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Texas Instruments TL431CDBVR
- Part No.:
- TL431CDBVR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
TL431CDBVR.pdf
- Description:
- IC VREF SHUNT ADJ 2.2% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:19,317
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Product details
Overview
TL431CDBVR 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 at 25°C, 0.2 Ω typical dynamic impedance, and operation across 0°C to 70°C. It enables adjustable output from 2.495 V to 36 V using two external resistors and serves as a Zener diode replacement in feedback loops of isolated DC/DC converters and notebook power adapters.
For engineers reviewing the TL431CDBVR datasheet, TL431CDBVR pinout, TL431CDBVR application, or TL431CDBVR equivalent, key selection criteria include its C-grade temperature range (0°C to 70°C), SOT-23-3 footprint compatibility, 1 mA minimum cathode current for regulation, and low 6 mV max reference voltage drift over temperature - critical for stable feedback in AC/DC and industrial power supplies.
Technical Context
The TL431CDBVR implements an internal error amplifier with a precision 2.495 V bandgap reference, comparing the REF pin voltage against Vref to control cathode current flow. Its active output stage provides sharp turn-on and low 0.2 Ω dynamic impedance, enabling fast transient response in closed-loop regulation.
Designed for shunt regulation, it sinks 1–100 mA cathode current while maintaining tight voltage accuracy; the SOT-23-3 package (2.90 mm × 1.30 mm) supports high-density PCB layouts in space-constrained power modules without requiring external compensation in most configurations.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V nominal (2.483–2.507 V for B-grade), sets precise feedback threshold in regulator loops |
| Initial Tolerance | ±0.5% at 25°C, ensures minimal calibration overhead in production power supplies |
| Temp Range | 0°C to 70°C (C-grade), suitable for commercial-grade AC/DC adapters and industrial controls |
| Dynamic Impedance | 0.2 Ω typical, maintains stable reference under load transients up to 100 mA sink current |
| Min Cathode Current | 0.4–0.6 mA, defines lowest operating point for reliable regulation in low-power standby modes |
| Ref Input Current | 2–4 µA, enables high-impedance resistor dividers without significant loading error |
| Output Noise | Low broadband noise (typ. <10 µV RMS over 0.1–10 Hz), preserves loop stability in sensitive analog feedback |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm body size, 0.95 mm height), surface-mount, lead-free, RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1: Cathode | Shunt current output node | Connects to primary-side feedback network; sinks regulated current to maintain VREF at setpoint |
| Pin 2: Anode | Common return path | Typically tied to system ground or converter output common; establishes reference potential for internal amplifier |
| Pin 3: Ref | Reference input | High-impedance input monitoring external resistor divider; triggers regulation when voltage reaches ~2.495 V |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output range | 2.495 V to 36 V via two external resistors - eliminates need for multiple fixed-voltage references |
| Sharp turn-on characteristic | Active output circuitry enables fast response to reference voltage deviations - improves transient regulation in switching supplies |
| Low temperature drift | 6 mV max deviation over 0°C to 70°C - ensures consistent feedback accuracy without thermal recalibration |
| Low output noise | Sub-10 µV RMS integrated noise (0.1–10 Hz) - prevents noise-induced jitter in precision feedback paths |
| High sink-current capability | 1–100 mA continuous cathode current - supports direct drive of optocoupler LEDs in isolated flyback controllers |
Applications
| Rack Server Power | Industrial AC/DC |
|---|---|
Use Scenario: Secondary-side voltage sensing in multi-output telecom rectifiers with remote sense lines. IC Role / Device Role / Timing Role: Precision shunt reference providing feedback to PWM controller via optocoupler. Use Value: ±0.5% initial tolerance and 6 mV temp drift ensure ±1% output regulation across line/load/temperature - meeting IEC 62368-1 hold-up requirements. | Use Scenario: Output voltage regulation in DIN-rail mounted 24 V/48 V AC/DC power supplies. IC Role / Device Role / Timing Role: Adjustable shunt reference setting output voltage via potentiometer-adjustable resistor divider. Use Value: 0.2 Ω dynamic impedance maintains regulation stability despite 10 A load steps - reducing need for large output capacitance. |
| Notebook PC Adapter | Servo Drive Control Module |
Use Scenario: Feedback path in compact 65 W GaN-based USB-C PD adapter with dual USB-PD outputs. IC Role / Device Role / Timing Role: Primary-side referenced shunt regulator driving optocoupler LED in quasi-resonant flyback topology. Use Value: SOT-23-3 footprint enables high-density layout in <20 mm² PCB area; low 4 µA max reference current minimizes divider power loss. | Use Scenario: Isolated auxiliary supply regulation for gate drivers and position encoder interfaces in servo inverters. IC Role / Device Role / Timing Role: Shunt reference stabilizing +15 V/-15 V isolated bias rails feeding IGBT gate driver ICs. Use Value: 100 mA sink capability allows direct drive of multiple optocouplers without external transistor - simplifying auxiliary supply design. |
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 (vs. 0.5% for TL431CDBVR); otherwise identical electrical specs and SOT-23-3 package | Suitable where ±1% output regulation suffices, e.g., non-critical auxiliary rails | Select TL431ACDBVR to reduce cost where tighter reference accuracy is not required for system-level performance. |
| TLVH431IDBVR | Lower 1.24 V reference voltage; 1% initial tolerance; same SOT-23-3 package and 0.2 Ω impedance | Enables lower-voltage feedback designs (e.g., 3.3 V LDOs) but requires different resistor scaling | Choose TLVH431IDBVR only when system architecture mandates sub-2.5 V reference; not drop-in compatible due to different Vref. |
Compared with TL431ACDBVR and TLVH431IDBVR, TL431CDBVR offers the tightest initial accuracy (±0.5%) within the same SOT-23-3 footprint, making it optimal for applications demanding highest output voltage stability without redesigning feedback networks.
