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Texas Instruments TL431LIAQDBZRQ1
- Part No.:
- TL431LIAQDBZRQ1
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TL431LIAQDBZRQ1.pdf
- Description:
- IC VREF SHUNT ADJ 1% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:20,441
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Product details
Overview
TL431LIAQDBZRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive-grade programmable shunt regulator in SOT-23 (DBZ) package, featuring 1% initial reference voltage tolerance at 25°C, 27 mV max temperature drift over –40°C to +125°C, 0.3 Ω typical dynamic impedance, and sink-current capability up to 15 mA - used for precision voltage regulation and error amplification in DC/DC converters and on-board chargers.
For engineers reviewing the TL431LIAQDBZRQ1 datasheet, TL431LIAQDBZRQ1 pinout, TL431LIAQDBZRQ1 application, or TL431LIAQDBZRQ1 equivalent, key selection considerations include its optimized reference input current (≤0.4 µA), low IREF deviation (≤0.3 µA), adjustable output range (2.495 V to 36 V), and automotive qualification for powertrain and infotainment systems.
Technical Context
The TL431LIAQDBZRQ1 implements a three-terminal shunt topology with internal 2.495 V bandgap reference and high-gain op-amp driving a Darlington output stage. It operates in closed-loop regulation (e.g., feedback-controlled voltage clamp) or open-loop comparator mode, requiring ≥0.6 mA cathode current to maintain linear operation and stable gain.
Its thermal stability is achieved via curvature-compensated reference design, delivering ≤27 mV total VREF deviation across –40°C to +125°C ambient, and it is internally compensated for stability without external output capacitance - though capacitor selection guidelines are provided for enhanced transient response.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VREF tolerance @ 25°C | 1% (A grade) - sets baseline accuracy for voltage-setting resistor networks in feedback loops |
| VREF nominal | 2.495 V - defines minimum adjustable output voltage and reference threshold for comparator use |
| Adjustable VKA range | 2.495 V to 36 V - enables wide-range regulation using two external resistors without additional references |
| IKA max | 15 mA - determines maximum shunt current capacity and power dissipation limit (PD = VKA × IKA) |
| IREF max | 0.4 µA - minimizes resistor-divider loading error and enables high-impedance sensing in battery-sensitive designs |
| Dynamic impedance |ZKA| | 0.3 Ω typical - ensures tight regulation under load transients; critical for error amplifier loop stability |
| Temp drift (Grade 1) | 27 mV max over –40°C to +125°C - guarantees <±11 ppm/°C effective TC for high-accuracy closed-loop systems |
Pinout & Package
SOT-23 (DBZ) package: 3-pin surface-mount, 2.90 mm × 1.30 mm body size, JEDEC MO-178 compatible, rated for automotive reflow profiles.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Shunt current output / voltage sense node | Primary current-sinking terminal; connects to regulated rail or optocoupler LED anode in isolated feedback |
| REF (Pin 2) | Reference input / error-sense node | High-impedance input (≤0.4 µA) tied to resistor divider midpoint; voltage forced to VREF in regulation |
| ANODE (Pin 3) | Common return / ground reference | Low-impedance return path; must be connected to system ground or lowest potential point in shunt configuration |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q100 Grade 1 qualification | Validated for –40°C to +125°C ambient operation in engine control, OBC, and transmission modules |
| Optimized IREF and II(dev) | 0.4 µA max IREF, 0.3 µA max deviation - reduces resistor-divider error and improves system-level accuracy vs. legacy TL431-Q1 |
| Internal compensation | Stable without output capacitor - simplifies layout and eliminates ESR-dependent instability in compact automotive PCBs |
| Darlington output stage | Enables 15 mA sink current with low saturation voltage - supports direct drive of optocoupler LEDs and discrete pass devices |
| Sharp turn-on characteristic | Fast transition between off-state and regulation - essential for precision comparator and overvoltage protection applications |
Applications
| DC/DC Converter Feedback | On-Board Charger (OBC) Regulation |
|---|---|
Use Scenario: Secondary-side voltage regulation in isolated flyback or forward converters using optocoupler-coupled feedback. IC Role / Device Role / Timing Role: Precision shunt regulator providing accurate 2.495 V reference to control optocoupler LED current and thus primary-side PWM duty cycle. Use Value: Enables ±1% output voltage accuracy over temperature and line, meeting ASIL-B functional safety requirements for EV charging stages. | Use Scenario: Voltage setpoint generation and error amplification in bidirectional AC/DC and DC/DC stages of automotive OBC units. IC Role / Device Role / Timing Role: Adjustable shunt reference setting precise DC bus voltage thresholds (e.g., 400 V or 800 V rails) with feedback to isolated controller ICs. Use Value: Maintains <27 mV VREF drift across full automotive temperature range, ensuring consistent charge termination and grid synchronization. |
| Engine Management Actuator Control | Infotainment Power Sequencing |
Use Scenario: Precision current sink for solenoid or valve driver circuits requiring stable bias current independent of supply variation. IC Role / Device Role / Timing Role: Shunt-regulated constant-current source controlling gate/base drive of external MOSFET/BJT actuator switches. Use Value: Delivers 100 mA LED or solenoid current with <1% setpoint error using only RS and TL431LIAQDBZRQ1 - eliminating need for dedicated current DACs. | Use Scenario: Power-good signaling and rail sequencing in head-unit or digital cluster SoC power domains (e.g., 1.8 V, 3.3 V, 5 V). IC Role / Device Role / Timing Role: Comparator with integrated reference monitoring intermediate rail voltages and asserting reset or enable signals. Use Value: Provides fast, accurate trip points (e.g., 3.3 V ±1%) with <1 µs propagation delay - enabling deterministic multi-rail startup timing per ISO 16750-2. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431LIQDBZRQ1 | Same electrical specs, B-grade (0.5% VREF tolerance), identical pinout and package | Higher accuracy required in precision sensor biasing or reference ladder networks | Select when tighter initial tolerance justifies cost premium and thermal drift budget allows |
| TL432LIAQDBZRQ1 | Identical electrical specs and grades, but reversed REF/CATHODE pinout in DBZ package (Pin 1 = REF, Pin 2 = CATHODE) | Layout reuse in existing SOT-23 footprints where pin 1–2 swap is acceptable | Choose only if board revision permits pin-swapped placement; not drop-in replacement |
Compared with TL431LIAQDBZRQ1, the TL431LIQDBZRQ1 offers improved initial accuracy at same thermal performance, while TL432LIAQDBZRQ1 provides functional equivalence only with PCB layout modification - neither is pin-compatible without redesign.
