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Texas Instruments TL431LIBQDBZRQ1
- Part No.:
- TL431LIBQDBZRQ1
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TL431LIBQDBZRQ1.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:39,782
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Product details
Overview
TL431LIBQDBZRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive-grade programmable shunt regulator in SOT-23 (DBZ) package, featuring 0.5% initial reference voltage tolerance at 25°C, 2.495 V nominal Vref, 0.3 Ω typical dynamic impedance, and sink-current capability up to 15 mA. It serves as a precision voltage reference and error amplifier in feedback loops for DC/DC converters and LED current regulation.
For engineers reviewing the TL431LIBQDBZRQ1 datasheet, TL431LIBQDBZRQ1 pinout, TL431LIBQDBZRQ1 application, or TL431LIBQDBZRQ1 equivalent, key selection considerations include its optimized reference input current (Iref ≤ 0.4 µA), low temperature drift (≤27 mV over –40°C to +125°C), pin-to-pin compatibility with TL431-Q1, and automotive qualification for powertrain and infotainment systems.
Technical Context
The TL431LIBQDBZRQ1 integrates a precision 2.495 V bandgap reference and high-gain op-amp driving a Darlington output stage, enabling sharp turn-on and stable shunt regulation from Vref to 36 V. Its internal architecture supports both open-loop comparator operation and closed-loop error amplification via external resistor networks.
It operates with cathode current IKA from 0.6 mA to 15 mA, requires no external compensation capacitor, and maintains <0.3 µA reference input current deviation (II(dev)) across temperature - critical for high-accuracy feedback in automotive DC/DC and OBC applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Vref (25°C) | 2.495 V ±0.5% - sets precise regulation threshold for feedback networks |
| IKA Range | 0.6 mA to 15 mA - defines minimum bias and maximum sink capability for stable regulation |
| |ZKA| (Dynamic Impedance) | 0.3 Ω typical - ensures minimal output voltage variation under load transients |
| Iref (Max) | 0.4 µA - enables high-impedance sensing with negligible divider loading error |
| VI(dev) (Temp Drift) | ≤27 mV (–40°C to +125°C) - guarantees stable reference across full Grade 1 automotive range |
| VKA Max | 36 V - supports wide-input voltage regulation in 12 V/48 V automotive systems |
| Package | SOT-23 (DBZ), 2.90 mm × 1.30 mm - surface-mount compatible with high-density PCB layouts |
Pinout & Package
SOT-23 (DBZ) package: 3-pin, single-ended, moisture-sensitive level 1 (MSL-1), RoHS-compliant, rated for –40°C to +125°C ambient operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Shunt current output / voltage sense node | Connects to regulated rail; sinks current to maintain VKA = Vref × (1 + R1/R2) |
| REF (Pin 2) | Reference input / feedback node | High-impedance input (Iref ≤ 0.4 µA); ties to resistor divider midpoint for adjustable output |
| ANODE (Pin 3) | Common return / ground reference | System ground connection; all voltages referenced to this terminal |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q100 Grade 1 qualified | Validated for –40°C to +125°C ambient operation in safety-critical automotive subsystems |
| Optimized Iref and II(dev) | 0.4 µA max Iref and 0.3 µA max II(dev) reduce resistor-divider error and improve system accuracy |
| Pin-to-pin replacement for TL431-Q1 | Direct drop-in upgrade with identical DBZ footprint and electrical interface |
| Stable without output capacitor | Internally compensated for >15 mA load step response - eliminates need for external stability capacitor |
| Low dynamic impedance | 0.3 Ω typical |ZKA| minimizes output voltage droop during transient load changes |
Applications
| DC/DC Converter Feedback | LED Current Sink Regulation |
|---|---|
Use Scenario: Secondary-side voltage regulation in isolated flyback converters using optocoupler feedback. IC Role / Device Role / Timing Role: Precision shunt reference and error amplifier comparing sensed output to internal 2.495 V reference. Use Value: Enables ±0.5% output regulation accuracy with minimal component count and no external compensation. | Use Scenario: Constant-current driver for automotive interior lighting and display backlighting. IC Role / Device Role / Timing Role: Reference-controlled current sink regulating LED string current via external sense resistor. Use Value: Delivers stable 100 mA LED current with <1% total error across temperature, leveraging 0.3 Ω dynamic impedance. |
| On-Board Charger (OBC) Voltage Monitor | Engine Management Actuator Control |
Use Scenario: Overvoltage protection and reference monitoring in bidirectional AC/DC stages of EV on-board chargers. IC Role / Device Role / Timing Role: Adjustable shunt clamp setting trip point at 400 V DC bus using high-voltage resistor divider. Use Value: Provides fail-safe clamping with 27 mV max VI(dev), ensuring consistent threshold across –40°C to +125°C. | Use Scenario: Closed-loop current control for solenoid-based fuel injectors and EGR valves. IC Role / Device Role / Timing Role: Error amplifier comparing sensed actuator current to reference, driving external MOSFET gate. Use Value: Achieves <2% current accuracy over lifetime due to low Iref drift and tight Vref tolerance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BQDBZRQ1 | Same SOT-23 package and 0.5% Vref tolerance, but higher Iref (1 µA max) and VI(dev) (45 mV) | Less suitable for high-impedance dividers or extended temperature stability requirements | Select when cost sensitivity outweighs precision needs and Grade 1 thermal performance is not required |
| TLVH431QDBVRQ1 | Lower Vref (1.24 V), higher Iref (1.5 µA), same Grade 1 rating, but 1.5 Ω |ZKA| and 50 mV VI(dev) | Better for low-voltage rails (<5 V); unsuitable for 24 V+ regulation or high-accuracy feedback | Choose only for sub-5 V systems where 1.24 V reference is mandatory and 0.3 Ω impedance is not critical |
Compared with TL431BQDBZRQ1 and TLVH431QDBVRQ1, the TL431LIBQDBZRQ1 delivers superior system-level accuracy in automotive power conversion due to its lower Iref, tighter VI(dev), and matched 0.3 Ω dynamic impedance - directly enabling <0.5% output regulation without calibration.
