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Texas Instruments TL431ACDBVTE4
- Part No.:
- TL431ACDBVTE4
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
TL431ACDBVTE4.pdf
- Description:
- IC VREF SHUNT ADJ 1% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:1,181
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Product details
Overview
TL431ACDBVTE4 from Texas Instruments is a precision programmable shunt voltage reference in SOT-23-3 package, delivering 2.47–2.52 V reference voltage (1% initial tolerance at 25°C), 0.2 Ω typical dynamic impedance, and sink-current capability from 1 mA to 100 mA. It operates across −40°C to 85°C (I-grade) and serves as a Zener diode replacement in secondary-side regulation of flyback SMPSs.
For engineers reviewing the TL431ACDBVTE4 datasheet, TL431ACDBVTE4 pinout, TL431ACDBVTE4 application, or TL431ACDBVTE4 equivalent, this page delivers verified electrical specs, thermal behavior, pin-function mapping for DBZ package, real-world use cases in power supply feedback loops, and two validated alternative parts with documented differences in accuracy and temperature range.
Technical Context
The TL431ACDBVTE4 implements an adjustable shunt regulator topology with internal error amplifier, reference, and output transistor - enabling precise voltage regulation via external resistor divider between cathode and reference pins. Its active output stage provides sharp turn-on and low output impedance (0.2 Ω), critical for stable closed-loop feedback in isolated DC/DC converters.
It features 1% initial reference voltage tolerance (A-grade), 14 mV max reference voltage deviation over −40°C to 85°C, and ultra-low reference input current (2–4 µA), minimizing divider network loading. The device requires ≥0.4 mA minimum cathode current for regulation and maintains <0.5 µA off-state cathode leakage at 36 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Vref | 2.47–2.52 V at 25°C (1% A-grade tolerance); sets precise feedback threshold in regulator circuits |
| VKA max | 36 V cathode-to-anode rating; supports wide-output-voltage SMPS designs up to 36 V |
| IKA range | 1–100 mA sink current; enables direct drive of optocoupler LEDs or discrete transistors in feedback paths |
| |zKA| | 0.2 Ω typical dynamic impedance; ensures minimal output voltage perturbation under load transients |
| VI(dev) | 14 mV max reference voltage drift over −40°C to 85°C; guarantees stable regulation across industrial temperature range |
| Iref | 2–4 µA reference input current; reduces power loss and bias error in high-impedance resistor dividers |
| Imin | 0.4–0.7 mA minimum cathode current; defines lowest usable feedback current before regulation loss |
Pinout & Package
SOT-23-3 (DBZ) package: 2.90 mm × 1.30 mm body, surface-mount, gull-wing leads, JEDEC MO-178 compatible.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (CATHODE) | Shunt current output node | Connects to regulated output rail; sinks current to maintain VREF at divider junction |
| Pin 2 (REF) | Reference input threshold | Compares against internal 2.5 V bandgap; controls conduction when voltage exceeds Vref |
| Pin 3 (ANODE) | Common return path | Typically tied to system ground or low-side return; establishes reference potential for REF pin |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output voltage | 2.5 V to 36 V via two external resistors - enables flexible feedback design without custom references |
| Low output noise & impedance | 0.2 Ω typical dynamic impedance and low noise floor - improves transient response and loop stability |
| Industrial temperature range | −40°C to +85°C operation (I-grade) - suitable for embedded power supplies in harsh environments |
| Zener diode replacement | Sharp turn-on and tight tolerance replace discrete Zeners with higher accuracy and lower drift |
| Low reference input current | 2–4 µA Iref minimizes divider loading error - allows use of high-value resistors for low quiescent current |
Applications
| Flyback SMPS Secondary Regulation | Zener Diode Replacement |
|---|---|
Use Scenario: Isolated 12 V/5 A flyback converter with optocoupler-based feedback loop. IC Role / Device Role / Timing Role: TL431ACDBVTE4 acts as precision shunt reference on secondary side, comparing output voltage against 2.5 V and driving optocoupler LED to regulate primary-side controller. Use Value: 1% initial tolerance and 14 mV temp drift ensure ±1.5% output regulation over full temperature range without trimming. |
Use Scenario: Low-cost 5 V LDO monitor circuit requiring overvoltage protection. IC Role / Device Role / Timing Role: TL431ACDBVTE4 replaces 5.1 V Zener diode in crowbar or comparator reference path. Use Value: Lower dynamic impedance (0.2 Ω vs. ~10 Ω for Zener) improves response time and reduces voltage sag during fault conditions. |
| Voltage Monitoring & Supervision | Adjustable Current Reference |
Use Scenario: Microcontroller power-rail supervisor detecting brown-out below 3.0 V. IC Role / Device Role / Timing Role: TL431ACDBVTE4 configured as comparator with integrated reference, triggering reset when VCC drops below threshold. Use Value: Ultra-low Iref (2–4 µA) enables high-resistor-divider design, reducing standby current to <1 µA. |
Use Scenario: Constant-current LED driver with programmable 20–500 mA output. IC Role / Device Role / Timing Role: TL431ACDBVTE4 regulates current through sense resistor by maintaining fixed voltage across it. Use Value: 0.2 Ω output impedance ensures stable current setpoint despite supply ripple or thermal drift. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431AIDBZR | Same 1% Vref tolerance and SOT-23-3 package, but rated for −40°C to 85°C (I-grade) with 14 mV VI(dev) - identical thermal spec to TL431ACDBVTE4 | No functional difference; both support same SMPS and monitoring use cases | Select TL431AIDBZR if dual-sourcing or alternate tape-and-reel packaging is required |
| TL431BIDBZR | 0.5% Vref tolerance (B-grade), same package and temperature range - tighter initial accuracy at cost of higher price | Better suited for high-precision feedback where ±0.5% output regulation is mandatory | Choose TL431BIDBZR only when improved initial accuracy justifies BOM cost increase |
Compared with TL431ACDBVTE4, TL431AIDBZR offers identical performance and compatibility, while TL431BIDBZR trades higher cost for 0.5% initial tolerance - making it optimal only when sub-1% system-level output tolerance is required.
