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Texas Instruments TLV431BQDBVT
- Part No.:
- TLV431BQDBVT
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
TLV431BQDBVT.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:664
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Product details
Overview
TLV431BQDBVT from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, ±0.5% initial tolerance at 25°C, and operation down to 1.24 V cathode-anode voltage. It delivers 0.25 Ω typical dynamic impedance and supports adjustable output from 1.24 V to 6 V using two external resistors. It serves as a Zener replacement and error amplifier in isolated flyback SMPS feedback loops.
For engineers reviewing the TLV431BQDBVT datasheet, TLV431BQDBVT pinout, TLV431BQDBVT application, or TLV431BQDBVT equivalent, key selection considerations include its 0.5% reference accuracy, ultra-small SC-70 (DCK) package, 80 µA typical cathode current requirement, –40°C to 125°C Q-grade temperature range, and compatibility with optocoupler-based secondary-side regulation.
Technical Context
The TLV431BQDBVT implements a bandgap-referenced error amplifier driving an internal Darlington sink transistor. Its closed-loop operation enables precise shunt regulation by comparing external resistor-divided cathode voltage against the 1.24 V internal reference, while open-loop use provides comparator functionality with integrated reference.
It operates with ≥1.24 V cathode-to-anode headroom and requires ≥55 µA minimum cathode current for regulation across its full –40°C to 125°C operating range. The device is internally compensated and stable without an output capacitor, though capacitive load stability depends on voltage and frequency per Figure 5-19–5-21.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 1.24 V nominal, ±0.5% tolerance at 25°C - sets precise regulation point for external resistor network |
| Adjustable Output Range | 1.24 V to 6 V - enables flexible voltage setting in feedback paths without external reference |
| Operating Temperature | –40°C to +125°C - qualified for automotive and industrial environments requiring extended thermal range |
| Dynamic Impedance | 0.25 Ω typical - ensures tight regulation under varying load conditions in shunt configurations |
| Min Cathode Current | 55 µA (typ), ≤100 µA (max) - enables low-power operation in battery-backed or energy-sensitive designs |
| Output Noise | 35 µVRMS (10 Hz–10 kHz) - supports precision sensing and low-noise analog monitoring applications |
| ESD Rating | ±2000 V HBM - meets standard handling requirements for automated assembly and board-level integration |
Pinout & Package
TLV431BQDBVT is housed in an ultra-small SC-70 (DCK) package measuring 2.0 mm × 1.5 mm - 40% smaller than SOT-23-3 - with 6 pins and a substrate-connected pin requiring connection to ANODE or left open.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Shunt current input/output | Sinks regulated current; connects to feedback node or optocoupler LED anode in isolated supplies |
| REF (Pin 3) | Reference input | Connects to resistor divider midpoint; must receive ≥0.1 µA bias current for proper amplifier operation |
| ANODE (Pin 6) | Common return path | Typically grounded; forms reference potential for cathode and REF terminals |
| NC (Pins 4, 5) | No internal connection | Not bonded; must remain unconnected to avoid parasitic coupling or layout interference |
| Substrate (Pin 2) | Die attachment pad | Must be connected to ANODE or left floating - not tied to PCB ground or signal planes |
Key Features
| Feature | Design Value |
|---|---|
| 0.5% reference accuracy | Enables high-precision voltage setpoints in power supply feedback without trimming or calibration |
| SC-70 (DCK) package | Reduces PCB footprint by 40% vs SOT-23-3 - critical for space-constrained portable and automotive modules |
| 1.24 V minimum operating voltage | Supports regulation in 1.8 V, 2.5 V, and 3.3 V systems where legacy TL431 (2.5 V) cannot operate |
| Internal compensation | Eliminates need for external compensation capacitor - simplifies design and improves reliability in SMPS feedback |
| Comparator mode capability | Provides integrated reference + high-gain comparison in single device - replaces discrete op-amp + Zener combos |
Applications
| Isolated Flyback SMPS Regulation | Zener Diode Replacement |
|---|---|
|
Use Scenario: Secondary-side voltage sensing in 3.3 V isolated DC/DC converters using optocoupler feedback. IC Role / Device Role / Timing Role: Adjustable shunt regulator and error amplifier - compares divided output voltage against internal 1.24 V reference to control optocoupler LED current. Use Value: Enables stable regulation down to 2.7 V output (1.24 V + opto VF) with <±0.5% setpoint accuracy and no external reference IC. |
Use Scenario: On-board voltage clamping and reference generation in low-voltage microcontroller power domains. IC Role / Device Role / Timing Role: Precision programmable shunt - replaces discrete Zener diodes with tighter tolerance, lower dynamic impedance, and wider voltage adjustability. Use Value: Reduces BOM count and improves long-term stability: 0.25 Ω impedance vs >10 Ω for typical Zeners, with <11 mV drift over –40°C to 125°C. |
| Voltage Monitoring Circuit | Comparator with Integrated Reference |
|
Use Scenario: Overvoltage/undervoltage detection in battery management systems for Li-ion cells (2.5–4.2 V range). IC Role / Device Role / Timing Role: Threshold detector - REF pin biased via resistor divider; CATHODE pulled high when input exceeds trip point. Use Value: Eliminates need for separate reference and comparator ICs; trip point accuracy defined by 0.5% VREF, not external resistor tolerance alone. |
Use Scenario: Logic-level threshold detection in sensor interface circuits with 3.3 V supply and 1.8 V logic inputs. IC Role / Device Role / Timing Role: Open-loop comparator - uses internal 1.24 V reference to compare analog input against fixed threshold. Use Value: Delivers fast response with built-in reference; output swings rail-to-rail (open-collector), enabling direct interfacing with MCU GPIO or level-shifting networks. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLV431BIDBVR | SOT-23-3 (DBZ) package; same 0.5% accuracy and –40°C to 85°C I-grade temp range | Larger footprint (2.92 mm × 2.37 mm); lacks substrate pin; lower thermal resistance (RθJA = 206°C/W vs 87°C/W) | Select when board space allows larger package and I-grade (–40°C to 85°C) suffices instead of Q-grade |
| TLVH431BQDBVR | Wider cathode-anode voltage range (1.24 V to 18 V); higher max cathode current (80 mA vs 15 mA); SOT-23-3 | Supports higher-output SMPS and industrial 24 V systems; not drop-in due to different pinout and voltage rating | Choose when >6 V regulation or >15 mA cathode current is required; verify feedback resistor recalculations |
Compared with TLV431BQDBVT, TLV431BIDBVR trades Q-grade temperature range and SC-70 size for simpler 3-pin layout, while TLVH431BQDBVR extends voltage and current capability at the cost of pin compatibility and increased quiescent current - both require circuit redesign, not direct substitution.
