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Diodes Incorporated AZ431LBZTR-E1
- Part No.:
- AZ431LBZTR-E1
- Manufacturer:
- Diodes Incorporated
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
AZ431LBZTR-E1.pdf
- Description:
- IC VREF SHUNT ADJ 1% TO92
- Quantity:
- Payment:
- Shipping:
Inventory:496
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Product details
Overview
AZ431LBZTR-E1 from Diodes Incorporated is a 1.0% tolerance, low-voltage (1.24 V nominal) adjustable precision shunt regulator in SOT23 package, designed for voltage reference and feedback regulation in switching power supplies, PC motherboards, and chargers. It delivers stable 1.24 V reference with ±10 mV max deviation over –40°C to +125°C, 0.05 Ω typical dynamic impedance, and 0.1–100 mA sink current capability.
For engineers reviewing the AZ431LBZTR-E1 datasheet, AZ431LBZTR-E1 pinout, AZ431LBZTR-E1 application, or AZ431LBZTR-E1 equivalent, this page provides verified pin assignments, thermal resistance (84.84°C/W), cathode voltage range (1.24–18 V), temperature coefficient (20 ppm/°C typical), and real-world use cases in precision 5 V regulators and PWM converters.
Technical Context
The AZ431LBZTR-E1 functions as a three-terminal adjustable shunt reference with internal bandgap core and high-gain error amplifier. Its sharp turn-on and low output impedance enable stable regulation under capacitive loads up to 100 µF without oscillation, as confirmed by stability plots across 1.8 kΩ load and 100 kHz frequency.
It operates as a programmable voltage node where REF pin senses divided cathode voltage, ANODE connects to system ground or return path, and CATHODE sinks current into the regulated rail. The device maintains regulation down to 55 µA minimum cathode current and exhibits <0.1 µA off-state leakage at 18 V cathode voltage.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VREF | 1.240 V nominal; sets precise regulation point with ±1.252 V max at 1.0% tolerance |
| ∆VREF (–40°C to +125°C) | ±4 mV max deviation; ensures stable reference across automotive and industrial ambient ranges |
| ZKA | 0.05 Ω typical dynamic impedance; minimizes output voltage shift under load transients |
| IKA Range | 0.1–100 mA sink current; supports direct feedback loop drive without external buffer |
| θJC | 84.84°C/W junction-to-case thermal resistance; enables reliable operation at 370 mW PD in SOT23 |
| Temp Coefficient | 20 ppm/°C typical; translates to <0.25 mV/°C drift for 12.5 V output configuration |
| VKA Max | 20 V absolute max cathode voltage; allows safe operation in 18 V programmable output designs |
Pinout & Package
AZ431LBZTR-E1 is housed in a RoHS-compliant, lead-free SOT23-3 package (JEDEC TO-236AB), with 2.3 mm × 1.3 mm footprint and 1.1 mm height. Thermal pad is not present; heat dissipation relies on copper pour connected to ANODE (Pin 2).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (CATHODE) | Current sink terminal | Connects to regulated rail; sinks up to 100 mA to maintain VREF at divider node |
| Pin 2 (ANODE) | Ground/reference return | Must be tied to system ground or low-impedance return path; internally bonded to substrate |
| Pin 3 (REF) | Reference input | Senses voltage divider output; regulates when divider equals 1.24 V; draws only 0.4 µA typ |
Key Features
| Feature | Design Value |
|---|---|
| Programmable output range | 1.24 V to 18 V via two-resistor divider - enables single BOM for multiple output rails |
| Capacitive load stability | Stable with ≥100 µF output capacitance - eliminates need for series damping resistor in SMPS feedback |
| Low temperature drift | ±4 mV max over full –40°C to +125°C range - reduces calibration burden in wide-temp applications |
| High sink current capacity | 100 mA max cathode current - directly drives optocoupler LEDs or TL431 replacement circuits |
| Low noise & impedance | 0.05 Ω dynamic impedance and low µV/√Hz noise - preserves feedback loop accuracy in precision converters |
Applications
| Graphic Cards | PC Motherboards |
|---|---|
Use Scenario: Voltage regulation for GPU memory VRMs and auxiliary rails. IC Role / Device Role / Timing Role: Shunt reference in isolated feedback loop of multiphase buck converters. Use Value: Enables tight 0.5% output tolerance across –40°C to +105°C GPU junction temp range using minimal external components. |
Use Scenario: Core voltage reference for CPU VDDIO and chipset power sequencing. IC Role / Device Role / Timing Role: Adjustable reference for digital PWM controllers managing 1.05 V, 1.2 V, and 1.8 V rails. Use Value: Delivers stable 1.24 V reference with <20 ppm/°C drift, reducing need for trim resistors in high-volume motherboard production. |
| Voltage Adapters | Switching Power Supplies |
Use Scenario: Universal AC/DC adapter with selectable 5 V / 9 V / 12 V outputs. IC Role / Device Role / Timing Role: Programmable shunt reference setting output via rotary switch-selected resistor network. Use Value: Single AZ431LBZTR-E1 replaces three fixed zeners, cutting BOM cost and PCB area while maintaining ±1% output accuracy. |
Use Scenario: Secondary-side feedback in 30 W offline flyback converter. IC Role / Device Role / Timing Role: Precision reference driving optocoupler LED to regulate primary-side controller. Use Value: Achieves <±1.5% cross-regulation across multiple outputs due to low 0.05 Ω dynamic impedance and sharp turn-on. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BIDBZR | 2.5 V fixed reference; requires external resistor divider to set 1.24 V equivalent; higher 0.2 Ω ZKA | Not suitable for direct 1.24 V reference; needs redesign of feedback network | Select only if legacy TL431 footprint reuse is mandatory and 1.24 V must be synthesized |
| AS431ART-E1 | Same 1.24 V base, but 2% tolerance and 50 ppm/°C tempco; SOT23-3 pinout identical | Acceptable for cost-sensitive consumer adapters where ±2% output tolerance is allowed | Choose for non-critical applications where tighter tolerance and lower drift are not required |
Compared with TL431BIDBZR, AZ431LBZTR-E1 eliminates external scaling resistors for 1.24 V operation and improves dynamic regulation by 4× lower impedance; versus AS431ART-E1, it delivers 2× tighter tolerance and 2.5× better temperature stability, justifying premium use in industrial and computing power rails.
