STMicroelectronics TS3431CIZT

Overview

TS3431CIZT from STMicroelectronics is a programmable shunt voltage reference IC with 0.25% initial accuracy (1.237–1.243 V at 25°C), adjustable output from 1.24 V to 24 V via external resistors, and guaranteed operation from –40°C to +125°C. It delivers sink current up to 100 mA and features low dynamic impedance (0.2–0.4 Ω) and wideband noise of 100 nV/√Hz - used in precision feedback loops of isolated DC-DC converters.

For engineers reviewing the TS3431CIZT datasheet, TS3431CIZT pinout, TS3431CIZT application, or TS3431CIZT equivalent, key selection criteria include reference voltage tolerance over temperature, minimum operating current (0.5 mA across full range), cathode-anode voltage rating (25 V), and TO-92 package thermal resistance (R_thja = 200°C/W).

Technical Context

The TS3431CIZT implements a two-terminal shunt topology with internal bandgap reference and error amplifier, enabling precise regulation by sinking variable current through an external resistor divider. Its reference input current remains ultra-low (≤1.5 µA at 25°C) and stable across temperature (≤2 µA over –40°C to +125°C), minimizing divider loading error.

It achieves ±0.25% initial accuracy and <21 mV total reference voltage drift over –40°C to +125°C, supported by a 100 ppm/°C temperature coefficient. The device maintains stable dynamic impedance (<0.4 Ω) from 1 kHz to 100 kHz, ensuring robust loop stability in switch-mode power supply feedback networks.

Key Specifications

Pinout & Package

TS3431CIZT is housed in a TO-92 plastic package (3-pin, through-hole), with standard pinout: Pin 1 = Anode, Pin 2 = Cathode, Pin 3 = Reference (adjust) terminal. The package supports manual soldering (lead temp ≤250°C for 10 s) and offers R_thja = 200°C/W 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 TL431CDBZR and MAX6008AEUR+T, TS3431CIZT uniquely combines 0.25% accuracy, full industrial temperature support, and 1.24–24 V adjustability in a TO-92 package - making it optimal for cost-sensitive, high-stability isolated power and battery systems where flexibility and ruggedness are jointly required.

Availability

TS3431CIZT is available at Aetrix Electronics and suitable for isolated flyback power supplies, battery charger feedback circuits, and programmable lab power supplies requiring stable component supply with consistent parametric performance across production lots.

Supply support for TS3431CIZT 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 analog, MCU, power, and sensing solutions for industrial, automotive, and consumer markets.

The TS3431 series belongs to ST's precision analog portfolio, engineered specifically for high-accuracy, temperature-stable shunt references in space-constrained and thermally demanding power management applications.

FAQ

What is the maximum cathode-to-anode voltage the TS3431CIZT can withstand?

The absolute maximum cathode-to-anode voltage (V_KA) is 25 V. Exceeding this risks permanent breakdown. In normal operation, the device regulates by sinking current when V_KA exceeds the programmed reference voltage (1.24–24 V), so design must ensure V_KA never surpasses 25 V under fault or transient conditions.

Can TS3431CIZT replace TL431 in existing designs without modification?

Yes - TS3431CIZT is pin-compatible with TL431 in TO-92 and shares identical pinout (Anode, Cathode, Reference). However, its tighter 0.25% tolerance and lower minimum operating current (0.5 mA vs. 1 mA) may require minor feedback resistor recalibration to maintain target output voltage and loop stability.

How does the reference input current (I_REF) affect feedback divider design?

I_REF is ≤2 µA over temperature and flows into the Reference pin. To limit voltage error from divider current mismatch, total divider current should be ≥100× I_REF (i.e., ≥200 µA). For a 12 V output with 2.5 V reference, this implies R1 + R2 ≤ 60 kΩ - ensuring accuracy remains within datasheet tolerance.

Is TS3431CIZT suitable for use in automotive under-hood environments?

Yes - its guaranteed operation from –40°C to +125°C, 2 kV HBM ESD rating, and qualified TO-92 package meet AEC-Q100 stress test requirements for ambient temperature and electrostatic robustness. However, full AEC-Q100 qualification status must be confirmed with STMicroelectronics' official part documentation before deployment in safety-critical systems.