Texas Instruments TL431IDBVTG4

Overview

TL431IDBVTG4 from Texas Instruments is a precision programmable shunt voltage reference in SOT-23-3 package, delivering 2.495 V nominal reference voltage with ±0.5% initial tolerance (B-grade), 14 mV max full-range temperature drift (−40°C to 85°C), and 0.2 Ω typical dynamic impedance - used for secondary-side regulation in isolated flyback SMPSs, adjustable linear regulators, and Zener diode replacement in power supply feedback loops.

For engineers reviewing the TL431IDBVTG4 datasheet, TL431IDBVTG4 pinout, TL431IDBVTG4 application, or TL431IDBVTG4 equivalent, key selection criteria include cathode voltage range (2.5 V to 36 V), sink-current capability (1–100 mA), thermal stability over industrial temperature range, and compatibility with two-resistor external programming for precise output voltage setting.

Technical Context

The TL431IDBVTG4 implements an internal op-amp-based error amplifier with sharp turn-on characteristic and active output circuitry, enabling stable closed-loop regulation without external compensation in many configurations. Its three-terminal shunt architecture places REF as high-impedance input, ANODE as common return, and CATHODE as current-sinking output node.

It operates across −40°C to +85°C (I-grade), supports cathode-to-anode voltage up to 36 V, and maintains regulation down to 0.4 mA minimum cathode current. The device exhibits low output noise and 2–4 µA reference input current, minimizing resistor-divider loading errors in precision feedback networks.

Key Specifications

Pinout & Package

SOT-23-3 package (2.90 mm × 1.30 mm body), surface-mount, lead-free and RoHS-compliant. 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 TL431ACDBVR and TLVH431IDBVR, TL431IDBVTG4 offers the highest initial accuracy (±0.5%) and widest cathode voltage range (up to 36 V), making it optimal for precision isolated power supplies requiring robustness across industrial temperatures.

Availability

TL431IDBVTG4 is available at Aetrix Electronics and suitable for isolated flyback SMPSs, adjustable linear regulators, Zener diode replacements, and voltage monitoring circuits requiring stable component supply with guaranteed long-term sourcing.

Supply support for TL431IDBVTG4 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 company specializing in analog, embedded processing, and power management technologies, with decades of leadership in precision reference design.

The TL431 product line was engineered for high-accuracy, low-drift shunt regulation in power supply feedback paths - targeting cost-sensitive yet performance-critical applications across industrial, computing, and communications markets.

FAQ

What is the reference voltage tolerance of TL431IDBVTG4 at 25°C?

The TL431IDBVTG4 has a ±0.5% initial reference voltage tolerance at 25°C, corresponding to the B-grade specification. This means its Vref falls between 2.483 V and 2.507 V under standard test conditions (VKA = Vref, IKA = 10 mA), enabling high-accuracy feedback in regulated power supplies without post-production trimming. TL431IDBVTG4 achieves this tighter tolerance versus A-grade (±1%) or standard-grade (±2%) variants.

Does TL431IDBVTG4 support operation across the full industrial temperature range?

Yes, TL431IDBVTG4 is rated for operation from −40°C to +85°C (I-grade). Its maximum full-range reference voltage deviation (VI(dev)) is 14 mV over this interval, ensuring stable regulation in demanding environments such as factory automation controllers or outdoor telecom equipment. This specification is confirmed in the TL431I family electrical characteristics tables of the official TI datasheet SLVS543P.

What is the minimum cathode current required for TL431IDBVTG4 to maintain regulation?

The TL431IDBVTG4 requires a minimum cathode current (Imin) of 0.4 mA to sustain regulation, per TI's recommended operating conditions. This low startup current allows reliable operation even with high-value feedback resistors or under ultra-light-load conditions in standby modes. Below this threshold, the device may exit regulation and exhibit unpredictable output behavior - a critical design constraint for low-power flyback or supervisory circuits.

Can TL431IDBVTG4 replace a standard Zener diode in existing designs?

Yes, TL431IDBVTG4 can directly replace Zener diodes in most shunt-regulation applications, offering superior performance: ±0.5% initial tolerance vs. typical ±5% Zener tolerance, 14 mV max temp drift vs. 50–100 mV for Zeners, and 0.2 Ω dynamic impedance vs. 10–100 Ω for Zeners. Its three-terminal SOT-23-3 layout matches common Zener footprints, and REF/ANODE/CATHODE pinout simplifies integration into existing feedback networks without PCB redesign.

What is the maximum cathode-to-anode voltage rating for TL431IDBVTG4?

The absolute maximum cathode-to-anode voltage (VKA) for TL431IDBVTG4 is 37 V, with recommended operation up to 36 V. Exceeding this limit risks permanent damage. This wide voltage range supports use in 24 V industrial systems, 36 V battery chargers, and high-voltage flyback outputs - significantly broader than alternatives like TLVH431 (max 6 V). Designers must ensure VA ≤ VK − 36 V in all operating conditions.