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Texas Instruments TL1431QDRG4
- Part No.:
- TL1431QDRG4
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
TL1431QDRG4.pdf
- Description:
- IC VREF SHUNT ADJ 0.4% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,520
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Product details
Overview
TL1431QDRG4 from Texas Instruments is an automotive-grade precision programmable shunt voltage reference IC with 0.4% initial voltage tolerance (2.490–2.510 V at 25°C), 0.2 Ω typical output impedance, and fast 500 ns turn-on time. It operates as a 2.5 V to 36 V adjustable reference in secondary-side regulation of flyback SMPSs, replacing Zener diodes in onboard voltage monitoring and error amplification circuits.
For engineers reviewing the TL1431QDRG4 datasheet, TL1431QDRG4 pinout, TL1431QDRG4 application, or TL1431QDRG4 equivalent, this page delivers verified electrical specs, SOIC-8 package mapping, automotive temperature range (–40°C to 125°C), cathode/anode/REF terminal roles, and two validated alternative parts for voltage reference design.
Technical Context
The TL1431QDRG4 integrates a precision 2.5 V bandgap reference and high-gain transconductance amplifier driving an internal Darlington sink stage. Its closed-loop operation uses external resistive feedback between CATHODE and REF to set output voltage from VI(ref) to 36 V, while open-loop use enables comparator functionality with integrated reference.
Thermal stability is guaranteed across –40°C to 125°C via automotive qualification; output impedance remains ≤0.4 Ω (1 kHz, 1–100 mA), and cathode current capability spans 1 mA to 100 mA with <2 µA reference input current deviation over full temperature range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.500 V ±10 mV at 25°C; enables accurate 2.5–36 V programmable output with external resistor divider |
| Initial Tolerance | ±0.4% at 25°C; ensures ≤±10 mV absolute error before temperature drift or aging |
| Output Impedance | 0.2 Ω typical (≤0.4 Ω max); maintains tight regulation under load current changes up to 100 mA |
| Turn-on Time | 500 ns; supports fast transient response in clamp and protection circuits |
| Operating Temp | –40°C to +125°C; qualified for automotive powertrain and body electronics applications |
| Cathode Current | 1 mA to 100 mA sink capability; allows direct interface with optocouplers and error amplifiers |
| Ref Input Current | 1.5–2.5 µA typical at 25°C; minimizes resistor-divider loading error in precision feedback networks |
Pinout & Package
TL1431QDRG4 is housed in an 8-pin SOIC (D) package measuring 3.90 mm × 4.90 mm, with exposed pad not present and RoHS-compliant lead finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Shunt current output / voltage sense node | Sinks regulated current; connects to SMPS output or feedback loop; voltage referenced to ANODE |
| ANODE (Pins 2,3,6,7) | Common ground reference / return path | Internally tied together; must be connected to system ground or low-side return for proper biasing |
| REF (Pin 8) | Reference input / feedback node | Compares external voltage to internal 2.5 V reference; requires ≥5 µA bias current for linear operation |
| NC (Pins 4,5) | No internal connection | Not bonded; must remain unconnected per TI specification to avoid parasitic coupling |
Key Features
| Feature | Design Value |
|---|---|
| Automotive Temperature Range | Qualified from –40°C to +125°C per AEC-Q100 guidelines, enabling use in engine control and ADAS power supplies |
| Low Output Impedance | 0.2 Ω typical ensures <25 mV output shift under 100 mA load step-critical for stable secondary-side regulation |
| Integrated Reference + Amplifier | Eliminates need for external op-amp and precision reference in error amplifier designs, reducing BOM count by ≥2 components |
| Zener Replacement Capability | Programmable 2.5–36 V output with sharp turn-on replaces discrete Zener diodes while improving accuracy and thermal drift |
| Internal Compensation | Stable without external capacitor between CATHODE and ANODE, simplifying layout and reducing cost in space-constrained designs |
Applications
| Secondary-Side Regulation | Zener Diode Replacement |
|---|---|
Use Scenario: Isolated flyback converter in automotive infotainment power supply requiring precise 5 V output regulation. IC Role / Device Role / Timing Role: Shunt regulator providing feedback signal to optocoupler, closing voltage loop on secondary side. Use Value: Enables ±1% output accuracy over –40°C to 125°C without primary-side sensing, reducing transformer complexity and cost. | Use Scenario: Overvoltage clamp circuit protecting MCU I/O pins from 12 V battery transients in body control module. IC Role / Device Role / Timing Role: Precision voltage clamp activated at 13.8 V threshold using external resistor network. Use Value: Replaces 13.8 V Zener with ±0.4% tolerance and 0.2 Ω dynamic impedance, cutting clamping voltage variation by >5× vs discrete Zener. |
| Voltage Monitoring | Comparator with Integrated Reference |
Use Scenario: Real-time monitoring of 24 V rail in commercial vehicle telematics unit for brownout detection. IC Role / Device Role / Timing Role: High-impedance reference input senses rail voltage; CATHODE sinks current when threshold exceeded. Use Value: Delivers 2.5 V reference stability <±20 mV over full temperature range, eliminating need for external reference IC. | Use Scenario: Window comparator detecting battery voltage between 11.5 V and 14.5 V in start-stop system. IC Role / Device Role / Timing Role: Dual TL1431QDRG4 units configured as high/low threshold comparators with shared reference. Use Value: Integrates reference and comparator function in single SOIC-8 package, reducing footprint by 40% vs op-amp + reference solution. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar programmable shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431CDBVR | Commercial temp range (0°C to 70°C); 1% initial tolerance; same SOIC-5 pinout but only 5 pins | Limited to non-automotive applications; lacks ANODE redundancy and automotive qualification | Select for cost-sensitive industrial power supplies where extended temperature range is unnecessary |
| TL1431QDG4 | Same automotive qualification and specs, but in SOIC-8 with green (RoHS) finish instead of lead-free matte tin | Identical functional performance; differs only in surface finish and JEDEC moisture sensitivity level | Choose when legacy assembly processes require SnPb-compatible finish or specific MSL rating |
Compared with TL1431QDRG4, TL431CDBVR trades automotive reliability and tighter tolerance for lower cost and smaller footprint, while TL1431QDG4 offers identical electrical behavior with alternate plating-making TL1431QDRG4 optimal for new automotive designs demanding highest precision and AEC-Q100 compliance.
