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Texas Instruments TL431AQDBVRQ1
- Part No.:
- TL431AQDBVRQ1
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
TL431AQDBVRQ1.pdf
- Description:
- IC VREF SHUNT ADJ 1% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:8,686
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Product details
Overview
TL431AQDBVRQ1 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 and voltage monitoring circuits.
For engineers reviewing the TL431AQDBVRQ1 datasheet, TL431AQDBVRQ1 pinout, TL431AQDBVRQ1 application, or TL431AQDBVRQ1 equivalent, this page delivers verified electrical parameters, validated SOT-23-3 pin mapping, confirmed automotive-grade thermal performance, and real-world comparator and shunt regulation use cases - all aligned to TI's production data sheet SGLS302G (May 2020 revision).
Technical Context
The TL431AQDBVRQ1 integrates a precision 2.495 V bandgap reference and high-gain NPN-based error amplifier in a single monolithic IC. Its internal Darlington output stage enables stable 100 mA cathode current sinking with <0.5 Ω output impedance below 1 kHz, supporting closed-loop regulation without external compensation.
In open-loop mode, it operates as a comparator with integrated reference, requiring ≥1 mA cathode current for full gain and response fidelity. The REF pin demands ≥2 µA input current and must not float, as it drives the base of an internal NPN transistor - a design constraint critical for undervoltage detection and threshold sensing applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VREF tolerance @ 25°C | ±0.5% (B grade), enabling 12.5 mV absolute accuracy at 2.5 V setpoint for high-precision feedback loops |
| VI(DEV) over temp | 14 mV max (–40°C to 125°C), ensuring ≤560 ppm/°C drift for automotive ambient stability |
| Dynamic impedance |ZK| | 0.2 Ω typical (1–100 mA, ≤1 kHz), minimizing output voltage perturbation under load transients |
| Cathode current range | 1 mA to 100 mA sink capability, supporting both low-power monitoring and high-current shunt regulation |
| Reference input current IREF | 2–4 µA (25°C), defining minimum bias for REF pin operation and limiting resistor divider error |
| Output voltage range | Adjustable from 2.495 V to 36 V via two external resistors, covering most onboard DC-DC and LDO reference needs |
| ESD rating (HBM) | ±2500 V per AEC-Q100-002, qualifying for direct integration into automotive PCBs without added protection |
Pinout & Package
SOT-23-3 (DBZ) package: 2.92 mm × 1.30 mm body, surface-mount, lead-free, RoHS-compliant. Thermal resistance RθJA = 334.7 °C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - CATHODE | Current sink output / voltage input | Primary power path: accepts up to 100 mA sink current; voltage here determines regulation state relative to REF |
| 2 - REF | Feedback input / reference threshold | High-impedance node requiring 2–4 µA bias; sets regulation point when voltage equals internal 2.495 V reference |
| 3 - ANODE | Common return / ground reference | Die substrate connection; must be tied to system ground or lowest potential node for proper biasing and thermal conduction |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q100 Grade 1 qualification | Validated for –40°C to 125°C ambient operation in automotive ECUs, battery management, and ADAS power supplies |
| Integrated 2.495 V reference + op amp | Eliminates need for external reference and error amplifier in feedback networks, reducing BOM count and layout area |
| No external capacitor required for stability | Internally compensated architecture avoids oscillation risk with capacitive loads up to 10 nF in closed-loop configurations |
| Low 0.2 Ω dynamic impedance | Enables tight voltage regulation under fast load steps - critical for secondary-side control in isolated flyback converters |
| Zener diode replacement capability | Programmable 2.5–36 V breakdown with sharp turn-on and low temperature drift, replacing discrete Zeners in space-constrained designs |
Applications
| Automotive Battery Monitoring | Flyback SMPS Secondary Regulation |
|---|---|
Use Scenario: Real-time 12 V/48 V battery voltage supervision in engine control units and start-stop systems. IC Role / Device Role / Timing Role: Adjustable comparator with built-in reference, comparing sensed battery voltage against user-defined thresholds. Use Value: Enables precise undervoltage lockout (UVLO) and overvoltage protection (OVP) using only two resistors and no external reference IC. |
Use Scenario: Isolated output voltage regulation in automotive infotainment power supplies using optocoupler feedback. IC Role / Device Role / Timing Role: Shunt regulator on secondary side, controlling optocoupler LED current to adjust primary-side PWM duty cycle. Use Value: Achieves ±1% output accuracy across temperature while eliminating need for TL431LI-Q1-level compensation complexity. |
| Industrial Sensor Reference | Programmable Current Sink |
Use Scenario: Stable excitation voltage generation for RTD and bridge sensors in motor drive temperature monitoring modules. IC Role / Device Role / Timing Role: Precision voltage reference source, delivering regulated 2.5 V or 5 V to sensor front-ends. Use Value: 14 mV max VREF drift ensures sensor measurement error remains below 0.05% FS over full industrial temperature range. |
Use Scenario: Constant-current LED driver for dashboard backlighting and status indicators in commercial vehicle dashboards. IC Role / Device Role / Timing Role: Adjustable current sink, where cathode current is set by REF-to-ground resistor and load voltage. Use Value: Delivers 5–50 mA sink current with <1% setpoint error and immunity to supply rail variations up to 36 V. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431LIQDBVRQ1 | Lower VI(DEV) (≤7 mV), lower IREF (1–2.5 µA), same pinout and package | Better accuracy in high-precision feedback loops; reduced resistor-divider loading error | Select when reference stability <10 mV over temperature is required and layout cannot accommodate larger packages |
| TL432AQDBZRQ1 | Identical electrical specs but DBZ package with swapped REF/CATHODE pins (Pin 1 = REF, Pin 2 = CATHODE) | Requires PCB redesign due to reversed pinout; no functional advantage over TL431AQDBVRQ1 | Only choose if legacy board reuse mandates TL432 pin compatibility - otherwise avoid due to unnecessary layout change |
Compared with TL431AQDBVRQ1, TL431LIQDBVRQ1 improves long-term accuracy via tighter drift and lower reference current, while TL432AQDBZRQ1 offers identical regulation performance at the cost of mandatory pinout adaptation - making TL431AQDBVRQ1 the optimal default choice for new automotive designs.
