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Texas Instruments TL431BCDBVRG4
- Part No.:
- TL431BCDBVRG4
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
TL431BCDBVRG4.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:3,970
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Product details
Overview
TL431BCDBVRG4 from Texas Instruments is a precision programmable shunt voltage reference in SOT-23-3 package, featuring 0.5% initial reference voltage tolerance (2.483 V to 2.507 V at 25°C), 6 mV max reference voltage deviation over 0°C to 70°C, and 0.2 Ω typical dynamic impedance. It operates as an adjustable 2.5–36 V shunt regulator with 1–100 mA sink capability and is widely used in secondary-side regulation of flyback SMPSs.
For engineers reviewing the TL431BCDBVRG4 datasheet, TL431BCDBVRG4 pinout, TL431BCDBVRG4 application, or TL431BCDBVRG4 equivalent, this page delivers verified electrical specs, thermal behavior, real-world use cases, and validated alternative parts - all aligned to TI's production-grade SLVS543P revision P data sheet.
Technical Context
The TL431BCDBVRG4 implements a three-terminal adjustable shunt regulator architecture with an internal 2.495 V bandgap reference, error amplifier, and NPN output stage. Its sharp turn-on characteristic and low 0.2 Ω dynamic impedance enable Zener diode replacement in precision feedback loops.
It is rated for operation from 0°C to 70°C (C-grade), supports cathode voltages up to 36 V, and maintains regulation with cathode current as low as 0.4 mA. The device draws only 2–4 µA reference input current and exhibits ≤0.5 µA off-state cathode leakage at 36 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Vref tolerance | ±0.5% at 25°C (2.483–2.507 V): enables high-accuracy feedback without external trimming |
| VI(dev) | ≤6 mV over 0°C to 70°C: ensures stable reference across commercial temperature range |
| |zKA| | 0.2 Ω typical dynamic impedance: minimizes output voltage variation under load transients |
| IKA range | 1–100 mA sink current: supports direct drive of optocoupler LEDs in isolated SMPS feedback paths |
| Iref | 2–4 µA reference input current: reduces resistor-divider power loss and improves efficiency |
| Imin | 0.4–0.6 mA minimum cathode current: allows reliable regulation even at light loads |
| Ioff | ≤0.5 µA off-state cathode current at 36 V: prevents false triggering in high-voltage monitoring circuits |
Pinout & Package
SOT-23-3 (DBV) package: 2.90 mm × 1.30 mm body, surface-mount, lead-free, RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (CATHODE) | Shunt current output node | Connects to regulated output via resistor divider; sinks current to maintain reference voltage at REF |
| Pin 2 (REF) | Reference input threshold | Internal 2.495 V comparator input; tied to resistor divider midpoint to set output voltage |
| Pin 3 (ANODE) | Common return path | Typically connected to system ground or low-side return; defines voltage reference point for REF and CATHODE |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output voltage range | 2.5 V to 36 V via two external resistors: eliminates need for multiple fixed-voltage references |
| Low output noise & impedance | 0.2 Ω typical dynamic impedance + low noise: enables clean feedback in sensitive analog control loops |
| Thermal stability | 6 mV max Vref drift over 0°C–70°C: ensures <0.01%/°C effective tempco for stable long-term regulation |
| Zener replacement capability | Sharp turn-on + low impedance: matches or exceeds Zener performance while offering adjustable voltage |
| Wide operating temperature | Rated for 0°C to 70°C ambient: suitable for commercial-grade power supplies and industrial controls |
Applications
| Secondary-Side Flyback Regulation | Zener Diode Replacement |
|---|---|
Use Scenario: Isolated DC-DC converter using optocoupler feedback to regulate output voltage on secondary side. IC Role / Device Role / Timing Role: Shunt reference providing precise 2.5 V threshold to drive optocoupler LED; sets feedback loop reference point. Use Value: Enables ±1% output regulation across line/load/temperature with minimal external components and no primary-side sensing. |
Use Scenario: Low-cost voltage clamping or threshold detection in battery management or power sequencing circuits. IC Role / Device Role / Timing Role: Precision shunt regulator replacing discrete Zener diodes where tighter tolerance and lower impedance are required. Use Value: Delivers 0.5% accuracy and 0.2 Ω impedance versus typical 5% Zeners with >10 Ω impedance - reducing voltage error under varying load. |
| Voltage Monitoring | Comparator with Integrated Reference |
Use Scenario: Overvoltage protection circuit detecting when a 12 V rail exceeds 12.5 V threshold. IC Role / Device Role / Timing Role: Programmable reference input to external comparator; REF pin sets trip point via resistor divider. Use Value: Eliminates need for separate precision reference IC, reducing BOM count and layout area in safety-critical monitoring paths. |
Use Scenario: Window comparator for battery charge termination using dual thresholds derived from single TL431BCDBVRG4. IC Role / Device Role / Timing Role: Provides stable internal reference for comparator inputs; REF pin serves as accurate 2.495 V baseline. Use Value: Enables ratiometric threshold generation with matched temperature drift - improving accuracy vs. external references. |
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 0.5% Vref tolerance but rated for –40°C to 85°C (I-grade); VI(dev) = 14 mV max | Required for extended temperature industrial or automotive environments | Select TL431BIDBVR if operating ambient exceeds 70°C or requires wider thermal margin |
| TL431BCDBVT | Identical electrical specs and grade, but in tape-and-reel packaging (3,000 pcs/reel vs. 1,000 pcs/reel for DBVRG4) | No functional difference; optimized for high-volume automated assembly | Choose TL431BCDBVT for SMT production lines requiring larger reels and consistent feed reliability |
Compared with TL431BIDBVR, TL431BCDBVRG4 offers tighter temperature drift (6 mV vs. 14 mV) at lower cost for commercial-temperature designs; compared with TL431BCDBVT, it provides identical performance in smaller reel quantity for prototyping and low-volume builds.
