Texas Instruments TL431ACDBVRG4

Overview

TL431ACDBVRG4 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 at 25°C, 1 mA–100 mA sink-current capability, and operation across −40°C to 85°C. It replaces Zener diodes in feedback loops of isolated DC/DC converters, AC/DC adapters, and industrial power supplies.

For engineers reviewing the TL431ACDBVRG4 datasheet, TL431ACDBVRG4 pinout, TL431ACDBVRG4 application, or TL431ACDBVRG4 equivalent, key selection criteria include reference accuracy grade (A = 1%), temperature range (I-grade), dynamic impedance (0.2 Ω), cathode voltage range (2.5 V to 36 V), and SOT-23-3 thermal performance (R_θJA = 206°C/W).

Technical Context

The TL431ACDBVRG4 implements an internal bandgap reference and high-gain transconductance amplifier driving an NPN output stage, enabling sharp turn-on and stable regulation via external resistor divider. Its three-terminal architecture (CATHODE, ANODE, REF) supports adjustable output from V_ref to 36 V with minimal external components.

Designed for closed-loop feedback in switching regulators, it features low 0.2 Ω dynamic impedance, 6 mV typical reference drift over 0°C–70°C (C-grade), and 14 mV over −40°C–85°C (I-grade). The SOT-23-3 package supports compact PCB layouts while maintaining thermal stability under 100 mA sink load.

Key Specifications

Pinout & Package

SOT-23-3 package (2.90 mm × 1.30 mm body size) with gull-wing leads; optimized for automated placement and thermal dissipation in high-density power designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431AIDBVR and TLVH431ACDBVR, the TL431ACDBVRG4 provides the best balance of cost, industrial temperature coverage (−40°C to +85°C), and 36 V cathode voltage headroom for mainstream AC/DC and DC/DC designs.

Availability

TL431ACDBVRG4 is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, and notebook PC adapter designs requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for TL431ACDBVRG4 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, embedded processing, and power management ICs, with decades of expertise in precision reference and power control technologies.

The TL431 product line delivers programmable shunt references for feedback regulation in isolated power supplies, designed to replace discrete Zener diodes with superior accuracy, stability, and integration across commercial, industrial, and automotive applications.

FAQ

What is the reference voltage tolerance of TL431ACDBVRG4 at 25°C?

The TL431ACDBVRG4 has a reference voltage tolerance of ±1% at 25°C, corresponding to a nominal 2.495 V output ranging from 2.470 V to 2.520 V. This A-grade specification is confirmed in Section 6.8 of the TI SLVS543S datasheet and applies specifically to the TL431ACDBVRG4 variant in SOT-23-3 packaging.

Does TL431ACDBVRG4 support operation at −40°C?

Yes, TL431ACDBVRG4 is rated for operation from −40°C to +85°C (I-grade temperature range). Its reference voltage deviation remains within 14 mV over this full range, and electrical characteristics including sink current and dynamic impedance are guaranteed per Section 6.9 of the official TI datasheet.

What is the maximum cathode voltage rating for TL431ACDBVRG4?

The absolute maximum cathode voltage for TL431ACDBVRG4 is 37 V, with recommended operating range up to 36 V. This allows safe use in high-input-voltage isolated topologies such as telecom 48 V systems or industrial 36 V bus applications, as specified in Section 6.1 of the TI SLVS543S datasheet.

Can TL431ACDBVRG4 replace a standard Zener diode in feedback circuits?

Yes, TL431ACDBVRG4 is explicitly designed as a precision replacement for Zener diodes in feedback networks. Its sharp turn-on, low 0.2 Ω dynamic impedance, and adjustable 2.5 V–36 V output provide superior regulation accuracy and stability compared to discrete Zeners, especially in switching power supplies.

What package type does TL431ACDBVRG4 use?

TL431ACDBVRG4 uses the SOT-23-3 surface-mount package (body size 2.90 mm × 1.30 mm), with pinout: Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE. This is confirmed in Table 5-1 and the Device Information section of the TI SLVS543S datasheet.