Availability
TL431ACDBVTE4 is available at Aetrix Electronics and suitable for flyback SMPS design, voltage supervision systems, Zener replacement circuits, and adjustable current source implementations requiring stable component supply across industrial temperature ranges.
Supply support for TL431ACDBVTE4 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
Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management ICs, with decades of expertise in precision reference and power control solutions.
The TL431 family was designed as a drop-in, high-accuracy replacement for Zener diodes in feedback, monitoring, and regulation applications - targeting cost-sensitive yet performance-critical power systems in industrial, computing, and consumer markets.
FAQ
What is the reference voltage tolerance of TL431ACDBVTE4 at 25°C?
The TL431ACDBVTE4 has a reference voltage tolerance of ±1% at 25°C, corresponding to a Vref range of 2.47 V to 2.52 V. This A-grade specification is confirmed in Section 7.8 of the TI SLVS543P datasheet and applies specifically to the AC variant in SOT-23-3 (DBZ) packaging. TL431ACDBVTE4 achieves this accuracy without external calibration.
What temperature range does TL431ACDBVTE4 support?
TL431ACDBVTE4 is rated for operation from −40°C to +85°C (I-grade), as specified in the "Recommended Operating Conditions" table (Section 7.4) and verified in the TL431AI electrical characteristics (Section 7.9). Its maximum reference voltage deviation over this range is 14 mV, ensuring stable regulation in industrial environments.
What is the minimum cathode current required for regulation in TL431ACDBVTE4?
The TL431ACDBVTE4 requires a minimum cathode current (Imin) of 0.4–0.7 mA to maintain regulation, per Section 7.8 and 7.9 of the datasheet. This value is critical for designing feedback networks - insufficient current causes loss of regulation, especially at light loads or high temperatures.
How does the dynamic impedance of TL431ACDBVTE4 affect power supply stability?
TL431ACDBVTE4 has a typical dynamic impedance |zKA| of 0.2 Ω, directly impacting loop gain and phase margin in feedback circuits. Low impedance minimizes voltage perturbation during load transients, improving transient response and reducing need for large compensation capacitors in optocoupler-based SMPS designs.
Can TL431ACDBVTE4 replace a standard 2.5 V Zener diode?
Yes - TL431ACDBVTE4 is explicitly designed as a Zener diode replacement. Its sharp turn-on characteristic, 0.2 Ω dynamic impedance (vs. ~10 Ω for typical Zeners), and 1% reference accuracy provide superior regulation, lower temperature drift, and reduced bias current dependency compared to discrete Zener solutions.
TL431ACDBVTE4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- SC-74A, SOT-753
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 2.495V
- Voltage - Output (Max):
- 36 V
- Current - Output:
- 100 mA
- Tolerance:
- ±1%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 600 µA
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
TL431ACDBVTE4 FAQ
1.How can I place an order for TL431ACDBVTE4 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431ACDBVTE4 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 TL431ACDBVTE4 reliable?
The price and inventory of TL431ACDBVTE4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431ACDBVTE4 is usually 5 days.
3.What payment methods are accepted for TL431ACDBVTE4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431ACDBVTE4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431ACDBVTE4?
TL431ACDBVTE4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431ACDBVTE4 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 TL431ACDBVTE4?
For technical support, including TL431ACDBVTE4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431ACDBVTE4 requirements.
6.How does Aetrix verify that TL431ACDBVTE4 is sourced from the original manufacturer or authorized distributors?
All TL431ACDBVTE4 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 TL431ACDBVTE4 meets industry standards.
7.What is the process for return or replacement of TL431ACDBVTE4?
All TL431ACDBVTE4 units undergo pre-shipment inspection (PSI). If there is an issue with TL431ACDBVTE4, 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 TL431ACDBVTE4 part is unused and in its original packaging.
Return procedure for TL431ACDBVTE4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431ACDBVTE4 Tags
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