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Diodes Incorporated TLV431TFTA
- Part No.:
- TLV431TFTA
- Manufacturer:
- Diodes Incorporated
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TLV431TFTA.pdf
- Description:
- IC VREF SHUNT ADJ 0.2% SOT23
- Quantity:
- Payment:
- Shipping:
Inventory:1,787
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Product details
Overview
TLV431TFTA from Diodes Incorporated is a precision 1.24V adjustable shunt voltage regulator in SOT23 package, rated for ±0.2% initial reference voltage tolerance at +25°C, -40°C to +125°C operating temperature, and 20mA max cathode current. It replaces Zener diodes in isolated feedback loops of AC/DC adapters and DC-DC converters requiring tight regulation and low drift.
For engineers reviewing the TLV431TFTA datasheet, TLV431TFTA pinout, TLV431TFTA application, or TLV431TFTA equivalent, this page delivers verified electrical parameters, validated SOT23 pin mapping, real-world isolated PSU and series regulator use cases, and two confirmed drop-in alternatives with documented tolerance and thermal drift differences.
Technical Context
The TLV431TFTA operates as a 3-terminal shunt regulator where the REF pin senses voltage via external resistor divider, and the device sinks cathode current to maintain VREF = 1.24V across the divider. Its internal bandgap reference and error amplifier enable stable regulation without external compensation.
It supports adjustable output voltages from 1.24V to 18V using two external resistors, exhibits 0.25Ω typical dynamic output impedance, and maintains ≤11mV reference deviation over -40°C to +125°C - critical for automotive and industrial power supply feedback paths.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VREF | 1.24V nominal reference voltage; sets minimum regulated output in shunt configurations (e.g., 2.7V isolated supply with optocoupler). |
| Reference Tolerance | ±0.2% at +25°C (TLV431T grade); enables high-accuracy feedback in <1% output tolerance power supplies. |
| Temp Drift (–40°C to +125°C) | 11mV max deviation; ensures stable regulation across extended industrial and automotive ambient ranges. |
| Cathode Current Range | 55µA to 15mA min/max for regulation; defines minimum bias current and maximum shunt capability in feedback networks. |
| Dynamic Output Impedance | 0.25Ω typical; provides low-impedance reference node for fast transient response in closed-loop systems. |
| Max Cathode Voltage | 20V absolute rating; allows direct use in 12V/15V secondary-side rails without external clamping. |
| Min Cathode Current | 55µA at –40°C to +125°C; determines smallest series resistor value needed for guaranteed regulation under worst-case conditions. |
Pinout & Package
TLV431TFTA is housed in a RoHS-compliant SOT23-3 package (JEDEC TO-236AB), with die attached to pin 2 (Cathode). Pin 1 = Cathode, Pin 2 = Anode, Pin 3 = Reference. Anode must be connected to system ground or lowest potential node; REF requires external resistor divider to set output voltage.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Cathode) | Current sink terminal | Connects to unregulated input rail via series resistor; sinks variable current to maintain VREF at pin 3. |
| 2 (Anode) | Ground reference terminal | Must be tied to system ground or common return path; forms reference node for internal error amplifier. |
| 3 (REF) | Feedback sense input | Monitors voltage divider output; regulates cathode current until divider voltage equals 1.24V. |
Key Features
| Feature | Design Value |
|---|---|
| Low-voltage reference | 1.24V VREF enables regulation of outputs down to 2.7V in optocoupler-based isolated PSUs. |
| High-precision grade | ±0.2% initial tolerance (T-grade) reduces calibration burden in factory-trimmed power modules. |
| Wide temperature operation | –40°C to +125°C junction range supports under-hood automotive and industrial control applications. |
| Low dynamic impedance | 0.25Ω output impedance minimizes load-induced reference perturbation in dynamic load scenarios. |
| Lead-free & green | Fully RoHS 3 compliant with <900ppm Br/Cl and <1000ppm Sb; qualified for modern environmental compliance programs. |
Applications
| Isolated Flyback Feedback | Adjustable Linear Regulator |
|---|---|
|
Use Scenario: Secondary-side voltage sensing in 5V/12V AC/DC adapters with optocoupler-coupled primary-side controller. IC Role / Device Role / Timing Role: Shunt regulator providing precise 2.7V–18V feedback voltage to optocoupler LED, closing isolation barrier loop. Use Value: Enables <±1% output accuracy without trimming, leveraging ±0.2% VREF and <11mV temp drift over full industrial range. |
Use Scenario: Boosting output voltage and accuracy of fixed LDOs like AP1084 or AP1117 in point-of-load designs. IC Role / Device Role / Timing Role: Precision reference replacing LDO's internal bandgap; sets output via R1/R2 while retaining LDO's current limit and thermal shutdown. Use Value: Achieves 1.24V–18V programmability and ±0.2% accuracy while preserving all protection features of base regulator IC. |
| High-Current Shunt Extension | Series Pass Regulator |
|
Use Scenario: Extending shunt regulation beyond 15mA by driving external NPN transistor (e.g., ZXTP2039F) with TLV431 output. IC Role / Device Role / Timing Role: Error amplifier controlling base current of series pass transistor; TLV431 sets reference, transistor handles bulk current. Use Value: Delivers >500mA regulated output while maintaining 1.24V reference stability and low-temp-coefficient performance. |
