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Diodes Incorporated TLV431BFTA
- Part No.:
- TLV431BFTA
- Manufacturer:
- Diodes Incorporated
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TLV431BFTA.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT23
- Quantity:
- Payment:
- Shipping:
Inventory:2,899
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Product details
Overview
TLV431BFTA from Diodes Incorporated is a precision 1.24V adjustable shunt voltage regulator in SOT23 package, rated for ±0.5% initial reference voltage tolerance at +25°C, -40°C to +125°C operating temperature, and 20mA max cathode current. It replaces Zener diodes in feedback loops of isolated DC-DC converters and low-voltage LDO supervision circuits.
For engineers reviewing the TLV431BFTA datasheet, TLV431BFTA pinout, TLV431BFTA application, or TLV431BFTA equivalent, key selection criteria include reference voltage accuracy over temperature, minimum cathode current (80µA), dynamic output impedance (0.25Ω), and compatibility with optocoupler-based secondary-side regulation in flyback and forward converters.
Technical Context
The TLV431BFTA operates as a 3-terminal shunt regulator where the REF pin senses a resistive divider voltage, 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 functions within a cathode-to-anode voltage range of 1.24V to 18V, supports continuous cathode currents from 0.1mA to 15mA under recommended conditions, and exhibits 11mV total reference deviation over –40°C to +125°C - critical for automotive and industrial power supply feedback stability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VREF | 1.24V nominal; ±0.5% tolerance at +25°C ensures tight output voltage setting in precision feedback networks |
| Temp Range | –40°C to +125°C operating ambient; enables use in under-hood automotive and industrial power supplies |
| VKA Max | 20V absolute max cathode voltage; allows direct use with 12V/15V input rails without series limiting resistor overhead |
| IKMIN | 80µA typical minimum cathode current for regulation; reduces standby power loss vs. standard Zeners requiring ≥1mA |
| ZKA | 0.25Ω typical dynamic output impedance; improves load transient response and ripple rejection in closed-loop systems |
| IREF | 0.15µA typical reference input current; minimizes divider resistor power loss and thermal drift in high-impedance feedback paths |
| VREF Drift | 11mV over –40°C to +125°C; enables <±1% output voltage variation in unbuffered isolated PSU designs |
Pinout & Package
TLV431BFTA is housed in a RoHS-compliant SOT23-3 package (JEDEC TO-236AB), with thermal resistance θJA = 380°C/W and 330mW maximum power dissipation at TA = +25°C. Pin 1 = CATHODE, Pin 2 = ANODE, Pin 3 = REFERENCE.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CATHODE) | Current sink node | Connects to supply rail via series resistor; sinks regulated current to maintain VREF at REF pin |
| 2 (ANODE) | Reference ground reference | Common return path for cathode current and feedback divider; must be tied to system ground or low-impedance return |
| 3 (REF) | Feedback sense input | High-impedance input monitoring voltage divider output; sets regulated output via R1/R2 ratio per VOUT = VREF × (1 + R1/R2) |
Key Features
| Feature | Design Value |
|---|---|
| Low-voltage reference | 1.24V VREF enables regulation down to ~2.7V output in optocoupler-coupled PSUs |
| High temp stability | 11mV total VREF deviation over –40°C to +125°C supports AEC-Q100 Grade 1–compatible designs |
| Low IREF | 0.15µA typical reference current permits >1MΩ feedback dividers, reducing quiescent power and self-heating error |
| Low ZKA | 0.25Ω output impedance maintains regulation accuracy during fast load transients in switching PSUs |
| Lead-free & green | Fully RoHS 3 compliant, halogen- and antimony-free per Diodes' "Green" definition (<900ppm Br/Cl, <1000ppm Sb) |
Applications
| Isolated Flyback PSU Feedback | Low-Voltage LDO Supervision |
|---|---|
|
Use Scenario: Secondary-side voltage regulation in 5V/3.3V isolated flyback converters using PC817 optocoupler. IC Role / Device Role / Timing Role: Shunt regulator controlling optocoupler LED current to close feedback loop across isolation barrier. Use Value: Enables ±1% output accuracy over line/load/temp without primary-side controller modification; replaces discrete Zener + transistor solutions. |
Use Scenario: Monitoring 1.8V core rail in FPGA or microcontroller power domain for reset assertion. IC Role / Device Role / Timing Role: Precision voltage threshold detector with adjustable trip point via external resistors. Use Value: Provides tighter undervoltage lockout (UVLO) than internal POR circuits; supports custom reset delay via RC on REF pin. |
| Adjustable Linear Regulator Enhancer | High-Accuracy Current Sink |
|
Use Scenario: Boosting output voltage and accuracy of AP1117 fixed 3.3V LDO to 5.0V ±0.5%. IC Role / Device Role / Timing Role: Programmable reference replacing ADJ pin voltage in adjustable linear regulators. Use Value: Leverages AP1117's built-in current limit and thermal shutdown while achieving higher output voltage and tighter tolerance. |
