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Texas Instruments TL431CDBVRE4
- Part No.:
- TL431CDBVRE4
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
TL431CDBVRE4.pdf
- Description:
- IC VREF SHUNT ADJ 2.2% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:3,339
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Product details
Overview
TL431CDBVRE4 from Texas Instruments is a precision programmable shunt voltage reference in SOT-23-3 package, delivering 2.495 V nominal reference voltage with ±0.5% initial tolerance (B grade), 6 mV max temperature drift over 0°C to 70°C, 0.2 Ω typical dynamic impedance, and 1–100 mA sink-current capability. It serves as an adjustable voltage reference or Zener diode replacement in secondary-side regulation of flyback SMPSs.
For engineers reviewing the TL431CDBVRE4 datasheet, TL431CDBVRE4 pinout, TL431CDBVRE4 application, or TL431CDBVRE4 equivalent, this page provides verified electrical specifications, thermal behavior, real-world use cases, and validated alternative options for voltage reference design and power supply feedback loop implementation.
Technical Context
The TL431CDBVRE4 implements a three-terminal adjustable shunt regulator architecture with an internal precision op-amp and NPN transistor output stage. Its REF pin senses voltage relative to ANODE, triggering cathode current conduction when the divider ratio exceeds Vref (2.495 V), enabling precise closed-loop regulation without external error amplifiers.
It operates exclusively in shunt mode with ANODE as the common reference node, supports 2.5 V to 36 V programmable output via two external resistors, and maintains stable regulation down to 0.4 mA minimum cathode current - critical for low-power biasing and monitoring circuits.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Vref | 2.495 V nominal; sets exact threshold for feedback loop activation in adjustable supplies |
| Initial Tolerance | ±0.5% at 25°C (B grade); enables high-accuracy output setting without trimming |
| Temp Drift (VI(dev)) | 6 mV max over 0°C to 70°C; ensures ≤0.024% output variation across commercial temp range |
| Dynamic Impedance | 0.2 Ω typical; minimizes output voltage perturbation under load transients |
| Cathode Current Range | 1–100 mA; supports direct sinking into optocoupler LEDs or error amplifier inputs |
| Min Regulation Current | 0.4 mA; allows operation in ultra-low-power standby or monitoring modes |
| Off-State Leakage | 0.1 µA max at 36 V; prevents false triggering in high-impedance sensing networks |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm body), surface-mount, JEDEC-standard footprint with gull-wing leads. Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE | Shunt current output node | Carries regulated sink current; connects to SMPS feedback node or optocoupler anode |
| REF | Reference input threshold | Senses divided output voltage; conduction begins when voltage ≥2.495 V relative to ANODE |
| ANODE | Common reference and return path | Acts as circuit ground reference point; must be tied to system ground or lowest potential node |
Key Features
| Feature | Design Value |
|---|---|
| Sharp turn-on characteristic | Enables clean switching between regulation and cutoff states, reducing hysteresis in feedback loops |
| Low output noise | Supports stable regulation in sensitive analog circuits without added filtering components |
| Adjustable output (2.5–36 V) | Eliminates need for multiple fixed-voltage references; one part covers wide output range |
| −40°C to 125°C extended variants available | TL431CDBVRE4 is rated 0°C to 70°C; same pinout supports drop-in upgrade to I/Q grades if needed |
Applications
| Secondary-Side Flyback Regulation | Zener Diode Replacement |
|---|---|
Use Scenario: Isolated DC-DC converter using optocoupler-based feedback to regulate output voltage on secondary side. IC Role / Device Role / Timing Role: TL431CDBVRE4 acts as precision voltage comparator and shunt driver, sinking current into optocoupler LED when output exceeds setpoint. Use Value: Enables ±1% output accuracy across line/load/temperature without primary-side sensing or complex compensation. |
Use Scenario: Low-cost voltage clamping or reference generation in linear regulators, battery monitors, or overvoltage protection circuits. IC Role / Device Role / Timing Role: TL431CDBVRE4 replaces discrete Zener diodes with superior stability, lower impedance, and tighter tolerance. Use Value: Reduces board space and improves long-term drift performance versus 5% tolerance Zeners. |
| Voltage Monitoring | Comparator with Integrated Reference |
Use Scenario: Microcontroller supervisory circuit detecting brown-out or overvoltage conditions on 3.3 V or 5 V rails. IC Role / Device Role / Timing Role: TL431CDBVRE4 compares rail voltage against internal 2.495 V reference via resistor divider; drives open-drain alert signal. Use Value: Eliminates need for external reference IC and comparator, lowering BOM count and layout complexity. |
Use Scenario: Threshold detection in analog front-ends, such as battery charge termination or sensor trip-point logic. IC Role / Device Role / Timing Role: TL431CDBVRE4 functions as a comparator with built-in precision reference, driving external transistor or logic gate. Use Value: Provides accurate, temperature-stable switching point without calibration or trimming. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACDBVR | 1% initial tolerance (A grade) vs. 0.5% (B grade); otherwise identical specs and pinout | Suitable where ±1% output accuracy suffices; lower cost for less demanding designs | Select TL431ACDBVR when budget constraints outweigh need for highest precision |
| TLVH431IDBVR | Lower 1.24 V reference voltage; 1.5% tolerance; 1.5 V min cathode-anode voltage; different pinout (REF/ANODE/CATHODE order) | Used in low-voltage systems (<3 V); not pin-compatible; requires PCB redesign | Choose TLVH431IDBVR only for sub-2.5 V reference needs and layout flexibility |
Compared with TL431CDBVRE4, TL431ACDBVR offers cost savings at minor accuracy trade-off, while TLVH431IDBVR enables low-voltage operation but demands new layout and recalculates feedback dividers.