Availability
TL431LIAQDBZRQ1 is available at Aetrix Electronics and suitable for automotive powertrain control, on-board charger feedback, and infotainment power sequencing requiring stable component supply with AEC-Q100 traceability and long-term lifecycle support.
Supply support for TL431LIAQDBZRQ1 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, embedded processing, and automotive ICs, with leadership in high-reliability power management solutions.
The TL43xLI-Q1 product line delivers AEC-Q100 qualified shunt regulators optimized for automotive subsystems demanding precision, low drift, and robustness - including engine control, battery management, and ADAS power domains.
FAQ
What is the maximum cathode voltage rating for TL431LIAQDBZRQ1?
The absolute maximum cathode-to-anode voltage (VKA) for TL431LIAQDBZRQ1 is 37 V, with recommended operating range from VREF (2.495 V) up to 36 V. Exceeding 37 V risks permanent damage; operation near the upper limit requires thermal derating based on package RθJA = 371.7 °C/W and ambient temperature.
Does TL431LIAQDBZRQ1 require an external output capacitor for stability?
No, TL431LIAQDBZRQ1 is internally compensated and remains stable without an external capacitor between CATHODE and ANODE. However, if added for noise filtering or transient suppression, capacitor value must be selected per Figure 12 stability boundary curves - typically 0.001 µF to 10 µF depending on load conditions and layout parasitics.
How does the reference input current (IREF) affect resistor-divider accuracy in TL431LIAQDBZRQ1 designs?
IREF (≤0.4 µA) flows into the REF pin and creates voltage error across the upper resistor (R1) of the feedback divider. For example, with R1 = 100 kΩ, this introduces up to 40 mV offset - ~1.6% error relative to 2.495 V. To limit error to <0.1%, R1 should be ≤10 kΩ, ensuring IREF×R1 ≤ 2.5 mV.
Can TL431LIAQDBZRQ1 be used as a comparator, and what is its typical response time?
Yes, TL431LIAQDBZRQ1 functions as a comparator with integrated 2.495 V reference when operated open-loop. Response time depends on cathode current: with IKA = 5 mA, propagation delay is <1 µs; at IKA = 0.6 mA (minimum regulation current), delay increases significantly due to reduced gain - design must ensure ≥1 mA for reliable comparator operation.
What is the difference between TL431LIAQDBZRQ1 and TL432LIAQDBZRQ1?
TL431LIAQDBZRQ1 and TL432LIAQDBZRQ1 share identical electrical specifications, AEC-Q100 Grade 1 qualification, and 1% VREF tolerance, but differ in DBZ-package pinout: TL431LIAQDBZRQ1 has CATHODE on Pin 1 and REF on Pin 2, whereas TL432LIAQDBZRQ1 swaps these (REF on Pin 1, CATHODE on Pin 2). They are not pin-compatible.
TL431LIAQDBZRQ1 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 ~ 125°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
TL431LIAQDBZRQ1 FAQ
1.How can I place an order for TL431LIAQDBZRQ1 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431LIAQDBZRQ1 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 TL431LIAQDBZRQ1 reliable?
The price and inventory of TL431LIAQDBZRQ1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431LIAQDBZRQ1 is usually 5 days.
3.What payment methods are accepted for TL431LIAQDBZRQ1?
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4.How is shipping managed for TL431LIAQDBZRQ1?
TL431LIAQDBZRQ1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431LIAQDBZRQ1 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 TL431LIAQDBZRQ1?
For technical support, including TL431LIAQDBZRQ1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431LIAQDBZRQ1 requirements.
6.How does Aetrix verify that TL431LIAQDBZRQ1 is sourced from the original manufacturer or authorized distributors?
All TL431LIAQDBZRQ1 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 TL431LIAQDBZRQ1 meets industry standards.
7.What is the process for return or replacement of TL431LIAQDBZRQ1?
All TL431LIAQDBZRQ1 units undergo pre-shipment inspection (PSI). If there is an issue with TL431LIAQDBZRQ1, 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 TL431LIAQDBZRQ1 part is unused and in its original packaging.
Return procedure for TL431LIAQDBZRQ1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431LIAQDBZRQ1 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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