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

Diodes Incorporated ZTL431AQFFTA

Name: ZTL431AQFFTA
Brand: Diodes Incorporated
SKU: ZTL431AQFFTA
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: ZTL431AQFFTA

Manufacturer:: Diodes Incorporated

Category:: Voltage Reference

Package:: SOT-23-3 Flat Leads

Datasheet:: ZTL431AQFFTA.pdf

Description:: IC VREF SHUNT ADJ 1% SOT23F

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:3,299

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

Product details

Overview

ZTL431AQFFTA from Diodes Incorporated is an automotive-grade adjustable precision shunt regulator in SOT23F package, featuring 1% initial reference voltage tolerance (2.5 V ±1%), -40°C to +125°C operating range, 0.2 Ω typical dynamic output impedance, and 1–100 mA sink current capability. It functions as a programmable voltage reference in feedback loops for linear regulators, opto-coupler linearization, and over/under-voltage protection circuits in automotive power management systems.

For engineers reviewing the ZTL431AQFFTA datasheet, ZTL431AQFFTA pinout, ZTL431AQFFTA application, or ZTL431AQFFTA equivalent, this device requires attention to cathode-anode voltage limits (up to 20 V), minimum regulation current (0.4–0.6 mA), stability with ≥4.7 nF anode-cathode capacitance, and AEC-Q100 Grade 1 qualification for PPAP-compliant automotive designs.

Technical Context

The ZTL431AQFFTA implements a bandgap-based 2.5 V reference with internal error amplifier and NPN output stage, configured as a three-terminal shunt regulator. Its reference input (REF) senses voltage via external resistor divider, while cathode (K) sinks current to maintain regulated voltage across anode (A) and cathode terminals.

It operates with adjustable output from 2.5 V to 20 V using two external resistors, exhibits low temperature drift (≤34 mV deviation over -40°C to +125°C), and maintains stable operation under capacitive loads ≥4.7 nF between anode and cathode - critical for automotive feedback loop integrity.

Key Specifications

Parameter	Value and Actual Design Meaning
V_REF	2.5 V ±1% at +25°C - sets precise regulation threshold for feedback networks
V_{K A} Max	20 V - defines maximum cathode-to-anode voltage before breakdown
I_{K A} Range	1–100 mA - supports wide load current adjustment without external transistor
R_Z	0.2 Ω typical - ensures tight output regulation under dynamic load transients
T_A Range	-40°C to +125°C - meets AEC-Q100 Grade 1 ambient requirements for engine bay and ADAS modules
I_{K A(MIN)}	0.4–0.6 mA - minimum current needed to sustain regulation, critical for low-power standby modes
ΔV_REF	≤34 mV over full temp range - guarantees reference stability across automotive thermal cycles

Pinout & Package

SOT23F package (3-pin, 2.9 mm × 2.4 mm × 0.9 mm), thermally enhanced for 720 mW power dissipation at +25°C ambient. Pin 1 = Cathode (K), Pin 2 = Anode (A), Pin 3 = Reference (REF).

Pin/Terminal	Circuit Role	Design Meaning
Pin 1 (Cathode)	Sink output terminal	Carries regulated load current to ground or return path; connects to feedback node of downstream regulator
Pin 2 (Anode)	Reference return path	Common return for reference divider and cathode current; must be tied to system ground or low-impedance return
Pin 3 (Reference)	Feedback sense input	High-impedance input monitoring voltage divider output; determines regulated output via R1/R2 ratio

Key Features

Feature	Design Value
Automotive qualification	AEC-Q100 Grade 1 qualified with PPAP documentation support - enables direct use in safety-critical vehicle subsystems
Thermal performance	θ_JA = 138°C/W in SOT23F - enables higher continuous power handling than standard SOT23 (380°C/W)
Stability assurance	Guaranteed stable with ≥4.7 nF anode–cathode capacitor - eliminates need for complex compensation in automotive feedback paths
Green compliance	Fully RoHS-compliant, halogen- and antimony-free - satisfies EU automotive environmental mandates without derating
Low I_REF	2–4 µA typical reference input current - minimizes divider resistor power loss and improves efficiency in battery-sensitive applications

Applications

Opto-Coupler Linearization

Linear Regulator Feedback

Use Scenario: Improving linearity and bandwidth of isolated feedback in automotive DC-DC converters using opto-couplers.

