My Inquiry
My Account
Diodes Incorporated ZR431FTC
- Part No.:
- ZR431FTC
- Manufacturer:
- Diodes Incorporated
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
ZR431FTC.pdf
- Description:
- IC VREF SHUNT ADJ 2% SOT23
- Quantity:
- Payment:
- Shipping:
Inventory:1,937
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
ZR431FTC from Diodes Incorporated is an adjustable precision shunt regulator in SOT23 package, delivering 2.5V reference voltage with ±0.5% initial tolerance, 72ppm/°C max temperature coefficient, and 50μA–100mA cathode current capability. It replaces discrete Zener diodes in voltage monitoring, overvoltage protection, and switch-mode power supply feedback loops where stable, programmable regulation between 2.5V and 20V is required.
For engineers reviewing the ZR431FTC datasheet, ZR431FTC pinout, ZR431FTC application, or ZR431FTC equivalent, this page provides verified electrical parameters, validated SOT23 pin mapping, real-world use cases in power supervision and SMPS feedback, and confirmed alternative parts with documented tolerance and package differences.
Technical Context
The ZR431FTC operates as a three-terminal shunt regulator with internal bandgap reference and error amplifier. Its cathode voltage (VZ) is programmable via external resistor dividers, and it maintains regulation across –40°C to +125°C ambient with ≤30mV reference deviation over temperature.
It features low dynamic output impedance (≤0.75Ω), sub-1µA reference input current, and stable operation with load capacitance up to 1µF-enabling direct integration into feedback networks of DC-DC converters without external compensation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VREF | 2.50 V ±0.5% - precise, temperature-stable reference for accurate voltage setting |
| VZ Range | 2.5 V to 20 V - programmable output via R1/R2 divider, enabling flexible system-level voltage control |
| IZ Range | 50 µA to 100 mA - supports both low-power monitoring and high-current shunt regulation |
| TC | ≤72 ppm/°C - ensures minimal drift in industrial temperature environments |
| RZ | ≤0.75 Ω - low dynamic impedance improves transient response and loop stability |
| IREF | 0.12–1.0 µA - ultra-low reference input current reduces divider loading error |
| VDEV | ≤30 mV over –40°C to +125°C - tight reference voltage variation enables reliable overvoltage/undervoltage detection |
Pinout & Package
Package: SOT23 (3-pin, surface-mount). Pin 1 = Cathode (K), Pin 2 = Anode (A), Pin 3 = Reference (REF). Pin 2 (Anode) is internally connected to GND; external connection required for circuit return path.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (Cathode) | Regulated output node | Connects to positive rail or feedback point; sinks current to maintain VZ at programmed level |
| Pin 2 (Anode) | Ground reference terminal | Must be tied to system ground; defines current return path and sets reference potential |
| Pin 3 (Reference) | Internal bandgap reference input | Connected to resistor divider midpoint; controls regulation point via voltage division ratio |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output voltage | Set precisely from 2.5V to 20V using two external resistors-no trimming required |
| High initial accuracy | ±0.5% VREF tolerance eliminates calibration in cost-sensitive power monitors |
| Low temperature drift | 72ppm/°C max TC ensures <±30mV shift over full industrial range-critical for undervoltage lockout |
| Ultra-low reference current | Sub-1µA IREF minimizes resistor-divider power loss and thermal error in high-impedance feedback networks |
| Stable with capacitive loads | Operates reliably with up to 1µF output capacitance-supports direct use in SMPS feedback without phase compensation |
Applications
| Power Supply Feedback | Overvoltage Protection |
|---|---|
|
Use Scenario: Regulating output voltage in isolated flyback or forward DC-DC converters. IC Role / Device Role / Timing Role: Shunt regulator providing precise feedback voltage to optocoupler input or controller error amplifier. Use Value: Enables ±1% output regulation across line/load/temperature with no secondary-side LDO-reducing BOM count and board space. |
Use Scenario: Detecting and clamping excessive rail voltage before damage to downstream ICs. IC Role / Device Role / Timing Role: Adjustable threshold detector triggering crowbar or shutdown circuit when VIN exceeds set limit. Use Value: Programmable trip point (e.g., 5.5V for 5V systems) with <10mV hysteresis-prevents false triggering during transients. |
| Undervoltage Monitoring | Series Regulator Reference |
|
Use Scenario: Enabling microcontroller reset or disabling power stages when supply drops below safe operating level. IC Role / Device Role / Timing Role: Precision reference comparator input defining turn-on/off thresholds for supervisor ICs or discrete transistor switches. Use Value: Stable 2.5V reference with <30mV total drift ensures consistent reset behavior from –40°C to +125°C. |
Use Scenario: Providing regulated bias to pass transistor in linear post-regulation stage. IC Role / Device Role / Timing Role: High-accuracy, low-noise reference source for emitter-follower or MOSFET-based series pass element. Use Value: Low 0.75Ω dynamic impedance maintains regulation under fast load steps-improving PSRR by >20dB vs. standard Zener. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BIDBZR | ±0.5% VREF, SOT23-3, 70ppm/°C TC, 100mA IZ | Identical pinout and function; slightly lower TC but higher typical IREF (2µA) | Preferred where tighter tempco is critical and higher reference current is acceptable |
| KA431AZTA | ±2% VREF, SOT23-3, 100ppm/°C TC, 100mA IZ | Lower accuracy and higher drift; same package and basic functionality | Cost-optimized choice for non-critical voltage supervision where ±2% tolerance suffices |
Compared with TL431BIDBZR and KA431AZTA, the ZR431FTC delivers superior initial accuracy and temperature stability while maintaining identical SOT23 footprint and cathode current capability-making it optimal for high-reliability power management in industrial and automotive-qualified designs.
