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 TS3431CIZ-AP

Name: TS3431CIZ-AP
Brand: STMicroelectronics
SKU: TS3431CIZ-AP
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: TS3431CIZ-AP

Manufacturer:: STMicroelectronics

Category:: Voltage Reference

Package:: TO-236-3, SC-59, SOT-23-3

Datasheet:: TS3431CIZ-AP.pdf

Description:: IC VREF SHUNT ADJ 0.25% SOT23-3

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:1,975

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

Product details

Overview

TS3431CIZ-AP from STMicroelectronics is a precision programmable shunt voltage reference 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 in TO-92 package. It delivers stable reference voltage for feedback loops in isolated DC-DC converters and battery charger regulation circuits.

For engineers reviewing the TS3431CIZ-AP datasheet, TS3431CIZ-AP pinout, TS3431CIZ-AP application, or TS3431CIZ-AP equivalent, key selection criteria include reference voltage tolerance, temperature coefficient (100 ppm/°C), cathode current range (0.5–100 mA), dynamic impedance (0.2–0.4 Ω), and TO-92 thermal performance (R_thja = 200°C/W).

Technical Context

The TS3431CIZ-AP implements a two-terminal shunt topology where cathode-anode voltage is regulated by internal bandgap reference and error amplifier driving an NPN output stage. Its reference input current (I_REF) remains below 1.5 µA across temperature, minimizing resistor-divider loading error in precision feedback networks.

It operates as a voltage-controlled current sink: when cathode voltage exceeds the programmed reference (V_REF × (1 + R1/R2)), it draws current to clamp the node. This enables direct use in optocoupler-coupled secondary-side regulation without additional biasing components.

Key Specifications

Parameter	Value and Actual Design Meaning
Reference Voltage Accuracy	±0.25% at 25°C (1.237–1.243 V); ensures ≤3 mV absolute error in 1.24 V setpoint designs
Temperature Coefficient	100 ppm/°C over –40°C to +125°C; contributes ≤2.5 mV drift across full range
Cathode Operating Current	0.5–100 mA; supports high-gain optocoupler drive and low-current standby modes
Dynamic Impedance	0.2–0.4 Ω at 1–100 mA; maintains tight regulation under fast load transients
Wideband Noise	100 nV/√Hz (1–100 kHz); avoids noise-induced instability in sensitive feedback paths
Off-State Cathode Current	≤2 µA at –40°C to +125°C; minimizes quiescent power loss in battery-backed systems

Pinout & Package

TS3431CIZ-AP uses the standard TO-92 through-hole plastic package (3-pin, straight lead configuration) with 2.54 mm lead pitch and 5.0 mm body height. Thermal resistance is R_thja = 200°C/W (free air) and R_thjc = 66°C/W (junction-to-case).

Pin/Terminal	Circuit Role	Design Meaning
Anode (Pin 1)	Reference ground return path	Must be connected to system ground or feedback node common point; carries I_REF (≤1.5 µA) and sets lower voltage boundary
Reference (Pin 2)	Internal bandgap reference input	Connected to external resistor divider midpoint; senses regulated voltage and controls cathode conduction
Cathode (Pin 3)	Current-sink output terminal	Sinks up to 100 mA to maintain V_K = V_REF × (1 + R1/R2); connects to optocoupler LED anode or error amplifier output

Key Features

Feature	Design Value
Adjustable reference voltage range	1.24–24 V via two-resistor divider; eliminates need for multiple fixed-voltage references
Guaranteed industrial temperature stability	Specified performance from –40°C to +125°C; validated across full range, not just 25°C typicals
Low reference input current	≤1.5 µA max at 125°C; reduces resistor-divider power loss and ratio error in high-impedance networks
Low dynamic impedance	0.2–0.4 Ω; enables stable regulation even with high-frequency ripple on cathode supply
ESD robustness	2 kV HBM rating; withstands handling and board assembly without protection diodes

Applications

Switch Mode Power Supply

Battery Charger

Use Scenario: Secondary-side voltage feedback in isolated flyback or forward converters using optocoupler isolation.

IC Role / Device Role / Timing Role: Shunt reference providing precise 2.5 V or 5 V feedback threshold to optocoupler LED driver.

Use Value: Enables ±1% output regulation across line, load, and temperature with minimal external components.

Use Scenario: Constant-voltage/constant-current transition detection in Li-ion or lead-acid battery chargers.

IC Role / Device Role / Timing Role: Precision voltage comparator reference for charge termination circuitry.

Use Value: Ensures accurate 4.2 V per cell cutoff (±10.5 mV) preventing overcharge and extending battery life.

Instrumentation

Computer Power Management

Use Scenario: Calibration reference in portable multimeters and data loggers requiring stable mid-supply bias points.

