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Nexperia USA Inc. TL431BMFDT/8R
- Part No.:
- TL431BMFDT/8R
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TL431BMFDT/8R.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% TO236AB
- Quantity:
- Payment:
- Shipping:
Inventory:3,886
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Product details
Overview
TL431BMFDT/8R from Nexperia is a B-grade (±0.5 %) adjustable precision shunt regulator in SOT23 package with mirrored pinning (REF–K–A), operating from −40 °C to +125 °C, delivering 2.483 V to 2.507 V reference voltage at 10 mA cathode current, and supporting output voltage programming up to 36 V via two external resistors - used in isolated SMPS feedback loops, precision current sinks, and voltage monitoring circuits.
For engineers reviewing the TL431BMFDT/8R datasheet, TL431BMFDT/8R pinout, TL431BMFDT/8R application, or TL431BMFDT/8R equivalent, key selection criteria include its 0.5 % reference tolerance, 0.2 Ω dynamic impedance, 100 mA sink capability, −40 °C to +125 °C extended temperature range, and SOT23 mirrored pin configuration for PCB layout compatibility in high-reliability power control designs.
Technical Context
The TL431BMFDT/8R implements a precision bandgap-based reference amplifier driving an NPN output stage, enabling sharp turn-on and stable regulation across wide cathode-anode voltage (2.495 V to 36 V) and load current (1 mA to 100 mA) ranges. Its internal architecture supports low-noise operation and minimal thermal drift (±17 mV over −40 °C to +125 °C).
Unlike fixed-voltage shunt regulators, it requires only two external resistors to set output voltage, and its mirrored pinout (Pin 1 = REF, Pin 2 = K, Pin 3 = A) distinguishes it from standard-pin variants - critical for correct PCB footprint placement and avoiding reverse-bias misconnection in feedback networks.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference voltage (Vref) | 2483–2507 mV at 10 mA, IK = 10 mA, Tamb = 25 °C - defines accuracy baseline for programmable output setting |
| Cathode-anode voltage (VK-A) | 2.495 V to 36 V - sets maximum programmable output range using external resistor divider |
| Cathode current (IK) | 1 mA to 100 mA - determines minimum load/sink capability and power dissipation headroom |
| Dynamic impedance (ZK-A) | 0.2 Ω typical, f < 1 kHz - ensures tight regulation under transient load changes in feedback paths |
| Reference current (Iref) | 2–4 μA - defines bias current drawn from REF node, critical for high-impedance resistor divider design |
| Temperature range | −40 °C to +125 °C - enables use in automotive engine control, industrial power supplies, and outdoor equipment |
| Output noise | Low - supports stable regulation in sensitive analog feedback loops without added filtering |
Pinout & Package
SOT23 plastic surface-mounted package (3 leads), 1.9 mm × 1.3 mm footprint, 0.95 mm height, with mirrored pinning configuration specific to MFDT-suffixed variants.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | REF | Reference input node - connects to center tap of external resistor divider; draws 2–4 μA bias current |
| Pin 2 | K (Cathode) | Current sink terminal - carries regulated output current up to 100 mA; connects to supply rail in shunt configuration |
| Pin 3 | A (Anode) | Return path - ties to system ground or low-side return; completes regulation loop with REF and K |
Key Features
| Feature | Design Value |
|---|---|
| 0.5 % reference voltage tolerance | B-grade accuracy enables ±0.5 % output voltage setting in closed-loop SMPS without trimming |
| Extended temperature range | −40 °C to +125 °C operation supports under-hood automotive and industrial ambient conditions |
| 0.2 Ω dynamic impedance | Minimizes output voltage deviation during fast load transients in feedback control applications |
| Mirrored SOT23 pinout | Prevents PCB layout conflict with standard-pin TL431 variants when migrating designs or sharing footprints |
| Low reference current | 2–4 μA Iref allows high-value resistor dividers (>1 MΩ), reducing power loss in battery-powered systems |
Applications
| Isolated SMPS Feedback | Precision Current Sink |
|---|---|
|
Use Scenario: Secondary-side voltage sensing in flyback or forward converters with optocoupler-coupled feedback. IC Role / Device Role / Timing Role: Shunt regulator providing precise reference to drive optocoupler LED, closing voltage regulation loop across isolation barrier. Use Value: Enables ±0.5 % output voltage stability despite primary-side component tolerances and transformer leakage. |
Use Scenario: Constant-current biasing of laser diodes or LED strings in instrumentation lighting. IC Role / Device Role / Timing Role: Adjustable shunt element sinking current through load-resistor network to maintain fixed current independent of supply variation. Use Value: Delivers 1 % current accuracy over temperature using only two resistors and no op-amp compensation. |
| Voltage Monitor with Hysteresis | Programmable Threshold Detector |
|
