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Texas Instruments TL431BCDBVR
- Part No.:
- TL431BCDBVR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
TL431BCDBVR.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:5,558
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Product details
Overview
TL431BCDBVR 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 −40°C to 125°C. It serves as a high-stability replacement for Zener diodes in feedback loops of isolated DC/DC converters and AC/DC power supplies.
For engineers reviewing the TL431BCDBVR datasheet, TL431BCDBVR pinout, TL431BCDBVR application, or TL431BCDBVR equivalent, key selection criteria include its B-grade accuracy, Q-temp automotive qualification, low output noise, sink-current capability up to 100 mA, and compatibility with standard resistor-divider programming for adjustable outputs from 2.495 V to 36 V.
Technical Context
The TL431BCDBVR implements a three-terminal adjustable shunt regulator architecture with an internal error amplifier, reference, and NPN pass transistor. Its sharp turn-on characteristic and active output stage enable stable regulation without external compensation in most configurations.
It operates as a two-input comparator driving a cathode-sink output: the REF pin senses voltage relative to ANODE, and the CATHODE sinks current when REF exceeds 2.495 V. The SOT-23-3 package (DBVR) uses the TL431 pinout: Pin 1 = REF, Pin 2 = CATHODE, Pin 3 = ANODE.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V ±12 mV (B grade, 25°C); enables precise feedback setpoint for power supply regulation |
| Initial Tolerance | ±0.5% at 25°C; reduces calibration burden in production and improves system accuracy without trimming |
| Temp Range | −40°C to +125°C (Q-grade); supports under-hood automotive, industrial motor drives, and server PSU applications |
| Dynamic Impedance | 0.2 Ω typical (≤1 kHz); maintains tight output regulation despite load transients in switching regulators |
| Sink Current Range | 1 mA to 100 mA; accommodates wide range of optocoupler LED drive and error amplifier interface requirements |
| Ref Input Current | 2–4 µA typical; minimizes divider resistor power loss and thermal drift in high-impedance feedback networks |
| Output Noise | Low broadband noise; critical for low-noise LDO supervision and precision ADC reference buffering |
Pinout & Package
SOT-23-3 (DBVR) package: 2.90 mm × 1.30 mm body, gull-wing leads, tape-and-reel packaging for automated assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (REF) | Reference input | Senses voltage divider output; triggers regulation when ≥2.495 V above ANODE |
| Pin 2 (CATHODE) | Current sink output | Drives optocoupler LED or error amplifier; sinks up to 100 mA to maintain REF voltage |
| Pin 3 (ANODE) | Common reference node | Typically connected to system ground or return path; defines voltage reference point for REF and CATHODE |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output range | 2.495 V to 36 V via two external resistors - enables single BOM part for multiple output voltages |
| Thermal stability | Max 34 mV deviation over −40°C to +125°C (Q-temp) - ensures consistent regulation across environmental stress |
| Low output impedance | 0.2 Ω typical - suppresses ripple coupling and improves transient response in closed-loop PSUs |
| ESD robustness | ±2000 V HBM - withstands handling and board-level ESD events without latch-up or parameter shift |
| Shunt regulator topology | No external pass transistor required - simplifies layout, reduces component count vs discrete Zener+transistor solutions |
Applications
| AC/DC Power Supply Feedback | Rack Server VRM Monitoring |
|---|---|
Use Scenario: Secondary-side voltage sensing in isolated flyback or forward converters using optocoupler feedback. IC Role / Device Role / Timing Role: Programmable shunt reference providing precise error signal to optocoupler LED driver. Use Value: Enables ±1% output regulation over line/load/temperature without secondary-side controller IC. |
Use Scenario: Overvoltage protection and margining circuitry in multi-rail server power delivery networks. IC Role / Device Role / Timing Role: Precision threshold detector comparing rail voltage against programmable reference. Use Value: Supports accurate 12 V, 5 V, and 3.3 V rail monitoring with <10 mV trip hysteresis. |
| Industrial Motor Drive Control | Automotive Body Control Module |
Use Scenario: Voltage supervision for gate driver bias rails in IGBT/SiC half-bridge inverters. IC Role / Device Role / Timing Role: Stable reference for comparator-based undervoltage lockout (UVLO) and overvoltage detection. Use Value: Guarantees reliable shutdown during brownout conditions across −40°C to +125°C ambient. |
Use Scenario: Regulated 5 V reference for microcontroller ADC and sensor signal conditioning in BCMs. IC Role / Device Role / Timing Role: Low-drift, low-noise shunt reference replacing Zener diodes in analog front-end circuits. Use Value: Maintains <0.1% ADC accuracy over lifetime and temperature without calibration. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BIDBVR | Same SOT-23-3 package and B-grade accuracy, but rated for −40°C to +85°C (I-temp), not Q-temp. | Limited to commercial/industrial environments; unsuitable for under-hood automotive use. | Select TL431BIDBVR only if operating temperature stays ≤85°C and cost sensitivity outweighs extended temp coverage. |
| TLVH431BQDBVR | Lower 1.24 V reference voltage, 0.5% tolerance, same Q-temp rating, but higher 10 µA max reference current. | Enables lower-voltage feedback designs (e.g., 1.8 V, 2.5 V rails); less suitable for >3 V outputs due to headroom constraints. | Choose TLVH431BQDBVR when designing sub-3 V regulated supplies or needing tighter low-voltage accuracy. |
Compared with TL431BIDBVR and TLVH431BQDBVR, TL431BCDBVR uniquely combines Q-temp operation, 2.495 V reference, and ultra-low 2–4 µA reference current-making it optimal for high-accuracy, high-temperature isolated power feedback where headroom and quiescent current matter.