Availability
TL1431QDRG4 is available at Aetrix Electronics and suitable for automotive power management, industrial SMPS feedback loops, and precision voltage monitoring requiring stable component supply across extended temperature ranges.
Supply support for TL1431QDRG4 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 industrial, automotive, and communications markets.
The TL1431 product line delivers precision programmable shunt references optimized for secondary-side regulation, Zener replacement, and integrated comparator applications in harsh-environment power systems.
FAQ
What is the maximum cathode voltage rating for TL1431QDRG4?
The absolute maximum cathode voltage (VKA) for TL1431QDRG4 is 37 V, with recommended operating range up to 36 V referenced to ANODE. Exceeding 37 V risks permanent damage per TI's Absolute Maximum Ratings table. This limit enables safe use in 24 V and 36 V automotive and industrial bus systems when properly biased.
Does TL1431QDRG4 require an external capacitor for stability?
No, TL1431QDRG4 is internally compensated and stable without any external capacitor between CATHODE and ANODE. However, if a capacitive load is introduced by downstream circuitry (e.g., optocoupler input capacitance), designers must verify operation against the stability boundary chart in Figure 5-12 of the datasheet to prevent oscillation.
How does the REF pin function in TL1431QDRG4 closed-loop operation?
In closed-loop operation, the REF pin serves as the high-impedance input that compares external feedback voltage (from resistor divider) to the internal 2.5 V reference. When feedback voltage equals 2.5 V, the device regulates CATHODE voltage to maintain equilibrium. REF requires ≥5 µA bias current to activate the internal NPN transistor and ensure linear amplifier operation.
Can TL1431QDRG4 replace a standard 3.3 V Zener diode directly?
Yes, TL1431QDRG4 can replace a 3.3 V Zener by configuring R1 and R2 to set cathode voltage to 3.3 V (e.g., R1 = 3.3 kΩ, R2 = 10 kΩ). Unlike Zeners, it provides ±0.4% initial accuracy, <20 mV tempco drift, and 0.2 Ω dynamic impedance-yielding significantly tighter regulation and lower leakage under varying loads and temperatures.
What is the minimum cathode current required for regulation in TL1431QDRG4?
The minimum cathode current (Imin) for regulation in TL1431QDRG4 is 0.45 mA at 25°C, with 1 mA specified as maximum under recommended conditions. Supplying <0.45 mA may cause loss of regulation or increased output impedance; typical designs use ≥1 mA to ensure robust operation across –40°C to 125°C.
TL1431QDRG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- 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
TL1431QDRG4 FAQ
1.How can I place an order for TL1431QDRG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL1431QDRG4 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 TL1431QDRG4 reliable?
The price and inventory of TL1431QDRG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL1431QDRG4 is usually 5 days.
3.What payment methods are accepted for TL1431QDRG4?
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Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL1431QDRG4?
TL1431QDRG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL1431QDRG4 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 TL1431QDRG4?
For technical support, including TL1431QDRG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL1431QDRG4 requirements.
6.How does Aetrix verify that TL1431QDRG4 is sourced from the original manufacturer or authorized distributors?
All TL1431QDRG4 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 TL1431QDRG4 meets industry standards.
7.What is the process for return or replacement of TL1431QDRG4?
All TL1431QDRG4 units undergo pre-shipment inspection (PSI). If there is an issue with TL1431QDRG4, 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 TL1431QDRG4 part is unused and in its original packaging.
Return procedure for TL1431QDRG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL1431QDRG4 Tags
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