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Texas Instruments TL431AQDBZRQ1
- Part No.:
- TL431AQDBZRQ1
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TL431AQDBZRQ1.pdf
- Description:
- IC VREF SHUNT ADJ 1% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:8,644
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Product details
Overview
TL431AQDBZRQ1 from Texas Instruments is an AEC-Q100 Grade 1 qualified adjustable precision shunt regulator with 0.5% reference voltage tolerance at 25°C, 14 mV max reference voltage deviation over –40°C to 125°C, 0.2 Ω typical dynamic impedance, and 1 mA to 100 mA sink-current capability. It functions as a programmable Zener replacement in automotive secondary-side flyback regulation.
For engineers reviewing the TL431AQDBZRQ1 datasheet, TL431AQDBZRQ1 pinout, TL431AQDBZRQ1 application, or TL431AQDBZRQ1 equivalent, key selection factors include its automotive-grade thermal stability, low-output-impedance error amplification, cathode-voltage-adjustable output (2.5 V to 36 V), and SOT-23-3 package compatibility with space-constrained power supervision circuits.
Technical Context
The TL431AQDBZRQ1 integrates a precision 2.495 V bandgap reference and high-gain transconductance amplifier in a single silicon die, enabling closed-loop voltage regulation via external resistor feedback between CATHODE and REF pins. Its Darlington output stage delivers up to 100 mA sink current while maintaining <0.5% initial accuracy and <34 mV total reference drift across automotive temperature range.
In open-loop mode, it operates as a comparator with integrated reference-requiring ≥1 mA cathode current for stable gain and ≤4 µA reference input current to avoid loading errors. Stability is internally compensated, eliminating mandatory output capacitance but supporting optional CL-based phase margin tuning per TI's boundary charts.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VREF @ 25°C | 2483–2507 mV (0.5% B-grade tolerance; enables ±12.5 mV absolute reference setting at room temperature) |
| VI(DEV) | 14–34 mV (max deviation over –40°C to 125°C; defines worst-case output voltage shift in automotive thermal cycling) |
| |ZKA| | 0.2–0.5 Ω (dynamic impedance at 1–100 mA; ensures <50 mV load regulation error for 10 mA step changes) |
| IKA Range | 0.7–100 mA (minimum cathode current for regulation is 0.7 mA; supports low-power biasing in standby modes) |
| ΔVREF/ΔVKA | –1.0 to –2.7 mV/V (cathode voltage feedthrough coefficient; limits output voltage drift to <70 mV over 36 V cathode swing) |
| IREF | 2–4 µA (reference pin input current; sets maximum allowable series resistance before >10 mV offset error) |
| IOFF | 0.1–0.5 µA (off-state cathode leakage at 36 V; guarantees <1 µW quiescent loss in undervoltage lockout circuits) |
Pinout & Package
SOT-23-3 (DBZ) package: 2.92 mm × 1.30 mm body, gull-wing leads, 0.95 mm pitch, JEDEC MO-178AC compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - CATHODE | Current sink output / voltage sense node | Primary shunt path; connects to regulated rail or SMPS transformer secondary; must sustain ≥1 mA for regulation |
| 2 - REF | High-impedance reference threshold input | Compares external voltage divider ratio against internal 2.495 V reference; requires ≤4 µA drive current |
| 3 - ANODE | Common return / ground reference | Die substrate connection; must be tied to system ground or lowest potential node; not floating |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q100 Grade 1 qualification | Validated for –40°C to 125°C ambient operation in automotive ECUs, ADAS sensors, and body control modules |
| 0.5% VREF tolerance (B-grade) | Reduces calibration overhead in battery monitoring and DC-DC feedback loops; eliminates need for post-solder trimming |
| 0.2 Ω dynamic impedance | Enables <1% load regulation error in 12 V automotive rails with 100 mA output swings without external compensation |
| Internal compensation | Operates stably without cathode-to-anode capacitor-simplifies layout in compact infotainment power supplies |
