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Texas Instruments ATL431LIBQDBZR
- Part No.:
- ATL431LIBQDBZR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
ATL431LIBQDBZR.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:6,403
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Product details
Overview
ATL431LIBQDBZR from Texas Instruments is a high-bandwidth, low-quiescent-current programmable shunt voltage regulator with 0.5% initial reference voltage tolerance at 25°C, 2.5 V minimum output voltage, adjustable output up to 36 V, and operation across −40°C to +125°C for automotive-grade applications. It functions as a precision 2.5 V reference with active sink capability in secondary-side regulation of flyback SMPS.
For engineers reviewing the ATL431LIBQDBZR datasheet, ATL431LIBQDBZR pinout, ATL431LIBQDBZR application, or ATL431LIBQDBZR equivalent, key selection criteria include cathode current range (0.08–15 mA), dynamic impedance (0.3 Ω typ), reference input current (≤0.4 µA), temperature drift (≤27 mV over Q-temp range), and SOT-23-3 package compatibility with TL431LI/TL432LI designs.
Technical Context
The ATL431LIBQDBZR implements a three-terminal shunt regulator architecture with an internal 2.5 V bandgap reference and high-gain NPN-based error amplifier driving a Darlington output stage. Its open-loop gain enables comparator-mode operation, while closed-loop feedback via external resistors sets precise output voltages from 2.5 V to 36 V.
It operates with a minimum cathode current of 80 µA to maintain regulation, exhibits 0.3 Ω typical dynamic impedance at 1 mA cathode current, and delivers stable performance without external compensation capacitors-though stability boundary charts guide CL selection when used with capacitive loads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage (25°C) | 2.500 V ±0.5% - Enables precision voltage setting with ≤12.5 mV absolute error at room temperature. |
| Cathode Voltage Range | 2.5 V to 36 V - Supports wide-range adjustable shunt regulation in isolated DC/DC converters. |
| Min Cathode Current | 80 µA max - Allows ultra-low-power operation; reduces system standby consumption vs TL431LI. |
| Dynamic Impedance | 0.3 Ω typ - Ensures tight output voltage regulation under varying load conditions. |
| Temp Drift (−40°C to +125°C) | 27 mV max - Guarantees ≤±13.5 mV deviation across full automotive temperature range. |
| Ref Input Current | 0.4 µA max - Minimizes resistor-divider loading error in precision feedback networks. |
| Output Temp Coefficient | ≤100 ppm/°C avg - Matches industrial and automotive timing/reference stability requirements. |
Pinout & Package
ATL431LIBQDBZR is housed in a 3-pin SOT-23 (DBZ) package measuring 2.90 mm × 1.30 mm, optimized for space-constrained automotive and industrial PCBs. The package includes gull-wing leads and is RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Shunt current input/output node | Accepts regulated sink current up to 15 mA; voltage at this pin is set by external resistor divider. |
| REF (Pin 2) | Reference input sensing node | Senses voltage relative to ANODE; must receive ≥0.4 µA bias current to enable regulation. |
| ANODE (Pin 3) | Common return path | Typically connected to system ground or low-side return; serves as voltage reference point for REF and VKA. |
Key Features
| Feature | Design Value |
|---|---|
| 0.5% reference accuracy (B grade) | Reduces calibration overhead in precision power supplies and battery monitors. |
| 0.3 Ω dynamic impedance | Maintains <10 mV output variation across 1–15 mA cathode current swing. |
| −40°C to +125°C operation (Q grade) | Qualified for under-hood automotive, industrial motor drives, and telecom power systems. |
| 80 µA min cathode current | Enables >30% lower startup current than TL431LI, improving light-load efficiency. |
| No external capacitor required | Internally compensated for stability with resistive feedback-reduces BOM count and layout area. |
Applications
| Secondary-Side Regulation | Zener Diode Replacement |
|---|---|
Use Scenario: Isolated flyback converter with optocoupler feedback loop for AC/DC adapters or EV onboard chargers. IC Role / Device Role / Timing Role: Shunt regulator providing precise voltage reference to optocoupler LED, enabling accurate primary-side duty cycle control. Use Value: 0.5% reference tolerance and 27 mV temp drift ensure ±1.5% output voltage regulation across automotive temperature range. | Use Scenario: Overvoltage protection clamp in 12 V automotive ECU power rail. IC Role / Device Role / Timing Role: Adjustable shunt element replacing discrete Zener diodes to improve accuracy and thermal stability. Use Value: 0.3 Ω dynamic impedance and sharp turn-on characteristic reduce clamping voltage overshoot by >40% vs 5% tolerance Zeners. |
| Voltage Monitoring | Precision Constant Current Sink |
Use Scenario: Undervoltage lockout (UVLO) circuit monitoring 5 V microcontroller supply in ADAS domain controller. IC Role / Device Role / Timing Role: Comparator with integrated 2.5 V reference detecting supply drop below 4.75 V threshold. Use Value: 0.4 µA max reference current minimizes sensing resistor error; 15 mA sink capability drives logic-level MOSFET gate directly. | Use Scenario: LED driver for automotive interior lighting requiring 100 mA ±2% constant current. IC Role / Device Role / Timing Role: Precision current sink using REF-to-ANODE voltage feedback and external sense resistor. Use Value: 80 µA min cathode current enables stable regulation down to 100 µA LED bias, supporting dimming modes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431LIBIDBZR | Same SOT-23-3 package; 1% initial tolerance (A grade); higher 100 µA min cathode current. | Less suitable for ultra-low-power systems; requires larger feedback resistors to meet Imin. | Select when cost sensitivity outweighs accuracy and quiescent current requirements. |
| ATL432LIBQDBZR | Identical electrical specs; different pinout (REF and ANODE swapped in DBZ package). | Not pin-compatible-requires PCB redesign; used where layout allows repositioning of feedback network. | Choose only if existing design uses ATL432LI footprint or needs alternate routing flexibility. |
Compared with TL431LIBIDBZR, ATL431LIBQDBZR delivers tighter 0.5% reference accuracy and 20% lower minimum operating current-critical for battery-backed systems. Against ATL432LIBQDBZR, it offers direct pin compatibility with legacy TL431LI layouts, avoiding board revision while maintaining Q-temp qualification.