IC Role / Device Role / Timing Role: Shunt regulator provides stable 2.5 V reference to drive opto-LED, enabling accurate secondary-side voltage sensing.

Use Value: Reduces cross-regulation error by >40% versus zener diodes and supports <1% output voltage tolerance over temperature and lifetime.

Use Scenario: Setting precise output voltage in adjustable LDOs for infotainment SoC power rails.

IC Role / Device Role / Timing Role: Adjustable shunt reference replaces fixed zener in feedback divider, enabling programmable 3.3 V/5 V/12 V outputs.

Use Value: Enables single-BOM flexibility across multiple voltage variants while maintaining ±1% regulation accuracy per AEC-Q100 test plan.

Over/Under-Voltage Protection

Variable Reference Generator

Use Scenario: Monitoring battery voltage in 12 V automotive systems to trigger shutdown during cranking or overcharge.

IC Role / Device Role / Timing Role: Configured as comparator with hysteresis using dual resistor networks on REF pin.

Use Value: Achieves ±15 mV trip threshold accuracy over -40°C to +125°C, eliminating need for external precision references.

Use Scenario: Generating temperature-compensated thresholds for battery cell monitoring in EV BMS front-ends.

IC Role / Device Role / Timing Role: Paired with NTC thermistor in R1/R2 divider to produce voltage thresholds that track battery chemistry characteristics.

Use Value: Delivers <±0.5% threshold drift over full temperature range, improving state-of-charge estimation resolution by 2× versus discrete solutions.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TL431ACDBVR	Commercial-grade (non-AEC-Q100), 2.495–2.505 V tolerance, SOT23-5 package with NC pin	Lacks automotive qualification, wider temp range (-40°C to +125°C not guaranteed), no PPAP support	Select only for non-automotive industrial or consumer applications where AEC-Q100 is not required
ZTL432AQFFTA	Identical electrical specs but different pinout: Pin 1 = REF, Pin 2 = Cathode, Pin 3 = Anode	Requires PCB layout revision; incompatible with ZTL431AQFFTA footprint without redesign	Choose when existing design uses TL432-compatible pin mapping or requires alternate routing topology

Compared with TL431ACDBVR, ZTL431AQFFTA delivers guaranteed AEC-Q100 Grade 1 reliability and tighter production lot control, while ZTL432AQFFTA offers identical performance with inverted pin assignment - both require explicit validation of board-level stability and thermal margin in final automotive assembly.

Availability

ZTL431AQFFTA is available at Aetrix Electronics and suitable for automotive power management, battery monitoring, and isolated feedback systems requiring stable component supply with full PPAP documentation and AEC-Q100 traceability.

Supply support for ZTL431AQFFTA 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design centers across Asia and manufacturing in Taiwan and China.

ZTL431 series belongs to Diodes' Automotive Compliant product line, engineered specifically for high-reliability vehicle subsystems including body electronics, ADAS power supplies, and battery management interfaces - emphasizing AEC-Q100 qualification, extended temperature operation, and PPAP-ready documentation.

FAQ

What is the minimum cathode current required for regulation in ZTL431AQFFTA?

The ZTL431AQFFTA requires a minimum cathode current of 0.4–0.6 mA to maintain regulation, as specified in the Electrical Characteristics table under I_{K A(MIN)}. This value is measured at V_{K A} = V_REF and ensures stable reference operation even in ultra-low-power sleep modes of automotive ECUs.

Can ZTL431AQFFTA replace TL431 in existing designs?

ZTL431AQFFTA is functionally compatible with TL431 in electrical behavior but differs in qualification: it is AEC-Q100 Grade 1 qualified, rated for -40°C to +125°C operation, and features tighter 1% reference tolerance. Physical replacement requires verification of SOT23F thermal performance and stability with ≥4.7 nF anode–cathode capacitance.

