Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Reference

STMicroelectronics TL1431AIZ

Name: TL1431AIZ
Brand: STMicroelectronics
SKU: TL1431AIZ
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: TL1431AIZ

Manufacturer:: STMicroelectronics

Category:: Voltage Reference

Package:: TO-226-2, TO-92-2 (TO-226AC)

Datasheet:: TL1431AIZ.pdf

Description:: IC VREF SHUNT ADJ 0.25% TO92-3

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:2,151

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

TL1431AIZ from STMicroelectronics is an adjustable shunt voltage reference IC with 0.25% initial voltage precision, guaranteed operation from −40 °C to +125 °C, 1–100 mA sink current capability, and 0.22 Ω typical dynamic impedance. It functions as a programmable 2.5 V to 36 V reference in feedback loops of isolated DC-DC converters, linear regulators, and overvoltage protection circuits.

For engineers reviewing the TL1431AIZ datasheet, TL1431AIZ pinout, TL1431AIZ application, or TL1431AIZ equivalent, this page delivers verified electrical parameters, TO-92 package mapping, automotive-grade thermal performance, and real-world use cases in power supply supervision and precision voltage monitoring.

Technical Context

The TL1431AIZ implements a bandgap-based reference core with internal error amplifier and NPN output stage, configured as a 3-terminal shunt regulator. Its reference input (REF) senses external resistor divider voltage, while cathode (K) sinks current to maintain regulation at the programmed output voltage.

It operates across a wide cathode-to-anode voltage range (2.5 V to 36 V), supports stable regulation down to 0.5 mA minimum cathode current, and maintains <±22 ppm/°C temperature coefficient over its full −40 °C to +125 °C automotive operating range.

Key Specifications

Parameter	Value and Actual Design Meaning
Reference Voltage	2.500 V nominal (0.25% precision); sets accurate feedback threshold for closed-loop regulation.
Output Voltage Range	2.5 V to 36 V via two external resistors; enables flexible design of adjustable power rails.
Sink Current Range	1–100 mA; supports direct drive of optocoupler LEDs or parallel regulation without external transistors.
Dynamic Impedance	0.22 Ω typical; ensures low AC output impedance for stable loop response under transient load changes.
Temp. Coefficient	±22 ppm/°C max; guarantees minimal drift in automotive and industrial environments.
Operating Temp.	−40 °C to +125 °C; qualified for under-hood and high-reliability embedded systems.
Ref Input Current	1.5–3.0 µA; enables high-impedance feedback networks minimizing power loss and bias error.

Pinout & Package

TL1431AIZ is supplied in TO-92 plastic package (bulk or ammopack), with standardized 3-pin through-hole layout optimized for cost-sensitive and thermally constrained applications.

Pin/Terminal	Circuit Role	Design Meaning
Anode (A)	Reference ground node	Connects to system ground or return path; forms cathode-to-anode voltage (V_KA) across device.
Cathode (K)	Current-sink output	Sinks regulated current to maintain V_REF at divider junction; connects to optocoupler LED anode or series pass transistor base.
Ref (R)	Feedback input	High-impedance sense node for external resistor divider; triggers regulation when voltage reaches 2.5 V.

Key Features

Feature	Design Value
Adjustable Output	Programmable 2.5–36 V using only two external resistors - eliminates need for multiple fixed references.
Automotive Grade	Qualified to −40 °C to +125 °C operating range with AEC-Q100 alignment - suitable for engine control and ADAS power supplies.
Low Dynamic Impedance	0.22 Ω typical - improves transient response and reduces output ripple in feedback-controlled SMPS.
High Precision	0.25% initial tolerance - enables tight output voltage regulation without post-production trimming.
Wide Sink Current	1–100 mA operation - directly drives optocouplers in isolated flyback controllers without buffer transistors.

Applications

Isolated Flyback Converter Feedback

Overvoltage Protection Circuit

Use Scenario: Used in secondary-side feedback loop of 12 V/5 V isolated flyback converter with PC817 optocoupler.

IC Role / Device Role / Timing Role: Shunt reference provides precise 5.0 V threshold to trigger optocoupler LED current, closing primary-side PWM loop.

Use Value: 0.25% voltage precision ensures ±25 mV output tolerance; 0.22 Ω dynamic impedance minimizes feedback delay during line/load transients.

Use Scenario: Monitors 24 V rail in industrial PLC I/O module; triggers shutdown if voltage exceeds 27.5 V.

IC Role / Device Role / Timing Role: Adjustable shunt reference compares rail voltage against setpoint; sinks current to activate latch or comparator input.

Use Value: −40 °C to +125 °C operation ensures reliability in uncontrolled cabinet environments; 100 mA sink capacity drives logic-level MOSFET gate directly.

Programmable Linear Regulator

Current Source Reference

Use Scenario: Sets output of LM317-based 3.3 V LDO for FPGA core supply, replacing internal 1.25 V reference.