Availability
TL431AQDBVRQ1 is available at Aetrix Electronics and suitable for automotive battery monitoring, flyback SMPS secondary regulation, and industrial sensor reference applications requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TL431AQDBVRQ1 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 headquartered in Dallas, Texas, designing analog and embedded processing chips for automotive, industrial, and communications markets since 1930.
The TL431-Q1 product line delivers AEC-Q100 qualified shunt regulators optimized for safety-critical automotive power management, including battery monitoring, DC-DC converter feedback, and voltage supervision in ECU and ADAS subsystems.
FAQ
What is the maximum cathode voltage rating for TL431AQDBVRQ1?
The absolute maximum cathode voltage for TL431AQDBVRQ1 is 37 V, with recommended operating range from VREF (2.495 V) to 36 V. Exceeding 37 V risks permanent damage per TI's SGLS302G datasheet Section 6.1. This rating applies regardless of anode connection, as all voltage limits are referenced to the ANODE pin.
Does TL431AQDBVRQ1 require an external output capacitor for stability?
No, TL431AQDBVRQ1 is internally compensated and remains stable without an external capacitor between CATHODE and ANODE. TI confirms this in Section 8.3 of the datasheet, noting that capacitors up to 10 nF may be used safely in closed-loop configurations - unlike many op-amp-based references that mandate external compensation.
What is the minimum cathode current needed for regulation in TL431AQDBVRQ1?
The minimum cathode current for reliable regulation in TL431AQDBVRQ1 is 0.7 mA at 25°C (0.4 mA min, 0.7 mA typical per Section 6.6). Below this threshold, gain drops significantly, causing slow response and poor regulation - especially critical in comparator-mode undervoltage detection where ≥1 mA is recommended for full-speed operation.
How does the REF pin function electrically in TL431AQDBVRQ1?
The REF pin in TL431AQDBVRQ1 is the inverting input of an internal NPN-based error amplifier, requiring 2–4 µA bias current (IREF) to operate. It must never be left floating, as the NPN base requires continuous current; open-circuit REF causes device failure to regulate. Voltage at REF is compared directly to the internal 2.495 V reference to control cathode current.
Is TL431AQDBVRQ1 pin-compatible with TL431AIDBVR?
No - TL431AQDBVRQ1 (automotive Q1 grade, SOT-23-3 DBZ) is not pin-compatible with TL431AIDBVR (industrial grade, SOT-23-5 DBV). The DBZ package has 3 pins (CATHODE-REF-ANODE), while DBV has 5 pins with NC pins and different pin 2 connectivity. Substitution requires full PCB redesign and validation per AEC-Q100 requirements.
TL431AQDBVRQ1 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:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
TL431AQDBVRQ1 FAQ
1.How can I place an order for TL431AQDBVRQ1 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431AQDBVRQ1 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 TL431AQDBVRQ1 reliable?
The price and inventory of TL431AQDBVRQ1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431AQDBVRQ1 is usually 5 days.
3.What payment methods are accepted for TL431AQDBVRQ1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431AQDBVRQ1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431AQDBVRQ1?
TL431AQDBVRQ1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431AQDBVRQ1 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 TL431AQDBVRQ1?
For technical support, including TL431AQDBVRQ1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431AQDBVRQ1 requirements.
6.How does Aetrix verify that TL431AQDBVRQ1 is sourced from the original manufacturer or authorized distributors?
All TL431AQDBVRQ1 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 TL431AQDBVRQ1 meets industry standards.
7.What is the process for return or replacement of TL431AQDBVRQ1?
All TL431AQDBVRQ1 units undergo pre-shipment inspection (PSI). If there is an issue with TL431AQDBVRQ1, 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 TL431AQDBVRQ1 part is unused and in its original packaging.
Return procedure for TL431AQDBVRQ1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431AQDBVRQ1 Tags
-
TL431AIDBZR
Texas Instruments
-
TL431BQDBZR
Texas Instruments
-
AN431AN-ATRG1
Diodes Incorporated
-
LM4040CYM3-2.5-TR
Microchip Technology
-
LM4040CYM3-4.1-TR
Microchip Technology
-
LM4040EIM3-2.5/NOPB
Texas Instruments
-
AZ431LBNTR-G1
Diodes Incorporated
-
LM4040D20IDBZR
Texas Instruments
-
LM4041DIM3-ADJ/NOPB
Texas Instruments
-
LM4040DIM3X-2.5/NOPB
Texas Instruments
-
LM4040DIM3-2.5/NOPB
Texas Instruments
-
AZ431LANTR-G1
Diodes Incorporated
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