Availability
TL431CDBVR is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, and notebook PC power adapter designs requiring stable component supply, long-term manufacturability, and consistent parametric performance across production batches.
Supply support for TL431CDBVR 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 heritage in precision reference design.
The TL431 product line was engineered specifically for high-accuracy shunt regulation in power supply feedback circuits, targeting commercial, industrial, and automotive applications where Zener diodes lack sufficient stability and precision.
FAQ
What is the reference voltage tolerance of TL431CDBVR at 25°C?
The TL431CDBVR has a ±0.5% initial reference voltage tolerance at 25°C, corresponding to a 2.483 V to 2.507 V range around the nominal 2.495 V. This B-grade accuracy is confirmed in Section 6.11 of the TI datasheet SLVS543S and applies specifically to the TL431CDBVR variant with SOT-23-3 packaging. The tolerance remains stable across its 0°C to 70°C operating range.
Does TL431CDBVR support operation beyond 70°C?
No, TL431CDBVR is rated only for 0°C to 70°C free-air temperature (C-grade specification). For extended temperature operation, TI offers TL431I variants (−40°C to 85°C) and TL431Q variants (−40°C to 125°C), but these use different part numbers and are not interchangeable with TL431CDBVR without validation. The C-grade rating is explicitly defined in TI's device nomenclature table and Section 4 of SLVS543S.
What is the minimum cathode current required for TL431CDBVR to regulate properly?
The TL431CDBVR requires a minimum cathode current of 0.4–0.6 mA to maintain regulation, as specified in Section 6.11 (TL431BC characteristics) of the datasheet. This value ensures the internal amplifier remains biased in its active region. Operating below this threshold may cause loss of regulation or increased output impedance, particularly near the lower end of its 2.495–36 V adjustment range.
Can TL431CDBVR replace a standard Zener diode in feedback circuits?
Yes, TL431CDBVR is explicitly designed as a precision replacement for Zener diodes in feedback applications. Its 0.2 Ω dynamic impedance, sharp turn-on, and ±0.5% tolerance outperform typical Zeners (which often exhibit >5% tolerance and >10 Ω impedance). The datasheet confirms this use case in Section 3 and Figure 9-1, showing direct substitution in optocoupler-driven flyback regulators.
Is TL431CDBVR pin-compatible with TL432 series devices?
No, TL431CDBVR is not pin-compatible with TL432 devices in any package, including SOT-23-3. As stated in Section 3 of SLVS543S, TL432 has a different pinout: Pin 1 = Cathode, Pin 2 = Ref, Pin 3 = Anode - whereas TL431CDBVR uses Pin 1 = Cathode, Pin 2 = Anode, Pin 3 = Ref. Interchanging them will result in incorrect or non-functional operation.
TL431CDBVR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- SC-74A, SOT-753
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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
TL431CDBVR FAQ
1.How can I place an order for TL431CDBVR through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431CDBVR 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 TL431CDBVR reliable?
The price and inventory of TL431CDBVR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431CDBVR is usually 5 days.
3.What payment methods are accepted for TL431CDBVR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431CDBVR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431CDBVR?
TL431CDBVR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431CDBVR 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 TL431CDBVR?
For technical support, including TL431CDBVR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431CDBVR requirements.
6.How does Aetrix verify that TL431CDBVR is sourced from the original manufacturer or authorized distributors?
All TL431CDBVR 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 TL431CDBVR meets industry standards.
7.What is the process for return or replacement of TL431CDBVR?
All TL431CDBVR units undergo pre-shipment inspection (PSI). If there is an issue with TL431CDBVR, 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 TL431CDBVR part is unused and in its original packaging.
Return procedure for TL431CDBVR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431CDBVR Tags
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TL431AIDBZR
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TL431BQDBZR
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AN431AN-ATRG1
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LM4040CYM3-2.5-TR
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LM4040CYM3-4.1-TR
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LM4040EIM3-2.5/NOPB
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AZ431LBNTR-G1
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LM4040D20IDBZR
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LM4041DIM3-ADJ/NOPB
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LM4040DIM3X-2.5/NOPB
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LM4040DIM3-2.5/NOPB
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AZ431LANTR-G1
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