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Texas Instruments TL431LIAEDBZRQ1
- Part No.:
- TL431LIAEDBZRQ1
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TL431LIAEDBZRQ1.pdf
- Description:
- IC VREF SHUNT ADJ 1% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:31,127
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Product details
Overview
TL431LIAEDBZRQ1 from Texas Instruments is an AEC-Q100 Grade 0 automotive-grade programmable shunt regulator with 1% initial reference voltage tolerance at 25°C, 2.495 V nominal Vref, 0.3 Ω typical dynamic impedance, and –40°C to +150°C operating ambient temperature range. It functions as a precision voltage reference and error amplifier in feedback loops for DC/DC converters, LED current sinks, and on-board chargers.
For engineers reviewing the TL431LIAEDBZRQ1 datasheet, TL431LIAEDBZRQ1 pinout, TL431LIAEDBZRQ1 application, or TL431LIAEDBZRQ1 equivalent, key selection considerations include its optimized reference input current (Iref ≤ 0.4 µA), low temperature drift (≤34 mV over full range), sink-current capability (0.6–15 mA), and SOT-23-3 DBZ package compatibility with space-constrained automotive power systems.
Technical Context
The TL431LIAEDBZRQ1 integrates a precision 2.495 V bandgap reference and high-gain op-amp in a three-terminal shunt topology, enabling adjustable output regulation from Vref to 36 V via external resistive dividers. Its Darlington output stage delivers up to 15 mA cathode sink current with sharp turn-on characteristics.
Operating in closed-loop mode, it functions as an error amplifier comparing REF pin voltage to internal reference; in open-loop mode, it serves as a comparator with integrated reference. It requires ≥0.6 mA cathode current (IKA) for regulation and is internally compensated for stability without output capacitance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Vref (25°C) | 2.495 V nominal; ±1% initial tolerance (A grade) ensures accurate setpoint for feedback networks |
| VKA Range | 2.495 V to 36 V; supports wide-range output adjustment in isolated and non-isolated converters |
| IKA Range | 0.6 mA to 15 mA; defines minimum bias and maximum load current for stable regulation |
| Dynamic Impedance | 0.3 Ω typical; minimizes output voltage variation under load transients |
| Temp Drift (Grade 0) | ≤34 mV over –40°C to +150°C; enables high-accuracy regulation in engine bay and powertrain applications |
| Iref (max) | 0.4 µA at 25°C; reduces resistor-divider error and leakage impact in high-impedance feedback paths |
| II(dev) | ≤0.3 µA over full temperature range; maintains consistent reference bias across automotive thermal cycles |
Pinout & Package
SOT-23-3 (DBZ) package, 2.90 mm × 1.30 mm body size, surface-mount compatible with automated assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Shunt current output / voltage sense node | Sinks regulated current to ANODE; voltage at this pin is controlled by REF–ANODE feedback loop |
| REF (Pin 2) | Reference input / feedback sensing node | Compares external voltage divider output to internal 2.495 V reference; must receive ≥0.4 µA bias current |
| ANODE (Pin 3) | Common return / ground reference | Establishes 0 V reference for both REF and CATHODE; all voltages defined relative to this terminal |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q100 Grade 0 qualification | Validated for –40°C to +150°C ambient operation in safety-critical powertrain and chassis systems |
| Optimized Iref and II(dev) | 0.4 µA max Iref and 0.3 µA max deviation enable higher system accuracy vs. legacy TL431-Q1 |
| Low dynamic impedance | 0.3 Ω typical ensures minimal output voltage shift during load steps in precision regulators |
| Internal compensation | Stable operation without external capacitor simplifies layout and improves reliability in EMI-sensitive environments |
| Pin-to-pin alternative to TL431-Q1 | Direct drop-in replacement in existing SOT-23-3 designs with improved thermal and leakage performance |
Applications
| DC/DC Converter Feedback | LED Lighting Current Sink |
|---|---|
Use Scenario: Secondary-side voltage regulation in isolated flyback converters using optocoupler feedback. IC Role / Device Role / Timing Role: Error amplifier comparing sampled output voltage to 2.495 V reference; drives optocoupler LED to adjust primary-side controller duty cycle. Use Value: 1% Vref tolerance and ≤34 mV temp drift maintain ±1.5% output regulation across automotive temperature extremes. | Use Scenario: Constant-current driver for automotive exterior lighting (headlamps, DRLs) with thermal derating. IC Role / Device Role / Timing Role: Precision shunt reference controlling base drive of external BJT/MOSFET pass element to regulate LED string current. Use Value: 0.4 µA max Iref minimizes sense-resistor error; 0.3 Ω dynamic impedance ensures stable current under PWM dimming transients. |
| On-Board Charger (OBC) Auxiliary Supply | Engine Management Actuator Control |
Use Scenario: Regulated auxiliary bias supply for gate drivers and controllers in 3.3 kW–22 kW bidirectional OBCs. IC Role / Device Role / Timing Role: Adjustable shunt regulator setting 12 V or 15 V rail from high-voltage DC link via resistive divider. Use Value: 36 V VKA rating and 15 mA sink capability support direct regulation from 400 V DC link with minimal external components. | Use Scenario: Closed-loop current control for solenoid actuators in variable valve timing (VVT) and fuel injector drivers. IC Role / Device Role / Timing Role: Reference element in current-sense amplifier feedback path ensuring precise coil current profiling. Use Value: Grade 0 temperature rating guarantees stable 2.495 V reference under hood temperatures up to 150°C ambient. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431LIBEDBZRQ1 | 0.5% Vref tolerance (B grade) vs. 1% (A grade); otherwise identical electrical specs and pinout | Better accuracy required for high-end ADAS power rails or precision sensor biasing | Select when tighter initial Vref tolerance justifies cost premium; same PCB layout and thermal design |
| TL432LIAEDBZRQ1 | Identical electrical specifications but reversed REF/CATHODE pinout in DBZ package (REF=Pin1, CATHODE=Pin2) | Requires PCB layout revision; used where alternate pinout eases routing in dense power sections | Choose only if board redesign is acceptable; not a drop-in replacement due to pin swap |
Compared with TL431LIBEDBZRQ1, the TL431LIAEDBZRQ1 trades 0.5% Vref accuracy for lower cost and sufficient precision for most OBC, lighting, and actuator supplies; versus TL432LIAEDBZRQ1, it retains standard pinout compatibility but cannot be substituted without layout changes.