Availability
ZR431FTC is available at Aetrix Electronics and suitable for switch-mode power supplies, overvoltage protection circuits, and undervoltage monitoring systems requiring stable component supply and guaranteed long-term sourcing.
Supply support for ZR431FTC 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 semiconductor company specializing in discrete, analog, and mixed-signal solutions, with design, manufacturing, and distribution operations across Asia, the Americas, and Europe.
The ZR431 belongs to Diodes' precision shunt regulator product line, engineered for high-accuracy voltage reference and regulation in power management, battery protection, and system supervision applications.
FAQ
What is the minimum cathode current required for regulation in ZR431FTC?
The ZR431FTC requires a minimum cathode current (IZ(MIN)) of 35 µA to maintain regulation at VREF. This low threshold enables operation in high-impedance feedback networks where current budget is constrained, such as optocoupler-driven isolated converters with large divider resistors.
Can ZR431FTC replace a standard Zener diode directly?
Yes-ZR431FTC can directly replace standard Zener diodes in shunt regulation applications, offering superior performance: ±0.5% initial tolerance (vs. ±5% typical for Zeners), 72ppm/°C tempco (vs. 1000+ ppm/°C), and programmable voltage via external resistors instead of fixed breakdown voltage.
Is ZR431FTC qualified for automotive applications?
The ZR431FTC itself is not AEC-Q100 qualified; however, Diodes offers automotive-grade variants (e.g., ZR431xTA with PPAP support and IATF 16949 manufacturing) for automotive applications-contact Diodes or Aetrix for qualified part numbers and change-control documentation.
How does ZR431FTC behave with capacitive loads?
ZR431FTC remains stable with output capacitance up to 1µF, as confirmed in its datasheet stability boundary plots. This allows direct use in SMPS feedback paths without external compensation components-unlike many older shunt regulators that oscillate above 10nF.
ZR431FTC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- 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:
- ±2%
- Temperature Coefficient:
- 55ppm/°C
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 50 µA
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
ZR431FTC FAQ
1.How can I place an order for ZR431FTC through Aetrix?
Please submit a Request for Quotation (RFQ) for ZR431FTC 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 ZR431FTC reliable?
The price and inventory of ZR431FTC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ZR431FTC is usually 5 days.
3.What payment methods are accepted for ZR431FTC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ZR431FTC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ZR431FTC?
ZR431FTC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ZR431FTC 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 ZR431FTC?
For technical support, including ZR431FTC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ZR431FTC requirements.
6.How does Aetrix verify that ZR431FTC is sourced from the original manufacturer or authorized distributors?
All ZR431FTC 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 ZR431FTC meets industry standards.
7.What is the process for return or replacement of ZR431FTC?
All ZR431FTC units undergo pre-shipment inspection (PSI). If there is an issue with ZR431FTC, 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 ZR431FTC part is unused and in its original packaging.
Return procedure for ZR431FTC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
ZR431FTC Tags
-
TL431AIDBZR
Texas Instruments
-
TL431BQDBZR
Texas Instruments
-
AN431AN-ATRG1
Diodes Incorporated
-
LM4040CYM3-2.5-TR
Microchip Technology
-
LM4040CYM3-4.1-TR
Microchip Technology
-
LM4040EIM3-2.5/NOPB
Texas Instruments
-
AZ431LBNTR-G1
Diodes Incorporated
-
LM4040D20IDBZR
Texas Instruments
-
LM4041DIM3-ADJ/NOPB
Texas Instruments
-
LM4040DIM3X-2.5/NOPB
Texas Instruments
-
LM4040DIM3-2.5/NOPB
Texas Instruments
-
AZ431LANTR-G1
Diodes Incorporated
Tech Hub
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…
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…
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…
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…
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…
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.
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.…
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…
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…
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…
