMFDT-Q offers identical accuracy but requires mirrored layout; versus TL431AMFDT-Q, it delivers twice the reference precision at modest cost premium - making it optimal for ASIL-B feedback paths where 0.5 % sets the system-level voltage error budget.
Availability
TL431BMFDT-QR is available at Aetrix Electronics and suitable for automotive power conversion, battery monitoring, and precision current regulation requiring stable component supply across extended temperature ranges and AEC-Q100 compliance.
Supply support for TL431BMFDT-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 delivering high-performance, reliable discrete, logic, and MOSFET solutions with focus on efficiency, reliability, and miniaturization for automotive and industrial markets.
The TL431-Q family is engineered for automotive-grade precision voltage regulation, targeting isolated feedback, current limiting, and programmable threshold applications where AEC-Q100 qualification and extended temperature operation are mandatory.
FAQ
What is the pinout configuration of TL431BMFDT-QR?
TL431BMFDT-QR uses mirrored SOT23 pinning: Pin 1 = REF (reference input), Pin 2 = K (cathode), Pin 3 = A (anode). This differs from standard TL431 variants (K–REF–A) and must be accounted for in PCB layout to ensure correct voltage divider connection and current sinking path.
How does the B-grade tolerance affect design margin in automotive applications?
The ±0.5 % B-grade reference voltage (2.483 V to 2.507 V) directly limits total output voltage error in feedback networks. In a 12 V SMPS with 100:1 resistor ratio, this contributes ±0.06 V error - enabling compliance with ISO 16750-2 load-dump and cold-crank specifications without additional trimming.
Can TL431BMFDT-QR replace standard TL431 in existing designs?
Yes, functionally - but only with PCB layout modification to accommodate mirrored pinout (REF–K–A vs. K–REF–A). Electrical characteristics including reference voltage, impedance, and temperature range are identical to other B-grade TL431-Q devices; no schematic changes are needed beyond pin mapping.
What thermal derating applies at 125 °C ambient?
At Tamb = 125 °C, maximum power dissipation drops to 350 mW on standard FR4 PCB (single-sided copper, tin-plated). This corresponds to ~35 mA cathode current at 10 V cathode-anode drop - sufficient for most feedback and bias applications but requires verification against actual operating VKA and IK in thermal simulation.
TL431BMFDT-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:
- ±0.5%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 600 µA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3 (TO-236)
TL431BMFDT-QR FAQ
1.How can I place an order for TL431BMFDT-QR through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431BMFDT-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 TL431BMFDT-QR reliable?
The price and inventory of TL431BMFDT-QR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431BMFDT-QR is usually 5 days.
3.What payment methods are accepted for TL431BMFDT-QR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431BMFDT-QR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431BMFDT-QR?
TL431BMFDT-QR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431BMFDT-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 TL431BMFDT-QR?
For technical support, including TL431BMFDT-QR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431BMFDT-QR requirements.
6.How does Aetrix verify that TL431BMFDT-QR is sourced from the original manufacturer or authorized distributors?
All TL431BMFDT-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 TL431BMFDT-QR meets industry standards.
7.What is the process for return or replacement of TL431BMFDT-QR?
All TL431BMFDT-QR units undergo pre-shipment inspection (PSI). If there is an issue with TL431BMFDT-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 TL431BMFDT-QR part is unused and in its original packaging.
Return procedure for TL431BMFDT-QR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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