Availability
ATL431LIBQDBZR 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 ATL431LIBQDBZR 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 delivering analog and embedded processing solutions for industrial, automotive, and communications markets.
The ATL431LI product line delivers high-accuracy, low-IQ shunt regulators designed specifically for automotive-grade secondary-side regulation, voltage supervision, and precision current sinking-addressing demands for reliability and thermal stability in harsh environments.
FAQ
What is the maximum cathode voltage rating for ATL431LIBQDBZR?
The ATL431LIBQDBZR has an absolute maximum cathode-to-anode voltage (VKA) rating of 37 V. Its recommended operating cathode voltage range is 2.5 V to 36 V. Exceeding 37 V risks permanent damage per the datasheet's Absolute Maximum Ratings table. This rating supports use in 24 V automotive systems with transient spikes, provided external clamping is applied beyond 36 V.
Does ATL431LIBQDBZR require an external capacitor for stability?
No, ATL431LIBQDBZR is internally compensated and does not require an external capacitor for basic resistive-feedback operation. However, when driving capacitive loads (e.g., optocoupler CTR compensation or long PCB traces), stability boundary charts in the datasheet (Figures 13–16) must be consulted to select appropriate load capacitance-typically ≤100 pF for robust phase margin above 1 mA cathode current.
How does the pinout of ATL431LIBQDBZR compare to TL431LI?
ATL431LIBQDBZR uses the same SOT-23-3 (DBZ) pinout as TL431LI: Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE. This enables direct drop-in replacement in existing TL431LI designs without layout changes. In contrast, ATL432LI swaps REF and ANODE pins, making it non-interchangeable in the same footprint.
What is the purpose of the ANODE pin on ATL431LIBQDBZR?
The ANODE pin on ATL431LIBQDBZR serves as the common reference node and current return path. It is typically connected to ground or the low-side rail of the power system. All internal reference and amplifier circuitry is referenced to ANODE, making it essential for proper biasing-floating or high-impedance ANODE connections will prevent regulation or cause erratic behavior.
Can ATL431LIBQDBZR be used as a comparator?
Yes, ATL431LIBQDBZR can operate as a comparator with integrated 2.5 V reference in open-loop configuration. When cathode current ≥80 µA is supplied and no feedback is applied to REF, its high open-loop gain enables fast over/under-voltage detection. Output swings between ~2 V (low) and VSUP (high), requiring level-shifting for 3.3 V or 1.8 V logic interfaces.
ATL431LIBQDBZR 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):
- 2.5V
- Voltage - Output (Max):
- 36 V
- Current - Output:
- 15 mA
- Tolerance:
- ±0.5%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 100 µA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
ATL431LIBQDBZR FAQ
1.How can I place an order for ATL431LIBQDBZR through Aetrix?
Please submit a Request for Quotation (RFQ) for ATL431LIBQDBZR 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 ATL431LIBQDBZR reliable?
The price and inventory of ATL431LIBQDBZR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ATL431LIBQDBZR is usually 5 days.
3.What payment methods are accepted for ATL431LIBQDBZR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ATL431LIBQDBZR transactions.
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4.How is shipping managed for ATL431LIBQDBZR?
ATL431LIBQDBZR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ATL431LIBQDBZR 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 ATL431LIBQDBZR?
For technical support, including ATL431LIBQDBZR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ATL431LIBQDBZR requirements.
6.How does Aetrix verify that ATL431LIBQDBZR is sourced from the original manufacturer or authorized distributors?
All ATL431LIBQDBZR 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 ATL431LIBQDBZR meets industry standards.
7.What is the process for return or replacement of ATL431LIBQDBZR?
All ATL431LIBQDBZR units undergo pre-shipment inspection (PSI). If there is an issue with ATL431LIBQDBZR, 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 ATL431LIBQDBZR part is unused and in its original packaging.
Return procedure for ATL431LIBQDBZR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
ATL431LIBQDBZR Tags
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