| Comparator mode support | Provides integrated 2.495 V threshold for undervoltage/overvoltage detection with <10 µs response when IKA ≥ 5 mA |
Applications
| Automotive Battery Monitoring | Flyback SMPS Secondary Regulation |
|---|---|
Use Scenario: Real-time 12 V battery voltage tracking in engine control units under cranking conditions (6–16 V). IC Role / Device Role / Timing Role: Adjustable shunt reference comparing divided battery voltage against internal 2.495 V; triggers fault flag when VBAT drops below 10.5 V. Use Value: 0.5% VREF tolerance ensures ±50 mV trip-point accuracy across temperature; 14 mV VI(DEV) guarantees <0.5% total error over full automotive range. |
Use Scenario: Isolated output voltage regulation in 5 V/3 A automotive USB charger using optocoupler feedback. IC Role / Device Role / Timing Role: Error amplifier sinking optocoupler LED current proportional to output deviation; replaces discrete op amp + Zener. Use Value: 0.2 Ω |ZKA| minimizes feedback loop gain variation; internal compensation avoids instability with PCB trace inductance in compact layouts. |
| Zener Diode Replacement | Overvoltage Protection Circuit |
Use Scenario: Replacing 3.3 V Zener in CAN transceiver bias network where temperature drift degrades ESD immunity margin. IC Role / Device Role / Timing Role: Precision 3.3 V clamp using R1/R2 divider on REF; sinks excess current above threshold to protect PHY inputs. Use Value: 14 mV VI(DEV) provides 4× tighter voltage stability than standard 5% Zener over –40°C to 125°C, preserving noise margin. |
Use Scenario: Detecting >15.5 V battery overvoltage in 12 V starter-generator systems to disable alternator field winding. IC Role / Device Role / Timing Role: Comparator with REF pin tied to 15.5 V divider; pulls cathode low to activate MOSFET gate driver upon overvoltage event. Use Value: 2–4 µA IREF enables use of high-value resistors (e.g., 1 MΩ) to minimize standby current; 100 mA sink capability drives logic-level FET directly. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431AIDBZRQ1 | A-grade (1% VREF tolerance); identical pinout, package, and thermal specs | Higher production yield in cost-sensitive non-safety-critical modules (e.g., HVAC controls) | Select when ±25 mV reference accuracy suffices and B-grade cost premium is unjustified |
| TL431LIQDBZRQ1 | Lower VI(DEV) (≤10 mV), lower IREF (≤2 µA), improved stability margin with CL | Required for ASIL-B functional safety paths needing tighter drift budget and lower bias current | Choose for next-gen ADAS domain controllers where reference drift contributes to ISO 26262 FMEDA failure rate |
Compared with TL431AQDBZRQ1, TL431AIDBZRQ1 trades 0.5% accuracy for lower unit cost in non-critical subsystems, while TL431LIQDBZRQ1 improves long-term stability and reduces input loading-making it suitable for safety-critical voltage supervision where TL431AQDBZRQ1 meets baseline AEC-Q100 but not ASIL requirements.
Availability
TL431AQDBZRQ1 is available at Aetrix Electronics and suitable for automotive battery management, flyback SMPS regulation, and overvoltage protection circuits requiring stable component supply with AEC-Q100 compliance and extended temperature operation.
Supply support for TL431AQDBZRQ1 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 TL43x-Q1 product line delivers AEC-Q100-qualified precision references and shunt regulators designed specifically for automotive power conversion, battery sensing, and fault-detection systems demanding robustness across extreme temperature and vibration environments.
FAQ
What is the reference voltage tolerance of TL431AQDBZRQ1 at 25°C?
The TL431AQDBZRQ1 has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a VREF range of 2483 mV to 2507 mV. This B-grade specification is confirmed in Section 6.7 of the official TI datasheet SGLS302G and enables high-accuracy voltage setting without post-manufacturing calibration. The TL431AQDBZRQ1 achieves this tighter tolerance through laser-trimmed internal resistors during wafer test.
