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Texas Instruments TL431AQDBVT
- Part No.:
- TL431AQDBVT
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
TL431AQDBVT.pdf
- Description:
- IC VREF SHUNT ADJ 1% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:1,418
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Product details
Overview
TL431AQDBVT from Texas Instruments is a precision programmable shunt voltage reference in SOT-23-3 package, featuring 1% initial reference voltage tolerance at 25°C, −40°C to 125°C operating temperature range, and 0.2Ω typical dynamic impedance. It delivers stable 2.47–2.52V reference output adjustable up to 36V via external resistors and is widely used in industrial AC/DC power supplies and servo drive control modules.
For engineers reviewing the TL431AQDBVT datasheet, TL431AQDBVT pinout, TL431AQDBVT application, or TL431AQDBVT equivalent, key selection criteria include automotive-grade temperature performance (−40°C to 125°C), 14–34mV reference voltage drift over full temperature range, sink-current capability from 1mA to 100mA, and SOT-23-3 footprint compatibility with board space-constrained designs.
Technical Context
The TL431AQDBVT implements a three-terminal adjustable shunt regulator architecture with an internal precision op-amp and NPN transistor output stage. Its reference input (REF) compares against an internal 2.495V bandgap-derived threshold, controlling cathode current flow to maintain regulation between REF and ANODE terminals.
It operates as a two-quadrant device: sinking current from cathode to anode when VKA exceeds Vref, with sharp turn-on characteristics enabling Zener diode replacement in feedback loops. The Q-grade qualification ensures validated performance across −40°C to 125°C, supporting automotive and industrial applications requiring high thermal stability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.47–2.52 V at 25°C (1% A-grade tolerance); sets precise feedback threshold for power supply error amplifiers. |
| Temp Range | −40°C to 125°C (Q-grade); enables use in under-hood automotive or high-ambient industrial environments. |
| Ref Voltage Drift | 14–34 mV over full temperature range; ensures <±0.14% output variation in closed-loop systems. |
| Dynamic Impedance | 0.2 Ω typical; provides low-impedance reference node critical for noise immunity in switching regulator feedback paths. |
| Sink Current Range | 1–100 mA; supports direct interface with optocoupler LEDs or discrete transistor bases without external buffering. |
| Output Noise | Low broadband noise (typ. 200 nV/√Hz @ 1 kHz); minimizes jitter in precision voltage monitoring circuits. |
| Min Cathode Current | 0.4–0.7 mA; defines lowest load required to maintain regulation-critical for ultra-low-power standby modes. |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm body size), surface-mount, lead-free, RoHS-compliant. Thermal resistance RθJA = 206°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1: Cathode | Current sink output | Connects to switched node (e.g., optocoupler anode or error amplifier output); carries full regulation current. |
| Pin 2: Anode | Common return path | Typically tied to system ground or power supply return; serves as voltage reference point for REF and Cathode. |
| Pin 3: Ref | Reference input | High-impedance (2–4 µA max) input sensing feedback divider voltage; triggers regulation when ≥2.495V relative to Anode. |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output voltage | 2.5V to 36V via two external resistors-enables single BOM part for multiple output rails. |
| Sharp turn-on characteristic | Fast response to REF threshold crossing-reduces phase lag in feedback loops of SMPS controllers. |
| Low output impedance | 0.2Ω typical-maintains stable reference under dynamic load transients in isolated flyback feedback networks. |
| Automotive temperature grade | Qualified for −40°C to 125°C operation-meets AEC-Q100 stress test requirements for under-hood use. |
| Low reference input current | 2–4 µA typical-minimizes divider resistor power loss and improves accuracy in high-impedance feedback networks. |
Applications
| Industrial AC/DC Power Supply | Rack Server Power |
|---|---|
|
Use Scenario: Secondary-side voltage regulation in isolated flyback converters delivering 12V/48V outputs. IC Role / Device Role / Timing Role: Shunt reference in optocoupler feedback loop, setting precise output voltage threshold. Use Value: 1% initial tolerance and 14–34mV temp drift ensure ±1.5% total output accuracy across temperature-meeting IEC 62368-1 hold-up and regulation specs. |
Use Scenario: Multi-rail PMBus-controlled power supplies with independent 3.3V, 5V, and 12V outputs. IC Role / Device Role / Timing Role: Precision reference for digital PWM controller ADC inputs and analog margining circuits. Use Value: Low 0.2Ω impedance prevents loading errors during fast DAC-driven voltage adjustments-enabling ±0.5% programmable margining accuracy. |
| Servo Drive Control Module | AC Inverter & VF Drives |
|
Use Scenario: Isolated gate driver bias supply and current-sense amplifier reference in motor control PCBs. IC Role / Device Role / Timing Role: Stable 2.5V reference for delta-sigma modulators and isolated ADCs measuring phase currents. Use Value: −40°C to 125°C rating ensures consistent ADC offset calibration across motor thermal cycles-reducing torque ripple below 0.3%. |
Use Scenario: DC-link voltage monitoring and overvoltage protection circuitry in 3-phase inverters (400–690V AC input). IC Role / Device Role / Timing Role: High-impedance voltage divider reference for comparator-based fault detection thresholds. Use Value: 36V max cathode voltage rating allows direct interface with scaled-down DC-link signals-eliminating need for additional level-shifting stages. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACDBVR | Same SOT-23-3 package, but C-grade (0°C to 70°C) and 1% tolerance; 4–25mV ref drift vs. 14–34mV for TL431AQDBVT. | Limited to commercial-temperature applications (e.g., consumer adapters); unsuitable for under-hood or industrial enclosures. | Select only if ambient temperature stays within 0–70°C and cost sensitivity outweighs thermal robustness. |
| TLVH431AQDBVR | Lower 1.24V reference voltage, same Q-grade temp range; higher 3–6µA reference current; 0.3Ω dynamic impedance. | Enables lower-voltage feedback designs (e.g., 1.8V/2.5V LDOs); less suitable for traditional 5V/12V SMPS due to reduced headroom. | Choose when designing sub-3V regulated rails or needing tighter low-voltage accuracy; verify loop stability with higher ZKA. |
Compared with TL431ACDBVR and TLVH431AQDBVR, TL431AQDBVT uniquely balances automotive-grade thermal range, 1% initial accuracy, and 0.2Ω impedance-making it optimal for industrial power supplies where both reliability and feedback precision are non-negotiable.
