Texas Instruments TL431CDBVTG4

Overview

TL431CDBVTG4 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, 0.2 Ω typical dynamic impedance, and 1 mA to 100 mA sink-current capability for feedback regulation in switching power supplies. It operates across 0°C to 70°C and replaces Zener diodes in adjustable voltage control loops.

For engineers reviewing the TL431CDBVTG4 datasheet, TL431CDBVTG4 pinout, TL431CDBVTG4 application, or TL431CDBVTG4 equivalent, this page provides verified electrical specifications, thermal behavior, stability boundaries, real-world use cases in AC/DC converters and servo drives, and validated alternative parts for design flexibility and supply continuity.

Technical Context

The TL431CDBVTG4 implements a three-terminal adjustable shunt regulator architecture with an internal error amplifier, reference, and output transistor. Its sharp turn-on characteristic and low 0.2 Ω dynamic impedance enable stable closed-loop regulation without external compensation in many configurations.

It features a 2.495 V bandgap-based reference with 6 mV max temperature drift over 0°C–70°C (C-grade), 2 µA–4 µA reference input current, and cathode voltage range from V_ref to 36 V - supporting wide-output adjustable supplies via two external resistors.

Key Specifications

Pinout & Package

SOT-23-3 package (2.90 mm × 1.30 mm), surface-mount, tape-and-reel compatible; thermally optimized for power dissipation up to 360 mW at TA = 70°C (R_θJA = 206°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431CDBVTG4, TL431CDBVR offers identical performance with halogen-free packaging, while TLVH431BQDBVR shifts reference voltage and temperature range - making it unsuitable as a direct replacement but viable for new designs needing lower V_ref or extended thermal operation.

Availability

TL431CDBVTG4 is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC converters, and servo drive control modules requiring stable component supply with guaranteed long-term sourcing and full traceability.

Supply support for TL431CDBVTG4 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 solutions.

The TL431 product line delivers cost-effective, high-accuracy shunt references for feedback regulation in switching power supplies, battery chargers, and industrial control systems - designed for reliability, wide temperature operation, and ease of implementation.

FAQ

What is the reference voltage tolerance of TL431CDBVTG4 at 25°C?

The TL431CDBVTG4 has a ±0.5% initial reference voltage tolerance at 25°C, corresponding to a 2.495 V nominal value with ±12.5 mV deviation. This B-grade accuracy is confirmed in Section 6.11 of the TI SLVS543S datasheet and applies specifically to the C-temp (0°C to 70°C) and B-tolerance variant. TL431CDBVTG4 maintains this tolerance without calibration or trimming.

Does TL431CDBVTG4 support operation above 70°C?

No, TL431CDBVTG4 is rated for 0°C to 70°C free-air temperature (C-grade). For operation up to 125°C, TI offers the TL431BQDBVT variant (Q-grade). The TL431CDBVTG4's thermal specifications - including R_θJA = 206°C/W and maximum junction temperature of 150°C - are defined only within its 0°C–70°C ambient range; exceeding this invalidates parametric guarantees.

What is the minimum cathode current required for regulation in TL431CDBVTG4?

The TL431CDBVTG4 requires a minimum cathode current of 0.4 mA to maintain regulation, as specified in Section 6.5 of the datasheet under "Imin". Below this threshold, the device exits active regulation and reference accuracy degrades. This value is consistent across all TL431C variants and is independent of external resistor values once the REF pin voltage reaches 2.495 V.

Can TL431CDBVTG4 replace a Zener diode in linear regulator circuits?

Yes, TL431CDBVTG4 is explicitly designed as a superior Zener diode replacement in shunt regulator topologies. Its 0.2 Ω dynamic impedance, sharp turn-on, and 2.495 V ±0.5% reference provide tighter regulation, lower noise, and better temperature stability than discrete Zeners - especially in feedback paths of switching regulators and precision voltage monitors.

Is TL431CDBVTG4 pin-compatible with TL432 devices?

No, TL431CDBVTG4 is not pin-compatible with TL432 devices in any package. While functionally identical, TL432 uses reversed pinout in SOT-23-3 (Cathode–Ref–Anode vs. TL431's Cathode–Anode–Ref). Using TL432 in place of TL431CDBVTG4 without PCB revision will cause incorrect biasing and failure to regulate. Always verify pin configuration from TI's Pin Configuration and Functions section (Page 4).