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Texas Instruments TL1431QDG4
- Part No.:
- TL1431QDG4
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
TL1431QDG4.pdf
- Description:
- IC VREF SHUNT ADJ 0.4% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,863
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Product details
Overview
TL1431QDG4 from Texas Instruments is an automotive-grade precision programmable shunt voltage reference IC with 0.4% initial voltage tolerance (2.49 V to 2.51 V at 25°C), 0.2 Ω typical output impedance, and fast 500 ns turn-on time. It operates as a 2.5 V reference with adjustable cathode output up to 36 V using two external resistors, and sinks 1 mA to 100 mA - widely used in secondary-side regulation of flyback SMPSs for EV charging modules and ADAS power supplies.
For engineers reviewing the TL1431QDG4 datasheet, TL1431QDG4 pinout, TL1431QDG4 application, or TL1431QDG4 equivalent, key selection criteria include its –40°C to 125°C automotive temperature rating, low 2.5 µA typical reference input current, sharp turn-on characteristic for comparator use, and internal Darlington sink stage enabling stable Zener replacement without external compensation capacitors.
Technical Context
The TL1431QDG4 integrates a precision 2.5 V bandgap reference and high-gain transconductance amplifier driving an NPN Darlington output stage. Its functional block includes a reference node (REF), common return (ANODE), and current-sinking output (CATHODE), enabling closed-loop error amplification or open-loop comparator operation.
It achieves thermal stability via on-chip curvature compensation, with reference voltage deviation ≤55 mV over –40°C to 125°C and temperature coefficient ≤20 ppm/°C. The device maintains regulation with ≥0.45 mA minimum cathode current and exhibits <0.5 µA off-state leakage at 36 V cathode voltage.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.500 V ±10 mV at 25°C; enables precise 2.5 V基准 generation or programmable output from 2.5 V to 36 V |
| Initial Tolerance | ±0.4% at 25°C; ensures ≤±10 mV absolute error before calibration or trimming |
| Output Impedance | 0.2 Ω typical at 1 kHz; provides tight regulation under dynamic load changes up to 100 mA |
| Cathode Current Range | 1 mA to 100 mA sink capability; supports robust shunt regulation in high-current feedback loops |
| Operating Temperature | –40°C to +125°C; qualified for automotive under-hood and infotainment power supply applications |
| Turn-on Time | 500 ns; enables fast response in overvoltage protection and transient clamp circuits |
| Reference Input Current | 2.5 µA typical at 25°C; minimizes resistor-divider loading error in high-impedance programming networks |
Pinout & Package
TL1431QDG4 is housed in an SOIC-8 (D) package measuring 3.90 mm × 4.90 mm, with ANODE pins internally bonded together for low-inductance ground return.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Current-sink output terminal | Primary regulated node; connects to feedback point in SMPS secondary side or voltage clamp load |
| ANODE (Pins 2, 3, 6, 7) | Common reference and ground return | Internally shorted pins; must be connected to system ground or power return to complete shunt path |
| REF (Pin 8) | Reference input sensing node | High-impedance threshold input; tied to resistor divider midpoint to set regulated cathode voltage |
| NC (Pins 4, 5) | No internal connection | Unused; must remain unconnected or grounded per layout best practices to avoid parasitic coupling |
Key Features
| Feature | Design Value |
|---|---|
| Automotive qualification | Specified and tested across –40°C to +125°C; meets AEC-Q100 stress requirements for automotive electronics |
| Internal Darlington output | Enables 100 mA sink current with low saturation voltage; eliminates need for external pass transistor in shunt regulators |
| Zero-output-capacitor stability | Internally compensated for unity-gain stability; operates reliably without cathode-to-anode capacitor in most configurations |
| Low reference current | 2.5 µA typical at 25°C; reduces divider resistor power loss and thermal drift in high-precision voltage setting |
| Zener diode replacement | Programmable 2.5 V to 36 V output with superior thermal stability and tighter tolerance than discrete Zeners |
Applications
| EV Onboard Charger Feedback | Flyback SMPS Secondary Regulation |
|---|---|
Use Scenario: Regulating isolated 12 V auxiliary rail in 3.3 kW OBC using optocoupler-coupled feedback loop. IC Role / Device Role / Timing Role: Precision shunt reference providing stable 2.5 V threshold for error amplifier comparison against scaled output voltage. Use Value: Enables ±1% output voltage accuracy over full temperature and line/load range, meeting ISO 16750-2 automotive supply requirements. |
Use Scenario: Voltage sensing and regulation in 65 W flyback converter powering ADAS camera ECU. IC Role / Device Role / Timing Role: Adjustable reference generating 5.0 V cathode output via R1/R2 divider; drives optocoupler LED to close feedback loop. Use Value: Delivers 500 ns response to load transients, maintaining <100 mV output deviation during 1 A step load change. |
| Programmable Overvoltage Clamp | Comparator with Integrated Reference |
Use Scenario: Protecting 24 V CAN FD bus transceiver from >28 V surges in commercial vehicle telematics module. IC Role / Device Role / Timing Role: Shunt regulator configured as clamping circuit with REF tied to 24 V rail and CATHODE sinking excess current above threshold. Use Value: Clamps within 500 ns at 28.0 V ±0.1 V, limiting transient energy dissipation to <1.2 J per event. |
Use Scenario: Monitoring battery cell voltage in 12S Li-ion BMS for overvoltage detection at 4.25 V/cell. IC Role / Device Role / Timing Role: Open-loop comparator with REF biased to 4.25 V reference divider; CATHODE drives MOSFET gate to disconnect cell. Use Value: Achieves <10 mV trip threshold accuracy and <1 µs propagation delay, enabling fast fault isolation per ISO 6469-3. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431QDBVR | Same SOIC-8 package; 1% initial tolerance (vs. 0.4%); wider –40°C to 125°C spec but higher 5 µA max II(ref) | Suitable for cost-sensitive automotive systems where ±1% output accuracy is acceptable | Select when budget constraints outweigh need for tight reference tolerance and lower bias current |
| LM4040CIM3-ADJ/NOPB | Series shunt reference (not adjustable sink); fixed 2.5 V output; 0.5% tolerance; 70 µA max quiescent current | Limited to 2.5 V only; no adjustable output or sink capability; requires external series resistor for current limiting | Choose only for simple 2.5 V reference needs where sink current and programmability are unnecessary |
Compared with TL431QDBVR and LM4040CIM3-ADJ/NOPB, TL1431QDG4 uniquely combines automotive temperature range, 0.4% tolerance, programmable 2.5–36 V output, and 100 mA sink capability in one SOIC-8 device - making it irreplaceable for precision flyback regulation and fast-response clamping where both accuracy and drive strength are required.
