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Nexperia USA Inc. TL431AMFDT-QR
- Part No.:
- TL431AMFDT-QR
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TL431AMFDT-QR.pdf
- Description:
- IC VREF SHUNT 2.495V SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:1,121
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Product details
Overview
TL431AMFDT-QR from Nexperia is an A-grade (±1.0 %) adjustable precision shunt regulator in SOT23 package with mirrored pinning (REF–K–A), operating from −40 °C to +125 °C, delivering 2.470 V to 2.520 V reference voltage at 10 mA cathode current, and supporting output voltage programming from 2.495 V to 36 V via two external resistors - used in automotive SMPS feedback loops and precision current sinks.
For engineers reviewing the TL431AMFDT-QR datasheet, TL431AMFDT-QR pinout, TL431AMFDT-QR application, or TL431AMFDT-QR equivalent, this page delivers verified pin mapping, temperature-stable reference performance, automotive-qualified operation, and direct substitution guidance for shunt regulation in isolated power supplies and battery management systems.
Technical Context
The TL431AMFDT-QR implements a three-terminal shunt regulator architecture with an internal bandgap reference, error amplifier, and NPN output stage. Its mirrored pinning (Pin 1 = REF, Pin 2 = K, Pin 3 = A) enables PCB layout compatibility with space-constrained automotive modules requiring reverse footprint orientation.
It operates as a programmable voltage-controlled current sink: when the REF pin voltage exceeds 2.495 V, the cathode-anode path conducts up to 100 mA, maintaining precise regulation across input transients. Dynamic impedance remains ≤0.5 Ω below 1 kHz, enabling stable closed-loop response in feedback networks with ≤100 nF compensation capacitance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage (Vref) | 2470–2520 mV at 10 mA IK, −40 °C to +125 °C - ensures ±1 % accuracy over full automotive temperature range without external trimming. |
| Cathode Current Range | 1–100 mA - supports direct replacement of Zener diodes in low-to-medium power shunt regulation and enables >50 mA precision current sinking. |
| Dynamic Cathode-Anode Impedance | 0.2–0.5 Ω below 1 kHz - provides low-noise, high-stability regulation critical for isolated flyback and forward converter feedback paths. |
| Reference Input Current | 2–4 μA typical - minimizes resistor-divider loading error, allowing use of high-value feedback resistors (>1 MΩ) to reduce quiescent power. |
| Temperature Drift (ΔVref) | ±17–34 mV over −40 °C to +125 °C - guarantees predictable regulation shift in under-hood automotive environments without recalibration. |
| ESD Rating | 4 kV HBM - meets automotive robustness requirements for handling and board-level integration without additional protection circuitry. |
Pinout & Package
SOT23 plastic surface-mounted package (3 leads), 1.9 mm × 1.1 mm × 0.9 mm body, standard footprint per Fig. 28 (reflow) and Fig. 29 (wave soldering); thermal resistance Rth(j-a) = 360 K/W on FR4 PCB.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (REF) | Reference input | High-impedance node sensing external resistor divider; must be decoupled with ≤100 pF to suppress noise injection from primary-side switching. |
| 2 (K) | Cathode | Current-sink output terminal; connects to SMPS optocoupler anode or series-pass transistor base; handles up to 100 mA continuous sink current. |
| 3 (A) | Anode | Return path to system ground or negative rail; forms low-impedance cathode-anode loop essential for dynamic stability and transient response. |
Key Features
| Feature | Design Value |
|---|---|
| Programmable output voltage | 2.495 V to 36 V using only two external resistors - eliminates need for multiple fixed-voltage regulators in multi-rail automotive ECUs. |
| A-grade reference tolerance | ±1.0 % over −40 °C to +125 °C - enables single-bill-of-materials design across commercial and automotive platforms without derating. |
| Low dynamic impedance | 0.2 Ω typical - maintains tight output regulation during load steps in battery-powered instrumentation and sensor supply rails. |
| Automotive qualification | AEC-Q100 Grade 1 qualified - certified for under-hood deployment in ADAS camera modules, body control units, and infotainment power stages. |
| Mirrored pinning (MFDT) | REF–K–A sequence (vs. standard K–REF–A) - allows optimized PCB routing in dense layouts where cathode trace length must be minimized for EMI reduction. |
Applications
| Automotive SMPS Feedback | Precision Current Sink |
|---|---|
|
Use Scenario: Isolated DC-DC converter in electric power steering (EPS) control module, using optocoupler-coupled secondary-side regulation. IC Role / Device Role / Timing Role: Shunt regulator providing error signal to optocoupler LED; sets regulated output voltage via resistor divider on secondary side. Use Value: Enables ±1 % output accuracy over −40 °C to +125 °C ambient, reducing need for post-production calibration and improving system efficiency at light loads. |
Use Scenario: Constant-current source for automotive LED headlamp driver with thermal foldback. IC Role / Device Role / Timing Role: Precision current sink controlling gate voltage of external MOSFET; reference voltage defines current setpoint via sense resistor. Use Value: Delivers stable 200 mA ±1.5 % across temperature, eliminating drift-induced brightness variation and extending LED lifetime. |
| Battery Cell Monitor Reference | Industrial Sensor Excitation |
|
