Texas Instruments TL431IDBVT

Overview

TL431IDBVT 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 temperature drift over −40°C to 85°C, 0.2 Ω typical dynamic impedance, and 1–100 mA sink-current capability. It serves as a stable feedback element in isolated DC/DC converters and AC/DC power supplies.

For engineers reviewing the TL431IDBVT datasheet, TL431IDBVT pinout, TL431IDBVT application, or TL431IDBVT equivalent, key selection criteria include its guaranteed 0.5% reference accuracy at 25°C, operation across industrial temperature range (−40°C to 85°C), low output noise, sharp turn-on characteristic for Zener replacement, and compatibility with standard resistor-divider programming from 2.5 V to 36 V.

Technical Context

The TL431IDBVT implements an internal error amplifier with high-gain transconductance stage driving a NPN pass transistor, enabling precise regulation via external resistive feedback between cathode and reference pins. Its architecture supports both shunt-mode regulation and active current-sinking configurations without requiring external compensation in most applications.

It features a dedicated REF input pin referenced to ANODE (not ground), allowing floating operation in high-side sensing topologies. The device's 0.2 Ω dynamic impedance and <1 µA reference input current minimize loading effects on feedback networks, while its 14 mV total drift over −40°C to 85°C ensures stability in industrial power control loops.

Key Specifications

Pinout & Package

SOT-23-3 package (2.90 mm × 1.30 mm body size) with gull-wing leads; RoHS-compliant, lead-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431CDBVR and TLVH431ILP, TL431IDBVT uniquely combines B-grade accuracy, industrial temperature qualification, and direct SOT-23-3 pin compatibility-making it the optimal choice for cost-sensitive yet performance-critical industrial power designs where calibration overhead and thermal margin are constrained.

Availability

TL431IDBVT is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, and servo drive control modules requiring stable component supply with consistent parametric performance across production batches.

Supply support for TL431IDBVT 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 technologies with over 50 years of innovation in precision analog ICs.

The TL431 product line was designed specifically for high-accuracy, low-drift shunt voltage regulation in isolated power supplies, feedback loops, and voltage monitoring circuits-targeting industrial, telecom, and computing applications demanding long-term stability.

FAQ

What is the reference voltage tolerance of TL431IDBVT at 25°C?

The TL431IDBVT has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 2.495 V nominal value with a min/max range of 2.483 V to 2.507 V. This B-grade accuracy is specified in TI's SLVS543S datasheet Section 6.11 and is validated across production lots. TL431IDBVT maintains this tolerance without requiring external calibration, making it suitable for precision power supply feedback paths where tight output regulation is required.

Does TL431IDBVT support operation beyond 85°C?

No, TL431IDBVT is rated for operation from −40°C to +85°C (I-grade), as confirmed in Section 4 (Device Comparison Table) and Section 6.4 (Recommended Operating Conditions) of the TI datasheet. For extended temperature operation up to 125°C, the Q-grade variant TL431BQDBVR must be used instead. Using TL431IDBVT above 85°C may result in increased reference drift beyond the 14 mV specification and potential reliability degradation.

Can TL431IDBVT replace a Zener diode directly in existing designs?

Yes, TL431IDBVT can directly replace Zener diodes in most shunt-regulator applications due to its sharp turn-on characteristic, low dynamic impedance (0.2 Ω), and programmable output (2.5 V to 36 V). Unlike Zeners, TL431IDBVT uses a three-terminal configuration (CATHODE, ANODE, REF) and requires no minimum current for regulation beyond 0.4 mA. Its 2–4 µA reference input current also eliminates Zener leakage concerns in high-impedance feedback networks.

What is the maximum cathode voltage rating for TL431IDBVT?

The absolute maximum cathode voltage (VKA) for TL431IDBVT is 37 V, with recommended operation up to 36 V per Section 6.1 and 6.4 of the TI datasheet. Exceeding 36 V risks violating recommended operating conditions and may accelerate parametric shift over time. The 36 V limit applies regardless of sink current level and is referenced to the ANODE pin-not ground-so proper grounding of ANODE is essential for correct voltage interpretation.

Is TL431IDBVT pin-compatible with TL432 variants?

No, TL431IDBVT is not pin-compatible with TL432 devices-even those in SOT-23-3 packages-as explicitly stated in Section 3 of the TI datasheet: "The TL432 device has exactly the same functionality and electrical specifications as the TL431 device, but has different pinouts for the DBV, DBZ, and PK packages." TL431IDBVT uses Cathode–Anode–Ref pinout (1–2–3), whereas TL432DBZ uses Cathode–Ref–Anode (1–2–3). Swapping them will cause functional failure.