Why does ZTL431AQFFTA require a minimum 4.7 nF capacitor between anode and cathode?

The 4.7 nF capacitor ensures stability across the full operating range by damping phase shift in the internal error amplifier loop, as confirmed in the Stability Boundary graph (page 4 of DS36916). Without it, oscillation may occur under certain load and trace inductance conditions common in automotive PCB layouts.

Is ZTL431AQFFTA pin-compatible with ZTL432AQFFTA?

No - ZTL431AQFFTA (Pin 1 = Cathode, Pin 2 = Anode, Pin 3 = REF) and ZTL432AQFFTA (Pin 1 = REF, Pin 2 = Cathode, Pin 3 = Anode) have opposite pinouts in the same SOT23F package. Direct substitution causes functional failure; PCB redesign or adapter is required for migration.

ZTL431AQFFTA Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Package/Case:: SOT-23-3 Flat Leads

Series:: -

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Reference Type:: Shunt

Output Type:: Adjustable

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

Voltage - Output (Max):: 20 V

Current - Output:: 100 mA

Tolerance:: ±1%

Temperature Coefficient:: 121ppm/°C

Noise - 0.1Hz to 10Hz:: -

Noise - 10Hz to 10kHz:: -

Voltage - Input:: -

Current - Supply:: -

Current - Cathode:: 600 µA

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

Grade:: Automotive

Qualification:: AEC-Q100

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23F

ZTL431AQFFTA FAQ

1.How can I place an order for ZTL431AQFFTA through Aetrix?

Please submit a Request for Quotation (RFQ) for ZTL431AQFFTA 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 ZTL431AQFFTA reliable?

The price and inventory of ZTL431AQFFTA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ZTL431AQFFTA is usually 5 days.

3.What payment methods are accepted for ZTL431AQFFTA?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ZTL431AQFFTA transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for ZTL431AQFFTA?

ZTL431AQFFTA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your ZTL431AQFFTA 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 ZTL431AQFFTA?

For technical support, including ZTL431AQFFTA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ZTL431AQFFTA requirements.

6.How does Aetrix verify that ZTL431AQFFTA is sourced from the original manufacturer or authorized distributors?

All ZTL431AQFFTA 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 ZTL431AQFFTA meets industry standards.

7.What is the process for return or replacement of ZTL431AQFFTA?

All ZTL431AQFFTA units undergo pre-shipment inspection (PSI). If there is an issue with ZTL431AQFFTA, 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 ZTL431AQFFTA part is unused and in its original packaging.

Return procedure for ZTL431AQFFTA:

1.Submit a request within 90 days.

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

Tech Hub

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…

2026-08-18 Operational Amplifier (Op Amp): Basics, Configurations, Feedback and Applications

Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…

2026-08-14 Jumper Cables: How to Use, Connect and Choose Them Safely

Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…

2026-08-11 LDO Regulator: Dropout Voltage, Noise, PSRR and Power Dissipation

LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…

2026-08-06 Conditional Access Module: CAM, CI/CI+ and DVB Security

Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…

2026-08-03 Electronic Component Obsolescence: EOL Risks, Replacement Options and Last-Time Buy Strategy

Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.

2026-07-29 18650 Battery: Voltage, Capacity, Charging and Pack Design

18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…

2026-07-27 Hall Effect Sensor: Working Principle, Types, Circuits and Applications

Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…

2026-07-20 Product Change Notification (PCN) in Electronic Components: Meaning and Supply Chain Response

Product Change Notification guide for electronic components, covering PCN meaning, PCN vs PDN/EOL, common change types, risk levels, form-fit-function review, engineering validation, BOM control, LTB/L…

2026-07-19 Blend Door Actuator: Symptoms, Location, Reset and Replacement Guide

A practical guide to blend door actuators, covering HVAC function, symptoms, location, AC and heater issues, reset and calibration, replacement cost, electrical diagnosis, compatibility checks, and rep…