Availability
TL431AQDBVT is available at Aetrix Electronics and suitable for industrial AC/DC power supplies, servo drive control modules, and AC inverter & VF drives requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TL431AQDBVT 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 and embedded processing technologies, with decades of expertise in precision analog ICs and power management solutions.
The TL431 family was designed as a pin-compatible, adjustable shunt reference to replace discrete Zener diodes in feedback networks-targeting high-reliability power conversion, industrial control, and automotive systems.
FAQ
What is the reference voltage tolerance of TL431AQDBVT at 25°C?
The TL431AQDBVT has a 1% initial reference voltage tolerance at 25°C, corresponding to a 2.47–2.52 V range. This A-grade specification is explicitly defined in Section 6.10 of the TI SLVS543S datasheet and applies only to the Q-temp variant. It ensures predictable startup behavior and tight output regulation in feedback-critical applications like server PSUs.
Does TL431AQDBVT support operation at 125°C junction temperature?
Yes, TL431AQDBVT is qualified for continuous operation from −40°C to 125°C ambient temperature (Q-grade). Its absolute maximum junction temperature is 150°C, and thermal data shows RθJA = 206°C/W in SOT-23-3. At 100mA sink current and 5V drop, power dissipation is 0.5W-well within safe limits at 125°C ambient with standard PCB copper area.
How does the pinout of TL431AQDBVT differ from TL432AQDBVT?
TL431AQDBVT uses the standard SOT-23-3 pinout: Pin 1 = Cathode, Pin 2 = Anode, Pin 3 = Ref. TL432AQDBVT swaps Anode and Ref pins (Pin 1 = Cathode, Pin 2 = Ref, Pin 3 = Anode). This difference is documented in Table 5-1 and Figure 5-1 of the datasheet-using TL432AQDBVT in a TL431AQDBVT layout causes immediate functional failure due to reversed reference connection.
What is the minimum cathode current required for regulation in TL431AQDBVT?
The TL431AQDBVT requires a minimum cathode current of 0.4–0.7 mA to maintain regulation, per Section 6.10 electrical characteristics. This value is critical for designing feedback dividers: if the upper resistor draws too much current away from the REF pin, regulation collapses. For example, with a 12V output and 2.5V reference, Rupper must be ≤27 kΩ to guarantee ≥0.4 mA into the cathode under no-load conditions.
Can TL431AQDBVT replace a Zener diode in a linear regulator feedback network?
Yes, TL431AQDBVT is explicitly designed as a superior Zener diode replacement in linear and switching regulator feedback paths. Its active circuitry delivers sharper turn-on, lower dynamic impedance (0.2Ω vs. >10Ω for typical Zeners), and tighter voltage tolerance (1% vs. 5–10%). Unlike passive Zeners, it maintains regulation down to 0.4 mA cathode current-enabling efficient light-load performance in battery-powered systems.
TL431AQDBVT 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:
- ±1%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 700 µA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
TL431AQDBVT FAQ
1.How can I place an order for TL431AQDBVT through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431AQDBVT 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 TL431AQDBVT reliable?
The price and inventory of TL431AQDBVT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431AQDBVT is usually 5 days.
3.What payment methods are accepted for TL431AQDBVT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431AQDBVT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431AQDBVT?
TL431AQDBVT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431AQDBVT 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 TL431AQDBVT?
For technical support, including TL431AQDBVT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431AQDBVT requirements.
6.How does Aetrix verify that TL431AQDBVT is sourced from the original manufacturer or authorized distributors?
All TL431AQDBVT 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 TL431AQDBVT meets industry standards.
7.What is the process for return or replacement of TL431AQDBVT?
All TL431AQDBVT units undergo pre-shipment inspection (PSI). If there is an issue with TL431AQDBVT, 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 TL431AQDBVT part is unused and in its original packaging.
Return procedure for TL431AQDBVT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431AQDBVT Tags
-
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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