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Texas Instruments ATL431LIBIDBZR
- Part No.:
- ATL431LIBIDBZR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
ATL431LIBIDBZR.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:8,930
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Product details
Overview
ATL431LIBIDBZR from Texas Instruments is a precision 2.5-V adjustable shunt regulator in SOT-23-3 package, featuring 0.5% initial reference voltage tolerance at 25°C, 0.3-Ω typical dynamic impedance, and operation from −40°C to +125°C. It functions as a programmable voltage reference or error amplifier in secondary-side regulation of isolated flyback converters.
For engineers reviewing the ATL431LIBIDBZR datasheet, ATL431LIBIDBZR pinout, ATL431LIBIDBZR application, or ATL431LIBIDBZR equivalent, key selection criteria include minimum cathode current (80 µA max), reference input current (0.4 µA max), temperature drift (27 mV max over Q-temp range), and compatibility with space-constrained industrial and automotive power supplies.
Technical Context
The ATL431LIBIDBZR implements a three-terminal shunt topology with an internal 2.5-V bandgap reference and high-gain NPN-based error amplifier driving a Darlington sink output stage. Its open-loop gain enables comparator operation, while closed-loop feedback via external resistors sets output voltage from 2.5 V to 36 V.
It operates without mandatory output capacitance due to internal compensation, supports stable regulation down to 80 µA cathode current, and maintains <0.3 Ω dynamic impedance across 1–15 mA cathode current range - critical for tight voltage control in feedback loops of isolated DC/DC converters.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VREF @ 25°C | 2.500 V ±0.5% (B-grade); ensures precise setpoint for feedback networks in regulated power supplies |
| VKA Range | 2.5 V to 36 V; enables wide-range programmability using two external resistors |
| IKA Max | 15 mA; defines maximum sink capability for error amplifier or current sink applications |
| Imin Max | 80 µA; minimum cathode current required to maintain regulation - lower than TL431LI, reducing standby power |
| VI(dev) Q-temp | 27 mV over −40°C to +125°C; quantifies total reference voltage drift - critical for automotive thermal stability |
| |ZKA| Typ | 0.3 Ω at 1 mA; low dynamic impedance minimizes output voltage variation under load transients |
| IREF Max | 0.4 µA at 25°C; ultra-low reference input current reduces resistor-divider loading error |
Pinout & Package
ATL431LIBIDBZR is housed in a 2.90 mm × 1.30 mm SOT-23-3 plastic package with gull-wing leads, optimized for automated assembly and thermal performance in high-density PCB layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Current Sink Output / Voltage Sense Node | Primary current path; connects to feedback node in SMPS; voltage here is regulated relative to ANODE |
| REF (Pin 2) | Reference Input / Error Amplifier Inverting Input | Senses divided output voltage; requires ≤0.4 µA bias current; must not be left floating |
| ANODE (Pin 3) | Common Return / Ground Reference | System ground reference point; all voltages referenced to this pin; connects to power supply return |
Key Features
| Feature | Design Value |
|---|---|
| 0.5% Initial VREF Tolerance | Enables high-accuracy output regulation without post-production trimming in industrial and automotive systems |
| −40°C to +125°C Operation | Qualified for extended temperature automotive (Q-temp) applications including engine control and ADAS power rails |
| 0.3-Ω Dynamic Impedance | Minimizes output voltage deviation during fast load steps - essential for stable feedback in flyback converters |
| 80 µA Minimum Cathode Current | Reduces standby power consumption vs. legacy TL431LI (100 µA), improving efficiency in low-power modes |
| Internal Compensation | Eliminates need for external compensation capacitor in most configurations - simplifies layout and BOM |
Applications
| Secondary-Side Regulation (Flyback SMPS) | Zener Diode Replacement |
|---|---|
Use Scenario: Used in optocoupler-coupled feedback loop of isolated 12-V/5-V flyback converter powering automotive infotainment module. IC Role / Device Role / Timing Role: Adjustable shunt regulator providing precise 2.5-V reference to error amplifier; regulates output by modulating optocoupler LED current. Use Value: 0.5% VREF tolerance and 27-mV temp drift ensure ±1.2% output accuracy over full automotive temperature range. | Use Scenario: Replaces 3.3-V Zener diode in overvoltage protection circuit for 3.3-V microcontroller I/O rail. IC Role / Device Role / Timing Role: Programmable shunt clamp activated when rail exceeds 3.3 V; sinks excess current to prevent damage. Use Value: Sharp turn-on characteristic and 0.3-Ω impedance provide faster, more predictable clamping than Zener diodes with higher dynamic resistance. |
| Voltage Monitoring (Undervoltage Lockout) | Precision Constant Current Sink |
Use Scenario: Monitors 24-V battery rail in industrial PLC to trigger shutdown if voltage drops below 20 V. IC Role / Device Role / Timing Role: Comparator with integrated 2.5-V reference; REF pin biased to 2.5 V via resistor divider; CATHODE pulled high when threshold crossed. Use Value: Ultra-low 0.4-µA IREF minimizes divider power loss; 125°C rating ensures reliability in hot control cabinet environments. | Use Scenario: Sinks constant 10 mA from LED string in automotive interior lighting system. IC Role / Device Role / Timing Role: Precision current sink configured with REF-to-ANODE resistor; cathode connected to LED anode; ANODE grounded. Use Value: 80-µA Imin and 15-mA IKA rating allow stable operation across wide input voltage range (9–16 V), independent of LED forward voltage variation. |
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, but 100 µA min cathode current (vs. 80 µA), 1% VREF tolerance (vs. 0.5%), higher temp drift (36 mV Q-temp) | Less suitable for ultra-low-power or high-accuracy automotive designs requiring tighter regulation | Select TL431LIBIDBZR only if cost sensitivity outweighs accuracy and quiescent current requirements |
| ATL431LIDBZR | A-grade variant: 1% VREF tolerance (vs. 0.5%), otherwise identical electrical specs and pinout | Acceptable where ±1% output tolerance is sufficient, e.g., non-safety-critical industrial supplies | Choose ATL431LIDBZR for cost-optimized designs where 0.5% grade is unnecessary |
Compared with TL431LIBIDBZR, ATL431LIBIDBZR delivers tighter initial accuracy and lower operating current - directly improving output regulation and system efficiency; versus ATL431LIDBZR, it trades higher cost for 0.5× VREF error margin, critical in precision feedback paths.