Use Scenario: Constant-current bias for laser diodes or LED strings in optical modules. IC Role / Device Role / Timing Role: Precision shunt-controlled current source using REF pin as virtual ground. Use Value: Delivers <±0.5% current accuracy over temperature with <100ppm/°C drift - superior to op-amp-based sinks. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLV431AFTA | ±1% VREF tolerance at +25°C; 12mV VREF drift over –40°C to +125°C | Suitable for cost-sensitive consumer PSUs where ±2% output tolerance is acceptable | Select when B-grade accuracy is unnecessary and bill-of-materials cost reduction is prioritized |
| TLV431TFTA | ±0.2% VREF tolerance at +25°C; 8mV VREF drift over –40°C to +125°C | Required for automotive body control modules needing AEC-Q100-compliant voltage references | Choose when system-level output accuracy demands <±0.75% over full temperature range |
Compared with TLV431AFTA, TLV431BFTA delivers 2× tighter initial tolerance and lower temperature drift - enabling higher output accuracy without increasing feedback resistor precision; versus TLV431TFTA, it trades 2.5× tighter tolerance for lower unit cost and broader availability in high-volume production.
Availability
TLV431BFTA is available at Aetrix Electronics and suitable for isolated DC-DC converter feedback, low-voltage supervisor circuits, and adjustable LDO enhancement applications requiring stable component supply and guaranteed long-term sourcing.
Supply support for TLV431BFTA 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, specializing in power management, signal integrity, and protection solutions for industrial, computing, and automotive markets.
The TLV431BFTA belongs to Diodes' precision shunt regulator product line, designed specifically to replace Zener diodes in high-accuracy, low-power feedback and voltage-monitoring applications across harsh-temperature environments.
FAQ
What is the minimum cathode current required for regulation in TLV431BFTA?
The TLV431BFTA requires a minimum cathode current (IKMIN) of 80µA at –40°C to +125°C to maintain regulation. This value is confirmed in the Electrical Characteristics table under "IKMIN Minimum Cathode Current for Regulation" at full temperature range. Below this current, the device may not sustain stable reference voltage.
Can TLV431BFTA be used in place of a Zener diode in a simple voltage clamp circuit?
Yes - TLV431BFTA can directly replace Zener diodes in clamp or reference applications, but requires a minimum 80µA cathode current and proper connection of ANODE to ground. Unlike Zeners, its REF pin must be driven by a resistive divider or controlled voltage; floating REF will disable regulation.
Does TLV431BFTA support operation above 125°C junction temperature?
No - the absolute maximum junction temperature is +150°C, but the recommended operating ambient temperature range is strictly –40°C to +125°C. Operation beyond +125°C ambient risks exceeding TJ(max) unless thermal design ensures θJA × PD + TA ≤ 150°C, which is not guaranteed per datasheet specifications.
How does the SOT23 package of TLV431BFTA affect thermal performance in high-current applications?
The SOT23 package has θJA = 380°C/W and 330mW maximum power dissipation at TA = +25°C. At 15mA cathode current and 12V VKA, power dissipation reaches 180mW - well within limits. However, PCB copper area and airflow become critical above 100mW to avoid derating; thermal vias under pin 2 (ANODE) improve heat transfer.
TLV431BFTA 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:
- ±0.5%
- 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
TLV431BFTA FAQ
1.How can I place an order for TLV431BFTA through Aetrix?
Please submit a Request for Quotation (RFQ) for TLV431BFTA 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 TLV431BFTA reliable?
The price and inventory of TLV431BFTA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TLV431BFTA is usually 5 days.
3.What payment methods are accepted for TLV431BFTA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TLV431BFTA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TLV431BFTA?
TLV431BFTA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TLV431BFTA 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 TLV431BFTA?
For technical support, including TLV431BFTA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TLV431BFTA requirements.
6.How does Aetrix verify that TLV431BFTA is sourced from the original manufacturer or authorized distributors?
All TLV431BFTA 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 TLV431BFTA meets industry standards.
7.What is the process for return or replacement of TLV431BFTA?
All TLV431BFTA units undergo pre-shipment inspection (PSI). If there is an issue with TLV431BFTA, 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 TLV431BFTA part is unused and in its original packaging.
Return procedure for TLV431BFTA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TLV431BFTA Tags
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TL431BQDBZR
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