Texas Instruments TL431AIDBVT

Overview

TL431AIDBVT from Texas Instruments is a precision programmable shunt voltage reference in SOT-23-3 package, featuring 1% initial reference voltage tolerance at 25°C, adjustable output from 2.495 V to 36 V, and operation across −40°C to 85°C. It delivers 0.2 Ω typical dynamic impedance and supports 1–100 mA sink current, enabling high-accuracy feedback in isolated DC/DC converters and industrial power supplies.

For engineers reviewing the TL431AIDBVT datasheet, TL431AIDBVT pinout, TL431AIDBVT application, or TL431AIDBVT equivalent, key selection criteria include its A-grade accuracy, thermal stability over industrial temperature range, low noise performance, and compatibility with standard resistor-divider programming for flexible output setting.

Technical Context

The TL431AIDBVT implements a three-terminal adjustable shunt regulator architecture with an internal 2.495 V reference, error amplifier, and NPN output stage. Its sharp turn-on characteristic and active output circuitry replace discrete Zener diodes in closed-loop regulation schemes.

It operates as a two-input (REF, ANODE), one-output (CATHODE) device where the REF pin senses voltage relative to ANODE, and CATHODE sinks current proportional to the error between sensed voltage and internal reference - enabling precise voltage regulation without external op-amps.

Key Specifications

Pinout & Package

SOT-23-3 package (2.90 mm × 1.30 mm), surface-mount, tape-and-reel compatible. Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431CDBVR, TL431AIDBVT offers extended temperature capability critical for industrial reliability; compared with TL431BIDBVT, it trades 0.5% accuracy for lower unit cost while retaining full industrial operating range - making it optimal for cost-sensitive, thermally demanding applications.

Availability

TL431AIDBVT is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, and servo drive control modules requiring stable component supply with guaranteed long-term sourcing.

Supply support for TL431AIDBVT 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

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of expertise in precision analog ICs and power management solutions.

The TL431 product line was designed for high-accuracy voltage regulation in isolated and non-isolated power conversion systems, targeting industrial, computing, and automotive applications where stability, low drift, and robustness are mandatory.

FAQ

What is the reference voltage tolerance of TL431AIDBVT at 25°C?

The TL431AIDBVT has a reference voltage tolerance of ±1% at 25°C, corresponding to a nominal 2.495 V output with a guaranteed range of 2.470 V to 2.520 V. This A-grade accuracy is specified in TI's SLVS543S datasheet Section 6.8 and enables predictable feedback threshold setting without post-manufacturing calibration. The TL431AIDBVT maintains this tolerance across its full industrial temperature range.

Can TL431AIDBVT be used in place of a Zener diode?

Yes, TL431AIDBVT replaces Zener diodes in precision regulation applications due to its sharp turn-on characteristic, 0.2 Ω dynamic impedance, and programmable 2.495 V–36 V output. Unlike Zeners, TL431AIDBVT provides stable reference voltage independent of current variation, eliminating knee-voltage uncertainty. Its active output stage also supports higher sink current (up to 100 mA), making TL431AIDBVT ideal for driving optocouplers in isolated SMPS designs.

What is the maximum cathode voltage for TL431AIDBVT?

The absolute maximum cathode voltage (VKA) for TL431AIDBVT is 37 V, with recommended operating range from Vref (≈2.495 V) to 36 V. Exceeding 37 V risks permanent damage per Section 6.1 of the datasheet. In practice, VKA must remain within 36 V during normal operation to ensure reliability and maintain specified electrical characteristics - critical when designing overvoltage protection circuits using TL431AIDBVT.

Does TL431AIDBVT require external capacitors for stability?

TL431AIDBVT may require an external capacitor (typically 1 nF–100 nF) from CATHODE to ANODE in high-gain or high-capacitive-load configurations to prevent oscillation, as shown in Figure 6-16 of the datasheet. Stability depends on load capacitance and cathode current; for IKA < 10 mA and CL < 100 pF, no capacitor is needed. Always verify phase margin in final layout - TL431AIDBVT's internal compensation is optimized for general-purpose use but not universally unconditional.

What package type does TL431AIDBVT use?

TL431AIDBVT uses the SOT-23-3 surface-mount package (2.90 mm × 1.30 mm body size), with pinout: Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE. This compact, tape-and-reel-ready package supports automated assembly and meets JEDEC MO-178 standards. The SOT-23-3 footprint is shared across TL431x variants, enabling drop-in replacement within the same grade and temperature range - confirmed in TI's Device Information table and Package Mechanical Drawings.