Availability
ATL431LIBIDBZR is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, and telecom DC/DC converters requiring stable component supply with guaranteed long-term availability and automotive-grade qualification.
Supply support for ATL431LIBIDBZR 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 ATL43xLI family was designed specifically as high-accuracy, low-IQ programmable shunt regulators for secondary-side feedback in isolated switching power supplies and precision voltage/current referencing in harsh-environment applications.
FAQ
What is the minimum cathode current required for regulation in ATL431LIBIDBZR?
The ATL431LIBIDBZR requires a minimum cathode current of 80 µA (maximum specified) to maintain regulation. This value is confirmed in Section 7.4 (Recommended Operating Conditions) and Table 7.5 (Electrical Characteristics) of the SLVSDU6D datasheet. Operating below this level may result in loss of regulation or degraded accuracy. The ATL431LIBIDBZR achieves lower Imin than legacy TL431LI, enabling reduced system standby power consumption.
Does ATL431LIBIDBZR require an external compensation capacitor?
No, ATL431LIBIDBZR does not require an external compensation capacitor for stable operation in most configurations. Its internal compensation allows direct use in feedback loops of flyback converters without added components - verified in Section 10.3 and Figure 13 of the SLVSDU6D datasheet. However, when large capacitive loads (>10 nF) or specific stability margins are needed, consult the stability boundary charts to select appropriate CL values.
What is the temperature range specification for ATL431LIBIDBZR?
The ATL431LIBIDBZR is qualified for operation from −40°C to +125°C (Q-temp grade), as explicitly stated in the "Features" section and Section 10.1 of the SLVSDU6D datasheet. This extended temperature range meets AEC-Q100 stress test requirements for automotive under-hood and body control applications, distinguishing it from commercial-grade variants limited to −40°C to +85°C.
How does the pinout of ATL431LIBIDBZR differ from ATL432LIBIDBZR?
ATL431LIBIDBZR uses Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE in the SOT-23-3 (DBZ) package. ATL432LIBIDBZR has a different pinout: Pin 1 = CATHODE, Pin 2 = ANODE, Pin 3 = REF. This difference is documented in Section 6 ("Pin Configuration and Functions") of the SLVSDU6D datasheet. Interchanging them without board revision will cause functional failure - always verify pin mapping before layout or replacement.
What is the dynamic impedance of ATL431LIBIDBZR and why does it matter?
The ATL431LIBIDBZR has a typical dynamic impedance |ZKA| of 0.3 Ω at 1 mA cathode current (Section 7.5, Electrical Characteristics). This low value means the cathode voltage changes only ~0.3 mV per 1 mA load step - critical for maintaining tight output regulation in switching power supplies where feedback loop stability and transient response depend on minimal impedance-induced voltage error.
ATL431LIBIDBZR 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 ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
ATL431LIBIDBZR FAQ
1.How can I place an order for ATL431LIBIDBZR through Aetrix?
Please submit a Request for Quotation (RFQ) for ATL431LIBIDBZR 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 ATL431LIBIDBZR reliable?
The price and inventory of ATL431LIBIDBZR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ATL431LIBIDBZR is usually 5 days.
3.What payment methods are accepted for ATL431LIBIDBZR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ATL431LIBIDBZR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ATL431LIBIDBZR?
ATL431LIBIDBZR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ATL431LIBIDBZR 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 ATL431LIBIDBZR?
For technical support, including ATL431LIBIDBZR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ATL431LIBIDBZR requirements.
6.How does Aetrix verify that ATL431LIBIDBZR is sourced from the original manufacturer or authorized distributors?
All ATL431LIBIDBZR 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 ATL431LIBIDBZR meets industry standards.
7.What is the process for return or replacement of ATL431LIBIDBZR?
All ATL431LIBIDBZR units undergo pre-shipment inspection (PSI). If there is an issue with ATL431LIBIDBZR, 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 ATL431LIBIDBZR part is unused and in its original packaging.
Return procedure for ATL431LIBIDBZR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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