Availability
TL431LIBQDBZRQ1 is available at Aetrix Electronics and suitable for automotive powertrain control, onboard charger feedback, and LED lighting systems requiring stable component supply with AEC-Q100 compliance and long-term lifecycle support.
Supply support for TL431LIBQDBZRQ1 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 automotive, industrial, and power management ICs.
The TL43xLI-Q1 product line was designed specifically for automotive-grade precision voltage regulation and error amplification, targeting applications demanding AEC-Q100 qualification, low drift, and high reliability in harsh environments.
FAQ
What is the reference voltage tolerance of TL431LIBQDBZRQ1 at 25°C?
The TL431LIBQDBZRQ1 has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a nominal Vref of 2.495 V with a range of 2.483 V to 2.507 V. This B-grade accuracy is specified per the TI SNVSBA4A datasheet and is validated across production lots for automotive use. The TL431LIBQDBZRQ1 achieves this tolerance without trimming, making it suitable for high-volume automotive systems where calibration is impractical.
Does TL431LIBQDBZRQ1 require an external compensation capacitor?
No, the TL431LIBQDBZRQ1 is internally compensated and remains stable without an external output capacitor between cathode and anode - a key design advantage over legacy shunt regulators. This allows direct integration into feedback loops of flyback converters and current sinks without stability analysis. However, if an output capacitor is added, Figure 12 in the SNVSBA4A datasheet must be consulted to avoid oscillation in specific CL and RLOAD combinations.
What is the maximum cathode voltage rating for TL431LIBQDBZRQ1?
The absolute maximum cathode voltage (VKA) for TL431LIBQDBZRQ1 is 37 V, with recommended operating range from Vref (2.495 V) to 36 V. This 36 V upper limit enables use in 24 V automotive systems and intermediate bus regulation. Exceeding 36 V risks violating recommended conditions and may accelerate parametric shift; operation at 37 V is only allowed as a non-operational stress rating.
How does TL431LIBQDBZRQ1 differ from TL432LI-Q1 in the same DBZ package?
The TL431LIBQDBZRQ1 and TL432LI-Q1 share identical electrical specifications and AEC-Q100 qualification, but feature reversed REF and CATHODE pin assignments in the DBZ package: TL431LIBQDBZRQ1 uses Pin 1=CATHODE/Pin 2=REF, while TL432LI-Q1 uses Pin 1=REF/Pin 2=CATHODE. This pinout difference mandates PCB layout revision - they are not interchangeable without board modification.
What is the minimum cathode current required for regulation in TL431LIBQDBZRQ1?
The TL431LIBQDBZRQ1 requires a minimum cathode current (Imin) of 0.6 mA to maintain regulation, as specified in Section 7.3 of the SNVSBA4A datasheet. Below this threshold, gain drops significantly, causing slow response and potential loss of regulation. Designers must ensure external bias networks deliver ≥0.6 mA under worst-case conditions (e.g., minimum input voltage, maximum temperature) to guarantee stable operation across the full automotive temperature range.
TL431LIBQDBZRQ1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- 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:
- 15 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:
- -40°C ~ 125°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
TL431LIBQDBZRQ1 FAQ
1.How can I place an order for TL431LIBQDBZRQ1 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431LIBQDBZRQ1 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 TL431LIBQDBZRQ1 reliable?
The price and inventory of TL431LIBQDBZRQ1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431LIBQDBZRQ1 is usually 5 days.
3.What payment methods are accepted for TL431LIBQDBZRQ1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431LIBQDBZRQ1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431LIBQDBZRQ1?
TL431LIBQDBZRQ1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431LIBQDBZRQ1 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 TL431LIBQDBZRQ1?
For technical support, including TL431LIBQDBZRQ1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431LIBQDBZRQ1 requirements.
6.How does Aetrix verify that TL431LIBQDBZRQ1 is sourced from the original manufacturer or authorized distributors?
All TL431LIBQDBZRQ1 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 TL431LIBQDBZRQ1 meets industry standards.
7.What is the process for return or replacement of TL431LIBQDBZRQ1?
All TL431LIBQDBZRQ1 units undergo pre-shipment inspection (PSI). If there is an issue with TL431LIBQDBZRQ1, 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 TL431LIBQDBZRQ1 part is unused and in its original packaging.
Return procedure for TL431LIBQDBZRQ1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431LIBQDBZRQ1 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
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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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