Availability
TL431BCDBVRG4 is available at Aetrix Electronics and suitable for commercial power supplies, industrial control systems, and consumer electronics requiring stable component supply with full traceability and lifecycle support.
Supply support for TL431BCDBVRG4 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 delivering analog, embedded processing, and logic solutions with emphasis on reliability, scalability, and broad design support.
The TL431 family was designed as a precision programmable shunt reference for feedback control in switching power supplies, voltage monitors, and comparator-based circuits - targeting cost-sensitive yet accuracy-demanding applications.
FAQ
What is the reference voltage tolerance of TL431BCDBVRG4 at 25°C?
The TL431BCDBVRG4 has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a guaranteed range of 2.483 V to 2.507 V when tested at IKA = 10 mA and VKA = Vref. This B-grade specification is confirmed in Section 7.11 of the SLVS543P datasheet and distinguishes it from A-grade (±1%) and standard-grade (±2%) variants.
Does TL431BCDBVRG4 support operation above 70°C?
No - TL431BCDBVRG4 is a C-grade device characterized for 0°C to 70°C free-air temperature operation only. For operation up to 85°C or 125°C, TI offers TL431BI and TL431BQ variants respectively. Using TL431BCDBVRG4 beyond 70°C may result in unguaranteed Vref drift (VI(dev) exceeds 6 mV) and potential regulation failure.
What is the minimum cathode current required for regulation in TL431BCDBVRG4?
The TL431BCDBVRG4 requires a minimum cathode current (Imin) of 0.4 mA to maintain regulation, with a typical value of 0.6 mA. This is specified in Section 7.11 of the datasheet under recommended operating conditions and is critical for ensuring stable feedback in low-power or high-resistance divider configurations.
Can TL431BCDBVRG4 replace a Zener diode directly in existing circuits?
Yes - TL431BCDBVRG4 is explicitly designed as a Zener diode replacement. Its sharp turn-on, 0.2 Ω dynamic impedance, and adjustable 2.5–36 V output via two resistors allow drop-in substitution in most Zener-based clamp, reference, or regulation circuits - provided ANODE is grounded and the external resistor network is recalculated for desired voltage.
What is the dynamic impedance of TL431BCDBVRG4 and why does it matter?
The TL431BCDBVRG4 has a typical dynamic impedance |zKA| of 0.2 Ω, measured at f ≤1 kHz with IKA between 1 mA and 100 mA. This low value means the output voltage changes very little under cathode current transients - essential for maintaining tight regulation in switching power supply feedback loops where load steps occur rapidly.
TL431BCDBVRG4 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:
- ±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
TL431BCDBVRG4 FAQ
1.How can I place an order for TL431BCDBVRG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431BCDBVRG4 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 TL431BCDBVRG4 reliable?
The price and inventory of TL431BCDBVRG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431BCDBVRG4 is usually 5 days.
3.What payment methods are accepted for TL431BCDBVRG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431BCDBVRG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431BCDBVRG4?
TL431BCDBVRG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431BCDBVRG4 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 TL431BCDBVRG4?
For technical support, including TL431BCDBVRG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431BCDBVRG4 requirements.
6.How does Aetrix verify that TL431BCDBVRG4 is sourced from the original manufacturer or authorized distributors?
All TL431BCDBVRG4 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 TL431BCDBVRG4 meets industry standards.
7.What is the process for return or replacement of TL431BCDBVRG4?
All TL431BCDBVRG4 units undergo pre-shipment inspection (PSI). If there is an issue with TL431BCDBVRG4, 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 TL431BCDBVRG4 part is unused and in its original packaging.
Return procedure for TL431BCDBVRG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431BCDBVRG4 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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