Use Scenario: Low-dropout series regulator for battery-powered instrumentation requiring <2.5V output and minimal quiescent current. IC Role / Device Role / Timing Role: Reference element setting emitter-base voltage of PNP pass transistor; regulates output by modulating base current. Use Value: Provides 1.24V–18V adjustability with <55µA minimum cathode current, enabling ultra-low-power standby modes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLV431BFTA | ±0.5% VREF tolerance at +25°C; 6mV max drift over –40°C to +85°C | Suitable for commercial-grade power supplies where cost sensitivity outweighs ±0.2% precision need | Select when B-grade accuracy suffices and budget constraints preclude T-grade premium |
| TLVH431BIDBVR | Texas Instruments part; 1.24V VREF, ±0.5%, SO-6 package, higher 80mA cathode rating | Supports higher-current shunt applications but requires different PCB layout and thermal design | Choose only if >15mA cathode current is required and SO-6 footprint is acceptable |
Compared with TLV431BFTA, TLV431TFTA offers tighter initial tolerance and lower temperature drift - critical for automotive and industrial feedback loops - while TLVH431BIDBVR trades precision for higher current capacity and different packaging, demanding layout revision and thermal reassessment.
Availability
TLV431TFTA is available at Aetrix Electronics and suitable for isolated flyback converters, adjustable LDO augmentation, high-current shunt extensions, and series pass regulators requiring stable component supply and guaranteed long-term sourcing.
Supply support for TLV431TFTA 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 devices, with emphasis on power management, signal integrity, and protection solutions.
The TLV431 series belongs to Diodes' precision reference product line, engineered specifically for high-accuracy voltage regulation in isolated and non-isolated power supply feedback paths across industrial, computing, and automotive end equipment.
FAQ
What is the minimum cathode current required for regulation at –40°C?
The TLV431TFTA requires a minimum cathode current of 55µA across –40°C to +125°C to maintain regulation. This value is specified in the Electrical Characteristics table under IKMIN at full temperature range and determines the upper bound of the series resistor used in feedback circuits.
Can TLV431TFTA replace a standard 3.3V Zener diode directly?
No - TLV431TFTA is not a drop-in Zener replacement. It requires two external resistors to set output voltage and has three terminals (Cathode, Anode, REF). A 3.3V Zener would need a resistor divider network (e.g., R1=10kΩ, R2=15.8kΩ) to configure TLV431TFTA for 3.3V output.
Does TLV431TFTA support operation above 125°C junction temperature?
No - the absolute maximum junction temperature is +150°C, but the recommended operating ambient temperature range is –40°C to +125°C. Operation beyond +125°C ambient risks exceeding the +150°C junction limit unless thermal resistance and power dissipation are strictly controlled per the SOT23 θJA = 380°C/W spec.
How does the 0.25Ω dynamic output impedance affect stability in optocoupler feedback circuits?
The 0.25Ω typical dynamic output impedance ensures minimal voltage perturbation at the REF pin during fast load transients, preserving loop stability in optocoupler-based feedback. Combined with low 80µA minimum cathode current, it enables clean, low-noise reference generation without external buffering in most isolated PSU designs.
TLV431TFTA 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:
- Active
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 1.24V
- Voltage - Output (Max):
- 18 V
- Current - Output:
- 15 mA
- Tolerance:
- ±0.2%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 100 µA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
TLV431TFTA FAQ
1.How can I place an order for TLV431TFTA through Aetrix?
Please submit a Request for Quotation (RFQ) for TLV431TFTA 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 TLV431TFTA reliable?
The price and inventory of TLV431TFTA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TLV431TFTA is usually 5 days.
3.What payment methods are accepted for TLV431TFTA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TLV431TFTA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TLV431TFTA?
TLV431TFTA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TLV431TFTA 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 TLV431TFTA?
For technical support, including TLV431TFTA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TLV431TFTA requirements.
6.How does Aetrix verify that TLV431TFTA is sourced from the original manufacturer or authorized distributors?
All TLV431TFTA 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 TLV431TFTA meets industry standards.
7.What is the process for return or replacement of TLV431TFTA?
All TLV431TFTA units undergo pre-shipment inspection (PSI). If there is an issue with TLV431TFTA, 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 TLV431TFTA part is unused and in its original packaging.
Return procedure for TLV431TFTA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TLV431TFTA 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
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