Availability
AZ431LBZTR-E1 is available at Aetrix Electronics and suitable for switching power supplies, PC motherboards, and voltage adapters requiring stable component supply, consistent RoHS/Green compliance, and long-term industrial lifecycle support.
Supply support for AZ431LBZTR-E1 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
Diodes Incorporated is a global semiconductor manufacturer specializing in discrete, analog, and mixed-signal solutions for power management, signal integrity, and connectivity applications.
AZ431LBZTR-E1 belongs to the AZ431L precision shunt regulator product line, engineered for high-stability voltage reference in space-constrained, thermally demanding power systems such as server PSUs and graphics cards.
FAQ
What is the minimum cathode current required for regulation in AZ431LBZTR-E1?
The AZ431LBZTR-E1 requires a minimum cathode current of 55 µA to maintain regulation at 25°C, rising to 80 µA across the full –40°C to +125°C operating range. This value is specified in the Electrical Characteristics table under IKA (Min) and must be met by the feedback network's total current draw to ensure stable reference behavior.
Can AZ431LBZTR-E1 replace a standard 3.3 V Zener diode in a linear regulator circuit?
No - AZ431LBZTR-E1 is not a drop-in Zener replacement for 3.3 V operation. Its reference voltage is fixed at 1.24 V; to achieve 3.3 V output, an external resistor divider must be used between cathode and reference pins. Direct 3.3 V Zener substitution would require a different part, such as AZ432L or TL432.
Is AZ431LBZTR-E1 qualified for automotive applications per AEC-Q100?
No - AZ431LBZTR-E1 is not AEC-Q100 qualified. The datasheet explicitly states that automotive-grade variants require separate qualification and PPAP capability, and users must contact Diodes directly for such parts. This device is intended for commercial and industrial applications only.
What is the maximum power dissipation for AZ431LBZTR-E1 in SOT23 package?
The maximum power dissipation for AZ431LBZTR-E1 in SOT23 is 370 mW at TA = 25°C, as stated in the Absolute Maximum Ratings table. Derating is required above 25°C at 4.6 mW/°C based on its 84.84°C/W junction-to-case thermal resistance and typical board layout conditions.
AZ431LBZTR-E1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Series:
- AZ431L
- Packaging:
- Cut Tape (CT)
- Product Status:
- Obsolete
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 1.24V
- Voltage - Output (Max):
- 18 V
- Current - Output:
- 100 mA
- Tolerance:
- ±1%
- Temperature Coefficient:
- 20ppm/°C Typical
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 80 µA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92
AZ431LBZTR-E1 FAQ
1.How can I place an order for AZ431LBZTR-E1 through Aetrix?
Please submit a Request for Quotation (RFQ) for AZ431LBZTR-E1 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 AZ431LBZTR-E1 reliable?
The price and inventory of AZ431LBZTR-E1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AZ431LBZTR-E1 is usually 5 days.
3.What payment methods are accepted for AZ431LBZTR-E1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AZ431LBZTR-E1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AZ431LBZTR-E1?
AZ431LBZTR-E1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AZ431LBZTR-E1 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 AZ431LBZTR-E1?
For technical support, including AZ431LBZTR-E1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AZ431LBZTR-E1 requirements.
6.How does Aetrix verify that AZ431LBZTR-E1 is sourced from the original manufacturer or authorized distributors?
All AZ431LBZTR-E1 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 AZ431LBZTR-E1 meets industry standards.
7.What is the process for return or replacement of AZ431LBZTR-E1?
All AZ431LBZTR-E1 units undergo pre-shipment inspection (PSI). If there is an issue with AZ431LBZTR-E1, 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 AZ431LBZTR-E1 part is unused and in its original packaging.
Return procedure for AZ431LBZTR-E1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AZ431LBZTR-E1 Tags
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TL431AIDBZR
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TL431BQDBZR
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AN431AN-ATRG1
Diodes Incorporated
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LM4040CYM3-2.5-TR
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LM4040CYM3-4.1-TR
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LM4040EIM3-2.5/NOPB
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AZ431LBNTR-G1
Diodes Incorporated
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LM4040D20IDBZR
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LM4041DIM3-ADJ/NOPB
Texas Instruments
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LM4040DIM3X-2.5/NOPB
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LM4040DIM3-2.5/NOPB
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AZ431LANTR-G1
Diodes Incorporated
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