STMicroelectronics TS3431CILT

Overview

TS3431CILT from STMicroelectronics is a precision adjustable shunt voltage reference IC in SOT23-3L package, designed for feedback regulation in power supplies and voltage monitoring circuits. It delivers 1.24 V nominal reference voltage with ±0.25% initial accuracy at 25 °C, supports 0.4–100 mA sink current, operates from –40 °C to +105 °C, and maintains stable output across 1.24–24 V via external resistor divider - widely used in battery chargers and SMPS feedback loops.

For engineers reviewing the TS3431CILT datasheet, TS3431CILT pinout, TS3431CILT application, or TS3431CILT equivalent, this page provides verified electrical specifications, thermal performance data, SOT23-3L terminal mapping, real-world use cases in battery-powered instrumentation, and validated alternative parts with documented tolerance and temperature coefficient differences.

Technical Context

The TS3431CILT implements a two-terminal shunt topology with internal bandgap reference and error amplifier, configured as a programmable cathode-controlled voltage regulator. Its reference input (pin 2) senses voltage across an external resistor network, while cathode (pin 1) sinks current to maintain precise V_REF at the anode (pin 3) node.

It features low dynamic impedance (0.2–0.4 Ω), wideband noise of 100 nV/√Hz (1–100 kHz), and guaranteed stability over –40 °C to +125 °C with 100 ppm/°C temperature coefficient - enabling high-accuracy closed-loop control without external compensation in most applications.

Key Specifications

Pinout & Package

SOT23-3L is a surface-mount plastic micropackage (2.90 × 2.10 × 1.12 mm) with gull-wing leads, optimized for space-constrained PCB layouts and automated assembly. Thermal resistance R_thJA = 340 °C/W enables 360 mW power dissipation at T_amb = 25 °C.

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 TS3431CILT uniquely balances ±0.25% accuracy, 100 mA sink capacity, and SOT23-3L footprint - making it optimal for space-constrained, high-current feedback applications like USB-PD adapters and multi-cell battery management systems.

Availability

TS3431CILT is available at Aetrix Electronics and suitable for battery chargers, switch-mode power supplies, and portable instrumentation requiring stable component supply with guaranteed long-term availability and consistent parametric performance.

Supply support for TS3431CILT 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, and analog components for industrial, automotive, and consumer markets.

The TS3431 series belongs to ST's precision analog portfolio, engineered specifically for high-stability voltage reference applications in power conversion and measurement systems where accuracy, thermal drift, and compact packaging are critical.

FAQ

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

The TS3431CILT requires a minimum cathode current of 0.5 mA across –40 °C to +125 °C to maintain regulation, as confirmed in Table 2 of DS3673 Rev 7. This value is higher than the 0.35 mA typical at 25 °C, ensuring stable operation in cold-start conditions of outdoor power equipment.

Can TS3431CILT replace TL431 in existing designs without layout changes?

Yes - TS3431CILT uses identical SOT23-3L pinout (Cathode-Reference-Anode) and matches TL431's functional behavior, including compatible gain and dynamic impedance. No PCB redesign is needed, though resistor values may require minor adjustment to account for its tighter ±0.25% tolerance.

How does the 100 ppm/°C temperature coefficient impact 12-bit ADC reference accuracy?

Over –40 to +105 °C, the 100 ppm/°C TC causes ≤21 mV drift in the 1.24 V reference, translating to ~1.7 LSB error in a 12-bit system with 5 V full-scale range. For sub-LSB stability, external calibration or temperature compensation is recommended.

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

At T_amb = 85 °C, maximum power dissipation is calculated as (150 °C – 85 °C) / 340 °C/W = 191 mW, per absolute maximum ratings in Table 1 (DS3673 Rev 7). This limits continuous cathode current to ~79 mA when V_KA = 24 V, assuming no additional board-level heatsinking.