Use Scenario: High-side voltage reference in 12-cell Li-ion battery pack monitor IC for cell balancing control logic. IC Role / Device Role / Timing Role: Programmable shunt reference generating stable 2.5 V for ADC reference and comparator thresholds in analog front-end. Use Value: Maintains <±2 mV drift over full temperature range, ensuring accurate cell voltage measurement and preventing false overvoltage trips. |
Use Scenario: Excitation source for 4-wire RTD bridge in industrial process transmitter operating in hazardous locations. IC Role / Device Role / Timing Role: Low-noise, low-drift voltage reference driving precision current source for RTD biasing. Use Value: Reduces total system error to <0.1 % FS by minimizing reference contribution to gain and offset drift in 24-bit sigma-delta measurements. |
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 | Same A-grade tolerance and temperature range, but standard pinning (K–REF–A). | Requires PCB layout revision to accommodate cathode-first orientation; no change in feedback network design. | Select when existing layout uses standard SOT23 pinout and mechanical clearance permits cathode trace routing. |
| TL431BMFDT-Q | B-grade (±0.5 %) tolerance, identical mirrored pinning and thermal rating. | Delivers tighter reference accuracy but increases cost; no change in thermal or electrical interface. | Select for applications requiring <±0.5 mV reference stability, such as high-resolution data acquisition front-ends or metrology-grade power supplies. |
Compared with TL431AFDT-Q, TL431AMFDT-QR offers identical accuracy and thermal performance in a reversed footprint that reduces parasitic inductance in high-frequency SMPS feedback paths; versus TL431BMFDT-Q, it trades 0.5 % tolerance for lower unit cost while retaining full automotive qualification and functional compatibility.
Availability
TL431AMFDT-QR is available at Aetrix Electronics and suitable for automotive power conversion, precision current control, and industrial sensor excitation requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TL431AMFDT-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 discrete and analog components, serving automotive, industrial, and consumer markets with AEC-Q100-qualified products.
TL431AMFDT-QR belongs to the TL431-Q family of adjustable precision shunt regulators designed specifically for automotive-grade feedback control, offering guaranteed performance across −40 °C to +125 °C with mirrored pinning for layout flexibility.
FAQ
What is the pin configuration of TL431AMFDT-QR?
TL431AMFDT-QR uses mirrored SOT23 pinning: Pin 1 = REF (reference input), Pin 2 = K (cathode), Pin 3 = A (anode). This differs from standard TL431 variants (e.g., TL431AFDT-Q), which use Pin 1 = K, Pin 2 = REF, Pin 3 = A. The mirrored layout reduces cathode trace inductance in high-frequency SMPS designs.
How does TL431AMFDT-QR achieve ±1 % reference accuracy over temperature?
TL431AMFDT-QR achieves ±1 % Vref accuracy (2470–2520 mV) from −40 °C to +125 °C through laser-trimmed bandgap reference circuitry and matched transistor pairs in its monolithic die. Its A-grade binning is verified per AEC-Q100 stress testing, including temperature cycling and HTOL, ensuring parametric stability across automotive life cycles.
Can TL431AMFDT-QR replace a Zener diode in a 24 V power rail?
Yes - TL431AMFDT-QR replaces Zener diodes in 24 V rails by configuring external resistors to set Vref = 24 V (e.g., R1 = 10 kΩ, R2 ≈ 86.6 kΩ). Its 0.2 Ω dynamic impedance and 100 mA sink capability provide superior regulation, lower noise, and sharper turn-on than typical 24 V Zeners, especially under varying load or temperature conditions.
Is TL431AMFDT-QR compatible with optocoupler-based feedback in flyback converters?
Yes - TL431AMFDT-QR is widely used in optocoupler-coupled flyback feedback loops. Its REF pin connects to the voltage divider on the secondary side; cathode drives the optocoupler LED anode. The 2–4 μA reference current minimizes divider loading, and its low output impedance ensures fast response to output voltage deviations without oscillation.
TL431AMFDT-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:
- ±1%
- 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)
TL431AMFDT-QR FAQ
1.How can I place an order for TL431AMFDT-QR through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431AMFDT-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 TL431AMFDT-QR reliable?
The price and inventory of TL431AMFDT-QR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431AMFDT-QR is usually 5 days.
3.What payment methods are accepted for TL431AMFDT-QR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431AMFDT-QR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431AMFDT-QR?
TL431AMFDT-QR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431AMFDT-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 TL431AMFDT-QR?
For technical support, including TL431AMFDT-QR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431AMFDT-QR requirements.
6.How does Aetrix verify that TL431AMFDT-QR is sourced from the original manufacturer or authorized distributors?
All TL431AMFDT-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 TL431AMFDT-QR meets industry standards.
7.What is the process for return or replacement of TL431AMFDT-QR?
All TL431AMFDT-QR units undergo pre-shipment inspection (PSI). If there is an issue with TL431AMFDT-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 TL431AMFDT-QR part is unused and in its original packaging.
Return procedure for TL431AMFDT-QR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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