Availability
TL431BCDBVR is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, and automotive body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TL431BCDBVR 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 company specializing in analog and embedded processing technologies, with leadership in power management, signal chain, and high-reliability components.
The TL431 family was designed as a precision programmable shunt reference for feedback control in isolated power supplies, voltage supervision, and analog signal conditioning-targeting automotive, industrial, and computing applications demanding high accuracy and thermal stability.
FAQ
What is the reference voltage tolerance of TL431BCDBVR at 25°C?
The TL431BCDBVR has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 2.495 V nominal value with a min/max range of 2.483 V to 2.507 V per the TL431BC electrical characteristics table. This B-grade accuracy is specified in Section 6.11 of the TI datasheet SLVS543S and applies exclusively to the BC variant in SOT-23-3 packaging.
Does TL431BCDBVR support operation at 125°C?
Yes, TL431BCDBVR is qualified for operation from −40°C to +125°C (Q-temp grade), as confirmed by its part number suffix "Q" and the electrical characteristics tables 6.7 and 6.13 in the TI datasheet. Its maximum junction temperature is 150°C, and thermal resistance RθJA is 206°C/W in the SOT-23-3 (DBZ/DBVR) package.
What is the pin configuration of TL431BCDBVR?
TL431BCDBVR uses the standard TL431 pinout in SOT-23-3 (DBVR) package: Pin 1 = REF, Pin 2 = CATHODE, Pin 3 = ANODE. This differs from TL432 variants, which swap CATHODE and REF pins. The pin functions are explicitly defined in Table 5-1 and Figure 5-1 of the TI datasheet SLVS543S.
Can TL431BCDBVR replace a Zener diode in feedback circuits?
Yes, TL431BCDBVR is explicitly designed as a superior replacement for Zener diodes in feedback applications. Its active regulation, 0.2 Ω dynamic impedance, sharp turn-on, and programmable output (2.495 V to 36 V) provide significantly better accuracy, temperature stability, and transient response than passive Zener solutions-especially in optocoupler-coupled SMPS feedback loops.
What is the minimum cathode current required for regulation in TL431BCDBVR?
The TL431BCDBVR requires a minimum cathode current of 0.4 mA to maintain regulation, as specified in Section 6.11 (Electrical Characteristics, TL431BC) of the TI datasheet. This Imin value ensures stable operation even with high-value feedback resistors or low-power optocouplers, and remains valid across the full −40°C to +125°C temperature range.
TL431BCDBVR 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:
- ±0.5%
- 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
TL431BCDBVR FAQ
1.How can I place an order for TL431BCDBVR through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431BCDBVR 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 TL431BCDBVR reliable?
The price and inventory of TL431BCDBVR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431BCDBVR is usually 5 days.
3.What payment methods are accepted for TL431BCDBVR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431BCDBVR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431BCDBVR?
TL431BCDBVR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431BCDBVR 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 TL431BCDBVR?
For technical support, including TL431BCDBVR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431BCDBVR requirements.
6.How does Aetrix verify that TL431BCDBVR is sourced from the original manufacturer or authorized distributors?
All TL431BCDBVR 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 TL431BCDBVR meets industry standards.
7.What is the process for return or replacement of TL431BCDBVR?
All TL431BCDBVR units undergo pre-shipment inspection (PSI). If there is an issue with TL431BCDBVR, 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 TL431BCDBVR part is unused and in its original packaging.
Return procedure for TL431BCDBVR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431BCDBVR 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
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AZ431LANTR-G1
Diodes Incorporated
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