Availability
TL431LIAEDBZRQ1 is available at Aetrix Electronics and suitable for automotive power conversion, LED lighting control, and engine management systems requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TL431LIAEDBZRQ1 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 for automotive, industrial, personal electronics, and communications markets.
The TL43xLI-Q1 product line delivers AEC-Q100 qualified shunt regulators optimized for high-accuracy, low-drift voltage reference and error amplification in automotive power systems including inverters, OBCs, and actuator controls.
FAQ
What is the maximum cathode voltage rating for TL431LIAEDBZRQ1?
The TL431LIAEDBZRQ1 has an absolute maximum cathode-to-anode voltage (VKA) rating of 37 V, with recommended operating range from Vref (2.495 V) to 36 V. This allows direct regulation from common automotive DC link voltages up to 36 V while maintaining margin against transient overvoltage events per ISO 7637-2.
Does TL431LIAEDBZRQ1 require an external capacitor for stability?
No, TL431LIAEDBZRQ1 is internally compensated and operates stably without an external capacitor between CATHODE and ANODE. However, if an output capacitor is added for noise filtering, Figure 12 in the datasheet provides stability boundary guidance based on load capacitance and cathode current to prevent oscillation.
How does the Grade 0 temperature rating affect TL431LIAEDBZRQ1 usage in engine compartments?
The Grade 0 rating certifies TL431LIAEDBZRQ1 for continuous operation from –40°C to +150°C ambient temperature, making it suitable for placement near engines, transmissions, or power electronics where case temperatures exceed 125°C. Its ≤34 mV total reference voltage drift over this range ensures regulation accuracy remains within specification without derating.
Can TL431LIAEDBZRQ1 replace standard TL431-Q1 in existing designs?
Yes, TL431LIAEDBZRQ1 is specified as a pin-to-pin alternative to TL431-Q1 in the DBZ package, with identical pinout and footprint. It offers improved Iref (≤0.4 µA vs. typical 1–2 µA) and II(dev) performance, enabling higher system accuracy and lower leakage-no PCB changes are required for drop-in replacement.
What is the minimum cathode current needed for regulation in TL431LIAEDBZRQ1?
The TL431LIAEDBZRQ1 requires a minimum cathode current (Imin) of 0.6 mA to enter and maintain regulation. Below this threshold, gain drops significantly, causing slow response and potential loss of regulation-designs must ensure external bias networks deliver ≥0.6 mA under all operating conditions, including light-load and cold-start scenarios.
TL431LIAEDBZRQ1 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:
- ±1%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 600 µA
- Operating Temperature:
- -40°C ~ 150°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
TL431LIAEDBZRQ1 FAQ
1.How can I place an order for TL431LIAEDBZRQ1 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431LIAEDBZRQ1 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 TL431LIAEDBZRQ1 reliable?
The price and inventory of TL431LIAEDBZRQ1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431LIAEDBZRQ1 is usually 5 days.
3.What payment methods are accepted for TL431LIAEDBZRQ1?
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4.How is shipping managed for TL431LIAEDBZRQ1?
TL431LIAEDBZRQ1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431LIAEDBZRQ1 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 TL431LIAEDBZRQ1?
For technical support, including TL431LIAEDBZRQ1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431LIAEDBZRQ1 requirements.
6.How does Aetrix verify that TL431LIAEDBZRQ1 is sourced from the original manufacturer or authorized distributors?
All TL431LIAEDBZRQ1 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 TL431LIAEDBZRQ1 meets industry standards.
7.What is the process for return or replacement of TL431LIAEDBZRQ1?
All TL431LIAEDBZRQ1 units undergo pre-shipment inspection (PSI). If there is an issue with TL431LIAEDBZRQ1, 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 TL431LIAEDBZRQ1 part is unused and in its original packaging.
Return procedure for TL431LIAEDBZRQ1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431LIAEDBZRQ1 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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