IC Role / Device Role / Timing Role: Programmable 2.048 V or 4.096 V reference for 12-bit ADC front-end scaling.

Use Value: Delivers <1 LSB error contribution over –40°C to +85°C due to low TC and tight initial tolerance.

Use Scenario: +3.3 V and +5 V rail monitoring in ATX or EPS motherboard VRM supervision circuits.

IC Role / Device Role / Timing Role: Adjustable threshold detector feeding supervisor IC reset inputs.

Use Value: Allows single-component solution for multiple rail fault thresholds without trimming resistors.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TL431ACZ	±1% initial accuracy (1.225–1.275 V), higher TC (130 ppm/°C), 0.5–100 mA I_K	Lower accuracy limits use in <±0.5% regulation systems; wider V_REF spread increases resistor tolerance sensitivity	Select when cost priority outweighs precision; verify thermal drift impact on long-term calibration stability
LM4040CIM3-ADJ	±0.5% accuracy, 3-terminal series topology, 60 µA max I_Q, fixed 1.2 V base reference	Requires external op-amp for adjustable output; unsuitable for direct optocoupler drive due to series architecture	Prefer for low-quiescent current sensor biasing; avoid in shunt-based SMPS feedback where cathode sinking is required

Compared with TL431ACZ and LM4040CIM3-ADJ, TS3431CIZ-AP provides tighter initial tolerance and lower temperature drift for high-accuracy feedback, while maintaining direct compatibility with legacy TL431 PCB footprints in TO-92 form factor-enabling drop-in upgrades without layout change.

Availability

TS3431CIZ-AP is available at Aetrix Electronics and suitable for switch mode power supplies, battery chargers, instrumentation, and computer power management systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TS3431CIZ-AP 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, analog ICs, and MEMS sensors for industrial, automotive, and consumer markets.

The TS3431 belongs to ST's precision analog voltage reference product line, engineered specifically for high-stability feedback control in isolated power conversion and battery management systems where accuracy, temperature resilience, and reliability are critical.

FAQ

What is the minimum cathode operating current for TS3431CIZ-AP at –40°C?

The minimum cathode operating current (I_KMIN) is 0.5 mA across the full industrial temperature range of –40°C to +125°C, as specified in Table 2 of the datasheet. This ensures reliable turn-on and regulation stability during cold-start conditions in outdoor or automotive environments.

Can TS3431CIZ-AP replace TL431 in existing TO-92 designs?

Yes-TS3431CIZ-AP shares identical TO-92 pinout (Anode–Reference–Cathode), same mechanical dimensions, and compatible electrical behavior. Its tighter 0.25% tolerance and lower 100 ppm/°C TC improve regulation accuracy without requiring PCB changes or schematic updates.

What is the maximum cathode-to-anode voltage rating?

The absolute maximum cathode-to-anode voltage (V_KA) is 25 V, per Table 1. Operating above this risks permanent damage. For 24 V output designs, ensure transient clamping or derating to maintain safe margin under surge conditions.

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

I_REF is ≤1.5 µA at +125°C and flows into the Reference pin, creating a small but measurable error in high-value resistor dividers. To limit error to <0.1%, total divider resistance should be ≤100 kΩ (e.g., 24 kΩ + 75 kΩ for 5 V output), verified in Figure 4 test circuit.

TS3431CIZ-AP Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Package/Case:: TO-236-3, SC-59, SOT-23-3

Series:: -

Packaging:: Tape & Box (TB)

Product Status:: Obsolete

Reference Type:: Shunt

Output Type:: Adjustable

Voltage - Output (Min/Fixed):: 1.24V

Voltage - Output (Max):: 24 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:: 500 µA

Operating Temperature:: -40°C ~ 125°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3

TS3431CIZ-AP FAQ

1.How can I place an order for TS3431CIZ-AP through Aetrix?

Please submit a Request for Quotation (RFQ) for TS3431CIZ-AP 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 TS3431CIZ-AP reliable?

The price and inventory of TS3431CIZ-AP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TS3431CIZ-AP is usually 5 days.

3.What payment methods are accepted for TS3431CIZ-AP?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TS3431CIZ-AP transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for TS3431CIZ-AP?

TS3431CIZ-AP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your TS3431CIZ-AP 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 TS3431CIZ-AP?

For technical support, including TS3431CIZ-AP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TS3431CIZ-AP requirements.

6.How does Aetrix verify that TS3431CIZ-AP is sourced from the original manufacturer or authorized distributors?

All TS3431CIZ-AP 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 TS3431CIZ-AP meets industry standards.

7.What is the process for return or replacement of TS3431CIZ-AP?

All TS3431CIZ-AP units undergo pre-shipment inspection (PSI). If there is an issue with TS3431CIZ-AP, 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 TS3431CIZ-AP part is unused and in its original packaging.

Return procedure for TS3431CIZ-AP:

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…