STMicroelectronics TS3431AILT

Overview

TS3431AILT from STMicroelectronics is an adjustable precision shunt voltage reference IC in SOT23-3L package, functioning as a 1.24–24 V programmable voltage reference with ±1% initial accuracy at 25 °C, 100 ppm/°C temperature coefficient, and 0.4–100 mA sink current capability. It replaces TL431 in space-constrained industrial power supplies and battery charger feedback loops.

For engineers reviewing the TS3431AILT datasheet, TS3431AILT pinout, TS3431AILT application, or TS3431AILT equivalent, key selection criteria include guaranteed -40 °C to +105 °C operation, low 2.0 µA reference input current, 0.4 Ω dynamic impedance, 100 nV/√Hz wideband noise, and compatibility with standard TL431 PCB layouts.

Technical Context

The TS3431AILT implements a two-terminal shunt regulator architecture with internal bandgap reference, error amplifier, and NPN output stage. Its cathode-anode configuration enables direct feedback control in isolated DC-DC converters and linear regulators without external biasing.

It operates over full industrial temperature range (-40 °C to +105 °C) with guaranteed 18 mV reference voltage drift and maintains stable regulation down to 0.5 mA minimum cathode current across temperature. The device achieves 100 ppm/°C TC via curvature-compensated bandgap design and laser-trimmed resistive network.

Key Specifications

Pinout & Package

SOT23-3L plastic micropackage (3-pin surface-mount), 1.12 mm height, 2.90 mm × 1.30 mm footprint, JEDEC TO-236AB compliant, thermally enhanced for 360 mW dissipation at 25 °C ambient.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431ACDT and MAX6008AEUR+T, the TS3431AILT uniquely balances ±1% accuracy, 0.4 Ω impedance, and 1.24–24 V adjustability in SOT23-3L-making it optimal for compact, wide-temperature, multi-rail industrial power designs.

Availability

TS3431AILT is available at Aetrix Electronics and suitable for computer power supplies, industrial battery chargers, and switch mode power supplies requiring stable component supply with guaranteed long-term availability and consistent parametric performance.

Supply support for TS3431AILT 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power management ICs, sensors, and analog components for industrial, automotive, and consumer markets.

The TS3431 series belongs to ST's precision analog portfolio, engineered specifically for high-reliability shunt reference applications demanding tight initial tolerance, low temperature drift, and robust operation in harsh thermal environments.

FAQ

What is the minimum cathode current required for regulation at -40 °C?

The TS3431AILT requires a minimum cathode current of 0.5 mA across the full -40 °C to +105 °C operating range, as specified in Table 2 of DS3673 Rev 7. This value is guaranteed by design correlation and production testing, ensuring reliable turn-on and regulation even at extreme cold temperatures.

Can TS3431AILT replace TL431 in existing designs without layout changes?

Yes-TS3431AILT uses identical SOT23-3L pinout (Anode-Cathode-Reference) and matches TL431's electrical interface, including compatible cathode voltage range (1.24–24 V) and sink current capability. No PCB modification is needed, though resistor values may require minor adjustment to match ±1% tolerance.

What is the maximum power dissipation in SOT23-3L at 85 °C ambient?

At 85 °C ambient, the TS3431AILT's maximum power dissipation is derated to approximately 220 mW, calculated using R_thja = 340 °C/W from DS3673 Rev 7 Table 1. This assumes T_j ≤ 150 °C and accounts for thermal resistance between junction and ambient air in standard PCB mounting conditions.

Does TS3431AILT support operation above 24 V cathode-to-anode voltage?

No-the absolute maximum cathode-to-anode voltage (V_KA) is 25 V per Table 1, and the functional operating range is limited to 1.24–24 V. Exceeding 24 V violates the specified operating conditions and risks instability or accelerated degradation, even if within absolute maximum ratings.