Availability
TL1431QDG4 is available at Aetrix Electronics and suitable for automotive power conversion, industrial SMPS design, and battery management systems requiring stable component supply with guaranteed long-term availability and traceable sourcing.
Supply support for TL1431QDG4 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 leader specializing in analog, embedded processing, and power management ICs, with decades of automotive-qualified product development.
The TL1431 product line delivers precision programmable shunt references optimized for automotive, industrial, and telecom power supply feedback loops - designed to replace Zener diodes while improving accuracy, stability, and integration.
FAQ
What is the maximum cathode voltage rating for TL1431QDG4?
The absolute maximum cathode voltage (VKA) for TL1431QDG4 is 37 V, with recommended operating range up to 36 V referenced to ANODE. Exceeding 37 V risks permanent damage. This rating enables safe use in 24 V and 48 V automotive systems with margin for transients, and is validated across the full –40°C to 125°C temperature range per TI's SLVS062O datasheet Section 5.1.
Does TL1431QDG4 require an external compensation capacitor?
No, TL1431QDG4 is internally compensated and stable without any external capacitor between CATHODE and ANODE. Its design eliminates the need for output capacitance in standard shunt regulator configurations, though optional capacitors may be added for enhanced transient response - provided they fall within the stability boundary defined in Figure 5-12 of the datasheet. This simplifies layout and improves reliability in space-constrained automotive modules.
How does TL1431QDG4 differ from commercial-grade TL1431CDG4?
TL1431QDG4 is qualified for –40°C to 125°C operation and undergoes additional automotive stress testing per AEC-Q100, whereas TL1431CDG4 is rated only from 0°C to 70°C. Both share identical electrical specs (0.4% tolerance, 0.2 Ω impedance), but TL1431QDG4 guarantees performance and reliability in under-hood environments - critical for engine control units, ADAS sensors, and EV power electronics where extended temperature operation is mandatory.
Can TL1431QDG4 be used as a comparator?
Yes, TL1431QDG4 functions as a high-gain comparator with integrated 2.5 V reference when operated open-loop: connect REF to a voltage divider sensing the signal to monitor, and use CATHODE as the digital output (sinking current when input exceeds 2.5 V). Its 500 ns turn-on time and low input bias current (2.5 µA typ.) enable fast, accurate level detection - confirmed in Section 7.4.1 and Figure 8-1 of the TL1431QDG4 datasheet.
What is the minimum cathode current needed for regulation in TL1431QDG4?
TL1431QDG4 requires a minimum cathode current (Imin) of 0.45 mA at 25°C to maintain regulation, increasing slightly at temperature extremes. Below this threshold, the internal amplifier exits linear region and reference accuracy degrades. This value is specified in Section 5.6 (Electrical Characteristics – TL1431Q) of the datasheet and must be ensured by proper RSUP sizing in all applications - especially in low-power standby modes of automotive SMPS designs.
TL1431QDG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Tube
- Product Status:
- Discontinued at Digi-Key
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 2.5V
- Voltage - Output (Max):
- 36 V
- Current - Output:
- 100 mA
- Tolerance:
- ±0.4%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 1 mA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
TL1431QDG4 FAQ
1.How can I place an order for TL1431QDG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL1431QDG4 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 TL1431QDG4 reliable?
The price and inventory of TL1431QDG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL1431QDG4 is usually 5 days.
3.What payment methods are accepted for TL1431QDG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL1431QDG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL1431QDG4?
TL1431QDG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL1431QDG4 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 TL1431QDG4?
For technical support, including TL1431QDG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL1431QDG4 requirements.
6.How does Aetrix verify that TL1431QDG4 is sourced from the original manufacturer or authorized distributors?
All TL1431QDG4 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 TL1431QDG4 meets industry standards.
7.What is the process for return or replacement of TL1431QDG4?
All TL1431QDG4 units undergo pre-shipment inspection (PSI). If there is an issue with TL1431QDG4, 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 TL1431QDG4 part is unused and in its original packaging.
Return procedure for TL1431QDG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL1431QDG4 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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