Does TL431AQDBZRQ1 require an external output capacitor for stability?
No, TL431AQDBZRQ1 is internally compensated and operates stably without an external cathode-to-anode capacitor under typical operating conditions. However, TI's stability boundary charts (Figures 12–13 in SGLS302G) show that adding a 1–10 nF capacitor can extend phase margin when driving capacitive loads >100 pF or operating at high cathode voltages (>24 V). The TL431AQDBZRQ1's internal compensation eliminates mandatory external components but allows optional optimization.
What is the minimum cathode current required for regulation in TL431AQDBZRQ1?
The TL431AQDBZRQ1 requires a minimum cathode current (IMIN) of 0.7 mA to maintain regulation, as specified in Section 6.3 of the TI datasheet. This value applies across the full –40°C to 125°C temperature range and ensures sufficient bias for the internal Darlington output stage. Operating below 0.7 mA may cause gain collapse, increased output impedance, and delayed response-critical to verify in low-power sleep-mode designs using TL431AQDBZRQ1.
How does TL431AQDBZRQ1 differ from TL431AIDBZRQ1?
TL431AQDBZRQ1 and TL431AIDBZRQ1 share identical SOT-23-3 packaging, pinout, and automotive qualification, but differ in reference voltage tolerance: TL431AQDBZRQ1 is B-grade (±0.5%), while TL431AIDBZRQ1 is A-grade (±1%). Both exhibit identical 14–34 mV VI(DEV) and 0.2–0.5 Ω |ZKA|. The TL431AQDBZRQ1's tighter tolerance supports higher-accuracy applications like battery cell monitoring, whereas TL431AIDBZRQ1 suits cost-sensitive non-safety functions.
Can TL431AQDBZRQ1 be used as a comparator?
Yes, TL431AQDBZRQ1 functions as a comparator with integrated 2.495 V reference when operated open-loop. It requires ≥1 mA cathode current for adequate gain and responds within <10 µs when overdriven by ≥10% of VREF. In this mode, the REF pin serves as the threshold input, and the CATHODE pin outputs a low-voltage sink signal. TI application note SNVA212 confirms TL431AQDBZRQ1's suitability for undervoltage lockout and overvoltage detection in automotive systems.
TL431AQDBZRQ1 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:
- 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:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
TL431AQDBZRQ1 FAQ
1.How can I place an order for TL431AQDBZRQ1 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431AQDBZRQ1 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 TL431AQDBZRQ1 reliable?
The price and inventory of TL431AQDBZRQ1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431AQDBZRQ1 is usually 5 days.
3.What payment methods are accepted for TL431AQDBZRQ1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431AQDBZRQ1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431AQDBZRQ1?
TL431AQDBZRQ1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431AQDBZRQ1 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 TL431AQDBZRQ1?
For technical support, including TL431AQDBZRQ1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431AQDBZRQ1 requirements.
6.How does Aetrix verify that TL431AQDBZRQ1 is sourced from the original manufacturer or authorized distributors?
All TL431AQDBZRQ1 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 TL431AQDBZRQ1 meets industry standards.
7.What is the process for return or replacement of TL431AQDBZRQ1?
All TL431AQDBZRQ1 units undergo pre-shipment inspection (PSI). If there is an issue with TL431AQDBZRQ1, 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 TL431AQDBZRQ1 part is unused and in its original packaging.
Return procedure for TL431AQDBZRQ1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431AQDBZRQ1 Tags
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TL431AIDBZR
Texas Instruments
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TL431BQDBZR
Texas Instruments
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LM4040CYM3-2.5-TR
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LM4040EIM3-2.5/NOPB
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AZ431LBNTR-G1
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LM4040D20IDBZR
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LM4041DIM3-ADJ/NOPB
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LM4040DIM3X-2.5/NOPB
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LM4040DIM3-2.5/NOPB
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AZ431LANTR-G1
Diodes Incorporated
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