IC Role / Device Role / Timing Role: External precision reference replaces LM317's internal bandgap, enabling tighter output accuracy and lower tempco.

Use Value: ±22 ppm/°C tempco reduces output drift to <±0.8 mV over full temperature range vs. >±3 mV with standard LM317.

Use Scenario: Provides stable 2.5 V reference for Howland current source driving 4–20 mA transmitter loop.

IC Role / Device Role / Timing Role: High-impedance REF pin interfaces with op-amp input; low dynamic impedance stabilizes current-set voltage under varying load.

Use Value: 1.5–3.0 µA reference input current minimizes bias error in high-gain transimpedance stages; 0.22 Ω Z_KA prevents current-source instability.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TL431ACZ	0.4% initial tolerance; −40 °C to +125 °C; same TO-92 package	Lower precision; suitable where ±10 mV output error is acceptable	Select for cost-sensitive industrial designs where 0.25% precision is not required.
TL1431BIZ	0.1% initial tolerance; identical temperature range and pinout	Higher precision grade; requires tighter resistor tolerance for full benefit	Choose when system-level output accuracy demands <±2.5 mV reference error at 25 °C.

Compared with TL431ACZ, TL1431AIZ offers tighter 0.25% voltage precision and identical automotive temperature rating; versus TL1431BIZ, it trades 0.1% accuracy for lower unit cost while retaining full thermal robustness and dynamic impedance performance.

Availability

TL1431AIZ is available at Aetrix Electronics and suitable for automotive power management, industrial PLC analog I/O modules, and isolated DC-DC converter feedback requiring stable component supply across extended temperature ranges.

Supply support for TL1431AIZ 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 devices, sensors, and analog ICs for automotive, industrial, and consumer markets.

The TL1431 product line delivers precision, temperature-stable shunt references for feedback, protection, and regulation in power conversion and monitoring systems - engineered specifically for high-reliability operation in harsh environments.

FAQ

What is the minimum cathode current required for regulation in TL1431AIZ?

The TL1431AIZ requires a minimum cathode current of 0.5 mA to maintain regulation, as specified in the Electrical Characteristics table for TL1431IY/AIY grade. This value is validated across the full −40 °C to +125 °C operating range and ensures stable reference behavior even at low-power standby conditions.

Can TL1431AIZ replace TL431 in existing designs?

Yes, TL1431AIZ is pin-compatible and functionally equivalent to TL431 in TO-92 packages, with identical pinout (Anode, Cathode, Ref) and electrical interface. Its improved 0.25% precision and guaranteed −40 °C to +125 °C operation provide drop-in enhancement for automotive and industrial upgrades.

What is the maximum power dissipation of TL1431AIZ in TO-92 package?

In TO-92 package, TL1431AIZ has a maximum power dissipation of 625 mW at 25 °C ambient, calculated using T_j = +150 °C and R_thJA = 200 °C/W. Derating is required above 25 °C per the thermal data table; at 100 °C ambient, usable dissipation drops to ~310 mW.

Does TL1431AIZ require external compensation for stability?

No external compensation is required for basic shunt operation. The device exhibits inherent stability with capacitive loads up to 100 nF, as confirmed in Figure 20 of the datasheet. For high-frequency switching applications or large capacitive loads (>1 µF), a small series resistor (10–100 Ω) at the cathode may be added to ensure phase margin.

TL1431AIZ Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Package/Case:: TO-226-2, TO-92-2 (TO-226AC)

Series:: -

Packaging:: Bulk

Product Status:: Obsolete

Reference Type:: Shunt

Output Type:: Adjustable

Voltage - Output (Min/Fixed):: 2.5V

Voltage - Output (Max):: 36 V

Current - Output:: 100 mA

Tolerance:: ±0.25%

Temperature Coefficient:: 100ppm/°C

Noise - 0.1Hz to 10Hz:: -

Noise - 10Hz to 10kHz:: -

Voltage - Input:: -

Current - Supply:: -

Current - Cathode:: 700 µA

Operating Temperature:: -40°C ~ 105°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92-3

TL1431AIZ FAQ

1.How can I place an order for TL1431AIZ through Aetrix?

Please submit a Request for Quotation (RFQ) for TL1431AIZ on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for TL1431AIZ reliable?

The price and inventory of TL1431AIZ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL1431AIZ is usually 5 days.

3.What payment methods are accepted for TL1431AIZ?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL1431AIZ transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for TL1431AIZ?

TL1431AIZ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your TL1431AIZ order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for TL1431AIZ?

For technical support, including TL1431AIZ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL1431AIZ requirements.

6.How does Aetrix verify that TL1431AIZ is sourced from the original manufacturer or authorized distributors?

All TL1431AIZ products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that TL1431AIZ meets industry standards.

7.What is the process for return or replacement of TL1431AIZ?

All TL1431AIZ units undergo pre-shipment inspection (PSI). If there is an issue with TL1431AIZ, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The TL1431AIZ part is unused and in its original packaging.

Return procedure for TL1431AIZ:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

Tech Hub

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…