Availability
TL431CDBVRE4 is available at Aetrix Electronics and suitable for industrial power supplies, consumer AC-DC adapters, and automotive body electronics requiring stable component supply and long-term manufacturability.
Supply support for TL431CDBVRE4 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 technologies, with decades of experience in precision reference design.
The TL431 product line delivers highly stable, low-drift shunt references for feedback, monitoring, and regulation in power conversion and analog signal chains - engineered for reliability across commercial and industrial environments.
FAQ
What is the reference voltage tolerance of TL431CDBVRE4 at 25°C?
The TL431CDBVRE4 has a ±0.5% initial reference voltage tolerance at 25°C, corresponding to the B-grade specification. This means its Vref falls between 2.483 V and 2.507 V under standard test conditions (VKA = Vref, IKA = 10 mA), making TL431CDBVRE4 suitable for high-accuracy feedback applications where tight output regulation is required.
Can TL431CDBVRE4 replace a standard Zener diode in a voltage reference circuit?
Yes, TL431CDBVRE4 is explicitly designed as a Zener diode replacement. Unlike passive Zeners, TL431CDBVRE4 provides sharp turn-on, 0.2 Ω dynamic impedance, and ±0.5% tolerance - resulting in significantly better regulation accuracy, lower temperature drift, and improved stability under varying load conditions compared to typical 5% Zeners.
What is the operating temperature range for TL431CDBVRE4?
The TL431CDBVRE4 is characterized for operation from 0°C to 70°C (C-grade temperature range). It is not rated for extended industrial (−40°C to 85°C) or automotive (−40°C to 125°C) ranges; for those environments, TI offers TL431I or TL431Q variants in the same SOT-23-3 package.
How does the TL431CDBVRE4 pinout differ from TL432 devices?
TL431CDBVRE4 uses the standard TL431 pinout in SOT-23-3: Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE. TL432 devices have reversed pinout (Pin 1 = CATHODE, Pin 2 = ANODE, Pin 3 = REF), so TL431CDBVRE4 is not interchangeable with TL432DBVR without PCB modification.
What is the minimum cathode current required for TL431CDBVRE4 to maintain regulation?
The TL431CDBVRE4 requires a minimum cathode current of 0.4 mA to sustain regulation. Below this threshold, the device exits active regulation and behaves like an open circuit. This value is critical when designing high-impedance feedback dividers or low-power monitoring circuits where leakage paths may reduce available current.
TL431CDBVRE4 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:
- ±2.2%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 1 mA
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
TL431CDBVRE4 FAQ
1.How can I place an order for TL431CDBVRE4 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431CDBVRE4 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 TL431CDBVRE4 reliable?
The price and inventory of TL431CDBVRE4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431CDBVRE4 is usually 5 days.
3.What payment methods are accepted for TL431CDBVRE4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431CDBVRE4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431CDBVRE4?
TL431CDBVRE4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431CDBVRE4 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 TL431CDBVRE4?
For technical support, including TL431CDBVRE4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431CDBVRE4 requirements.
6.How does Aetrix verify that TL431CDBVRE4 is sourced from the original manufacturer or authorized distributors?
All TL431CDBVRE4 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 TL431CDBVRE4 meets industry standards.
7.What is the process for return or replacement of TL431CDBVRE4?
All TL431CDBVRE4 units undergo pre-shipment inspection (PSI). If there is an issue with TL431CDBVRE4, 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 TL431CDBVRE4 part is unused and in its original packaging.
Return procedure for TL431CDBVRE4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431CDBVRE4 Tags
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TL431AIDBZR
Texas Instruments
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TL431BQDBZR
Texas Instruments
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AN431AN-ATRG1
Diodes Incorporated
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LM4040CYM3-2.5-TR
Microchip Technology
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LM4040CYM3-4.1-TR
Microchip Technology
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LM4040EIM3-2.5/NOPB
Texas Instruments
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AZ431LBNTR-G1
Diodes Incorporated
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LM4040D20IDBZR
Texas Instruments
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LM4041DIM3-ADJ/NOPB
Texas Instruments
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LM4040DIM3X-2.5/NOPB
Texas Instruments
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LM4040DIM3-2.5/NOPB
Texas Instruments
-
AZ431LANTR-G1
Diodes Incorporated
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