STMicroelectronics TS2431AILT

Overview

TS2431AILT from STMicroelectronics is a precision adjustable shunt voltage reference IC with 1% initial accuracy at 25 °C, 2.5–24 V programmable output, ±35 mV total V_REF deviation over –40 to +105 °C, 0.75 Ω dynamic impedance, and 1–100 mA sink current capability-used in feedback loops of isolated DC-DC converters and battery charger voltage regulation.

For engineers reviewing the TS2431AILT datasheet, TS2431AILT pinout, TS2431AILT application, or TS2431AILT equivalent, key selection criteria include temperature coefficient (50–100 ppm/°C), cathode-to-anode voltage range (V_REF to 24 V), off-state cathode leakage (<500 nA), wide-band noise (300 nV/√Hz), and SOT23-3L thermal resistance (R_thja = 340 °C/W).

Technical Context

The TS2431AILT implements a two-terminal shunt topology where the reference input (REF) senses voltage across an external resistor divider, and the cathode (K) sinks current to regulate the anode (A) node voltage. Its internal bandgap core delivers stable 2.5 V reference with trimming for 1% tolerance at 25 °C.

It operates across –40 to +105 °C with guaranteed ΔV_REF ≤ 35 mV and TC ≤ 100 ppm/°C, supports dynamic load steps via low 0.75 Ω Z_KA, and maintains stability with capacitive loads up to 1 nF per manufacturer test conditions.

Key Specifications

Pinout & Package

TS2431AILT is housed in a compact SOT23-3L surface-mount package (2.9 mm × 2.8 mm × 1.1 mm), optimized for space-constrained PCB layouts and compatible with standard reflow profiles (lead temp ≤ 260 °C for 10 s).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431ACDBVR and MAX6008AEUR+T, TS2431AILT uniquely combines 1% accuracy, 2.5–24 V adjustability, and industrial temperature stability-making it optimal for multi-output SMPS and programmable power systems where flexibility and thermal robustness are co-prioritized.

Availability

TS2431AILT is available at Aetrix Electronics and suitable for isolated DC-DC converters, battery charger regulation, and programmable power supplies requiring stable component supply with full industrial temperature grade compliance.

Supply support for TS2431AILT 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, designing and manufacturing microcontrollers, power ICs, sensors, and analog components for industrial, automotive, and consumer markets.

The TS2431 series belongs to ST's precision analog voltage reference product line, engineered specifically for high-reliability feedback regulation in isolated power conversion and battery management systems.

FAQ

What is the minimum operating current for TS2431AILT across its full temperature range?

The minimum cathode operating current (I_KMIN) is 1 mA over –40 to +105 °C, as specified in Table 3 of the datasheet. Below this, regulation is not guaranteed due to insufficient internal bias current for the bandgap core and error amplifier. At 25 °C, I_KMIN drops to 0.3–0.8 mA, but system design must ensure ≥1 mA under worst-case thermal conditions.

Can TS2431AILT replace TL431 in existing designs without layout changes?

Yes-TS2431AILT uses the same SOT23-3L pinout (A-K-REF) and matches TL431's electrical behavior in shunt mode. However, the REF pin's lower input current (0.5–2.5 µA vs TL431's ~2 µA typ.) may require minor resistor value adjustments to maintain identical divider loading and loop gain.

How does the 1% accuracy grade affect long-term stability in battery charger applications?

The 1% initial tolerance applies only at 25 °C; long-term stability is governed by temperature drift (≤35 mV over –40 to +105 °C) and aging (not specified in datasheet). In battery chargers, this translates to <±0.3% output voltage shift over lifetime under thermal cycling-well within Li-ion CV-phase tolerance limits.

What is the maximum capacitive load the TS2431AILT can drive while maintaining stability?

Per Figure 15 (Stability boundary conditions) in the datasheet, TS2431AILT remains stable with capacitive loads up to 1 nF when used with recommended compensation (e.g., series resistor between REF and divider). Loads >1 nF risk phase margin reduction and potential oscillation in high-gain feedback configurations.