Nexperia USA Inc. TL431BMFDT/8VL

Overview

TL431BMFDT from Nexperia is a B-grade (0.5 % reference voltage tolerance), adjustable precision shunt regulator in SOT23 package with mirrored pinning (REF–K–A), operating across –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 from 2.495 V to 36 V via two external resistors - widely deployed in isolated SMPS feedback loops.

For engineers reviewing the TL431BMFDT datasheet, TL431BMFDT pinout, TL431BMFDT application, or TL431BMFDT equivalent, key selection criteria include its 0.5 % Vref tolerance, mirrored SOT23 pinout, 0.2 Ω dynamic impedance, 1 mA to 100 mA sink capability, and –40 °C to 125 °C extended temperature range for industrial power regulation.

Technical Context

The TL431BMFDT implements a three-terminal shunt regulator architecture with an internal bandgap reference, error amplifier, and NPN output stage. 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 functional failure.

It operates as a programmable voltage-controlled current sink: when the REF pin voltage exceeds 2.495 V, the cathode-anode path conducts, sinking up to 100 mA. Its 0.2 Ω typical dynamic impedance and <9 mV temperature drift over 0 °C to 70 °C ensure stable regulation under load and thermal variation.

Key Specifications

Pinout & Package

SOT23 plastic surface-mounted package (3 leads), 1.9 mm × 1.1 mm footprint, 0.95 mm height; mirrored pinning configuration specific to MFDT-suffixed variants.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar shunt regulator applications.

Compared with TL431BFDT, TL431BMFDT offers identical electrical performance but mandates mirrored layout; versus TL431ACDBZR, it delivers double the accuracy and triple the temperature range - critical for industrial power integrity.

Availability

TL431BMFDT is available at Aetrix Electronics and suitable for isolated SMPS feedback design, precision current sink circuits, and programmable shunt regulation requiring stable component supply across extended temperature environments.

Supply support for TL431BMFDT 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 specializing in high-performance, reliable discrete, logic, and MOSFET solutions, with manufacturing rooted in process innovation and automotive-grade quality systems.

TL431BMFDT belongs to Nexperia's precision shunt regulator family, engineered for high-accuracy voltage reference and current regulation in industrial power conversion, automotive subsystems, and embedded control applications.

FAQ

What is the pinout configuration of TL431BMFDT?

TL431BMFDT 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 requires a dedicated PCB footprint. Incorrect routing will prevent regulation or cause device malfunction.

How does TL431BMFDT achieve 0.5 % reference voltage accuracy?

The 0.5 % tolerance (2483–2507 mV at 10 mA, 25 °C) is achieved through laser-trimmed bandgap reference circuitry and post-package testing screening. It is maintained across –40 °C to +125 °C with ΔVref ≤ ±34 mV, enabling high-precision closed-loop control without external calibration.

Can TL431BMFDT replace a Zener diode in existing designs?

Yes - TL431BMFDT replaces Zener diodes in shunt regulation roles with superior performance: adjustable output (2.495–36 V), 0.2 Ω dynamic impedance vs. Zener's >10 Ω, and sharp turn-on. However, its 3-pin topology and REF pin sensitivity require adding two resistors and guarding against noise coupling.

What is the maximum power dissipation for TL431BMFDT on a standard FR4 PCB?

On a standard FR4 PCB (single-sided copper, tin-plated, standard footprint), TL431BMFDT has a maximum power dissipation of 350 mW at Tamb ≤ 25 °C. Power derates linearly above 25 °C per Figure 2, reaching 0 mW at ~125 °C ambient - consistent with its –40 °C to +125 °C operational rating.