Availability
TLV431BQDBVT is available at Aetrix Electronics and suitable for automotive power management, industrial isolated DC/DC converters, and battery monitoring systems requiring stable component supply with guaranteed Q-grade qualification and long-term lifecycle support.
Supply support for TLV431BQDBVT 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 delivering analog and embedded processing solutions, with leadership in precision analog, power management, and signal chain technologies.
The TLV431 family was designed specifically for low-voltage, high-accuracy shunt regulation and integrated reference applications - targeting space- and power-constrained systems where legacy TL431 devices cannot operate below 2.5 V.
FAQ
What is the maximum cathode voltage rating for TLV431BQDBVT?
The absolute maximum cathode-to-anode voltage (VKA) for TLV431BQDBVT is 7 V, as specified in Section 5.1 of the datasheet. Exceeding this rating may cause permanent damage. For reliable operation, the recommended maximum is 6 V under normal conditions, aligning with its adjustable output range limit and ensuring margin for transients and ripple.
Does TLV431BQDBVT require an external capacitor for stability?
No, TLV431BQDBVT is internally compensated and remains stable without an output capacitor between CATHODE and ANODE. However, if a capacitive load is added, stability depends on voltage and capacitance value - Figures 5-19 through 5-21 in the datasheet provide phase-margin guidance for selecting appropriate capacitor values to maintain stability across operating conditions.
How does the substrate pin (Pin 2) on TLV431BQDBVT affect layout?
Pin 2 on TLV431BQDBVT is the substrate connection and must either be connected directly to the ANODE net or left electrically floating - it must never be tied to PCB ground or other signal nets. Improper connection can introduce leakage paths or thermal coupling that degrades reference accuracy and long-term stability, especially in high-impedance feedback configurations.
Can TLV431BQDBVT replace TL431 in existing designs?
TLV431BQDBVT can replace TL431 only if the system operates at ≥1.24 V cathode-anode voltage and accommodates its SC-70 (6-pin) footprint and pinout. Unlike TL431's 2.5 V reference and 3-pin TO-92/SOT-23 layout, TLV431BQDBVT offers lower voltage operation, tighter tolerance, and different pin mapping - requiring schematic and layout revision, not drop-in substitution.
What is the typical reference input current (Iref) for TLV431BQDBVT?
The typical reference input current (Iref) for TLV431BQDBVT is 0.1 µA at 25°C, with a maximum of 0.5 µA across the full –40°C to 125°C temperature range. This low bias current minimizes error in high-resistance feedback dividers and supports accurate voltage setting even with >1 MΩ resistor values, reducing power loss in precision applications.
TLV431BQDBVT 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):
- 1.24V
- Voltage - Output (Max):
- 6 V
- Current - Output:
- 15 mA
- Tolerance:
- ±0.5%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 100 µA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
TLV431BQDBVT FAQ
1.How can I place an order for TLV431BQDBVT through Aetrix?
Please submit a Request for Quotation (RFQ) for TLV431BQDBVT 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 TLV431BQDBVT reliable?
The price and inventory of TLV431BQDBVT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TLV431BQDBVT is usually 5 days.
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Once your TLV431BQDBVT 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 TLV431BQDBVT?
For technical support, including TLV431BQDBVT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TLV431BQDBVT requirements.
6.How does Aetrix verify that TLV431BQDBVT is sourced from the original manufacturer or authorized distributors?
All TLV431BQDBVT 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 TLV431BQDBVT meets industry standards.
7.What is the process for return or replacement of TLV431BQDBVT?
All TLV431BQDBVT units undergo pre-shipment inspection (PSI). If there is an issue with TLV431BQDBVT, 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 TLV431BQDBVT part is unused and in its original packaging.
Return procedure for TLV431BQDBVT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TLV431BQDBVT 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
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LM4040EIM3-2.5/NOPB
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AZ431LBNTR-G1
Diodes Incorporated
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LM4040D20IDBZR
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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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