Use Scenario: Overvoltage protection circuit triggering shutdown when input exceeds 24 V in 24 V industrial rail. IC Role / Device Role / Timing Role: Precision shunt reference combined with comparator hysteresis network to define accurate trip point. Use Value: Achieves 24.0 V ±0.12 V threshold accuracy without calibration, leveraging 0.5 % Vref and stable ZK-A. |
Use Scenario: Single-supply comparator with temperature-stable switching threshold in battery management ICs. IC Role / Device Role / Timing Role: Reference generator feeding non-inverting input of comparator; REF pin sets exact trip voltage via resistor ratio. Use Value: Eliminates need for external voltage reference IC, reducing BOM count while maintaining <±10 mV threshold drift from −40 °C to +125 °C. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BFDT | Same B-grade tolerance and temperature range, but standard pinning (K–REF–A) | Requires PCB footprint revision; unsuitable for drop-in replacement where mirrored layout is fixed | Select when redesigning layout to match industry-standard TL431 pinout and optimizing for sourcing flexibility |
| TL431ACDBZR | A-grade (±1.0 %) tolerance, 0 °C to +70 °C commercial temp range, standard pinning | Limited to non-automotive, indoor consumer/industrial applications; lower accuracy than TL431BMFDT/8R | Choose for cost-sensitive, non-extended-temp designs where ±1 % output regulation suffices |
Compared with TL431BFDT, TL431BMFDT/8R offers identical electrical performance but mandates mirrored PCB layout; compared with TL431ACDBZR, it trades wider temperature coverage and tighter tolerance for higher unit cost and stricter layout constraints.
Availability
TL431BMFDT/8R is available at Aetrix Electronics and suitable for isolated SMPS feedback, precision current sink, and voltage monitor applications requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.
Supply support for TL431BMFDT/8R 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, discrete, and MOSFET solutions, headquartered in Nijmegen, Netherlands.
The TL431 family belongs to Nexperia's precision analog portfolio, designed specifically for voltage regulation, current limiting, and feedback control in power conversion and protection circuits across automotive, industrial, and computing markets.
FAQ
What is the pin configuration of TL431BMFDT/8R?
TL431BMFDT/8R uses mirrored SOT23 pinning: Pin 1 = REF, Pin 2 = K (cathode), Pin 3 = A (anode). This differs from standard TL431 variants (K–REF–A) and must be verified against PCB footprint before assembly to prevent functional failure.
Does TL431BMFDT/8R support automotive qualification?
No - per Nexperia's Rev. 8 datasheet (2025), TL431BMFDT/8R was removed from AEC-Q100 qualification in the September 2024 revision update and is not approved for automotive applications. It remains rated for −40 °C to +125 °C operation but lacks automotive stress-test validation.
How do I calculate the output voltage using external resistors?
Use VOUT = Vref × (1 + R1/R2), where R1 connects between cathode and output, R2 connects between REF and ground. For TL431BMFDT/8R, Vref = 2.495 V nominal; select R1/R2 ratio to achieve target VOUT, ensuring Iref ≤ 4 μA and minimum cathode current ≥ 0.4 mA.
Can TL431BMFDT/8R replace a Zener diode directly?
Yes - as a 3-terminal active Zener substitute, it provides superior voltage accuracy, lower dynamic impedance (0.2 Ω vs. >10 Ω for typical Zeners), and programmable output. However, it requires external biasing (REF node connection) and cannot be used as a 2-terminal drop-in; circuit redesign is mandatory.
TL431BMFDT/8R 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:
- Obsolete
- 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:
- TO-236AB
TL431BMFDT/8R FAQ
1.How can I place an order for TL431BMFDT/8R through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431BMFDT/8R 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/8R reliable?
The price and inventory of TL431BMFDT/8R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431BMFDT/8R is usually 5 days.
3.What payment methods are accepted for TL431BMFDT/8R?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431BMFDT/8R transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431BMFDT/8R?
TL431BMFDT/8R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431BMFDT/8R 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/8R?
For technical support, including TL431BMFDT/8R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431BMFDT/8R requirements.
6.How does Aetrix verify that TL431BMFDT/8R is sourced from the original manufacturer or authorized distributors?
All TL431BMFDT/8R 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/8R meets industry standards.
7.What is the process for return or replacement of TL431BMFDT/8R?
All TL431BMFDT/8R units undergo pre-shipment inspection (PSI). If there is an issue with TL431BMFDT/8R, 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/8R part is unused and in its original packaging.
Return procedure for TL431BMFDT/8R:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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