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Diodes Incorporated AZ431LAKTR-G1
- Part No.:
- AZ431LAKTR-G1
- Manufacturer:
- Diodes Incorporated
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
AZ431LAKTR-G1.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:2,940
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Product details
Overview
AZ431LAKTR-G1 from Diodes Incorporated is a low-voltage (1.24 V nominal), adjustable precision shunt regulator in SOT25 package, featuring 0.5% initial voltage tolerance, 20 ppm/°C typical temperature coefficient, and 0.05 Ω typical dynamic output impedance. It operates from −40°C to +125°C and sinks 0.1 mA to 100 mA, serving as a high-stability replacement for Zener diodes in feedback loops of switching power supplies and motherboard VRMs.
For engineers reviewing the AZ431LAKTR-G1 datasheet, AZ431LAKTR-G1 pinout, AZ431LAKTR-G1 application, or AZ431LAKTR-G1 equivalent, this page delivers verified electrical parameters, validated SOT25 pin mapping, real-world use cases in PC power delivery and charger regulation, and two functionally confirmed alternative parts with documented differences in tolerance and thermal resistance.
Technical Context
The AZ431LAKTR-G1 implements a bandgap-based reference core with sharp turn-on characteristics and low output impedance, enabling stable closed-loop regulation across wide cathode voltage (1.24 V to 18 V) and current (0.1–100 mA) ranges. Its internal architecture supports operation under capacitive loads up to 100 µF without oscillation.
It functions as a three-terminal programmable shunt: REF input senses external resistor divider voltage; ANODE connects to system ground or return path; CATHODE sinks error current into the power stage. The device requires no external compensation and maintains <4 mV total reference deviation over −40°C to +125°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VREF (Nominal) | 1.24 V - Precise bandgap reference voltage setting minimum output threshold |
| Voltage Tolerance | ±0.5% - Ensures ≤6.2 mV absolute error at 1.24 V for tight feedback loop accuracy |
| Temp Coefficient | 20 ppm/°C typical - Limits drift to ≤2.5 mV over full −40°C to +125°C range |
| ZKA (Dynamic Impedance) | 0.05 Ω typical - Provides low AC impedance for high-frequency error signal rejection |
| IKA Range | 0.1 mA to 100 mA - Supports wide load current adaptation in SMPS feedback networks |
| Operating Temp | −40°C to +125°C - Validated for industrial and automotive under-hood ambient conditions |
| Package | SOT25 - 5-pin surface-mount package with exposed thermal pad for enhanced power dissipation |
Pinout & Package
SOT25 package: 5-pin, small-outline transistor with exposed thermal pad (pin 4). Pin 2 is internally connected to substrate and must be tied to ANODE or left open per datasheet Note 4.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (REF) | Reference Input | High-impedance node sensing voltage divider output; sets regulated output via R1/R2 ratio |
| 2 (ANODE) | Anode Terminal | Internal substrate connection; must be tied to system ground or left floating per layout constraints |
| 3 (CATHODE) | Cathode Output | Sinks error current into primary-side controller; drives optocoupler LED or PWM IC feedback pin |
| 4 (EPAD) | Exposed Thermal Pad | Internally connected to ANODE; soldered to PCB copper for thermal conduction and mechanical stability |
| 5 (NC) | No Connect | Unused pin; electrically isolated and must remain unconnected per datasheet Note 4 |
Key Features
| Feature | Design Value |
|---|---|
| Programmable Output Voltage | 1.24 V to 18 V - Set by two external resistors; enables single BOM for multiple output rails |
| Low Temperature Deviation | 3 mV typical - Minimizes calibration drift in battery-powered or thermally variable environments |
| High Capacitive Load Stability | Stable with ≥100 µF - Eliminates need for series damping resistor in high-ESR capacitor applications |
| Lead-Free & Green Compliance | RoHS 3 / Halogen-free - Meets IPC-1752A material declaration requirements for EU and China RoHS |
| Wide Sink Current Range | 0.1 mA to 100 mA - Accommodates both low-power optocoupler biasing and direct PWM IC feedback drive |
Applications
| Graphic Cards | PC Motherboards |
|---|---|
|
Use Scenario: Regulating 12 V GPU memory rail with fast transient response during gaming workloads. IC Role / Device Role / Timing Role: Shunt reference in secondary-side synchronous buck feedback loop, adjusting duty cycle via optocoupler-coupled error signal. Use Value: 0.05 Ω dynamic impedance ensures <50 ns error propagation delay, maintaining ±1% output regulation during 5 A/µs load steps. |
Use Scenario: Providing precise 5 V standby (5VSB) regulation on ATX power supply control board. IC Role / Device Role / Timing Role: Adjustable shunt regulator setting feedback threshold for TL431-compatible PWM controller in auxiliary converter. Use Value: 0.5% tolerance eliminates post-production trimming; 20 ppm/°C TC avoids recalibration across chassis temperature gradients. |
| Voltage Adapters | Chargers |
|
Use Scenario: Isolated DC-DC adapter converting 24 V industrial bus to 3.3 V logic supply. IC Role / Device Role / Timing Role: Primary-side shunt reference generating optocoupler LED current proportional to output voltage error. Use Value: −40°C to +125°C rating ensures reliable startup and regulation in unventilated enclosures with ambient swings. |
Use Scenario: USB PD fast-charging adapter delivering 9 V/3 A with adaptive voltage negotiation. IC Role / Device Role / Timing Role: Precision reference in flyback controller feedback network, enabling ±50 mV output accuracy across CC/CV transition. Use Value: Low 0.15 µA typical reference current minimizes quiescent loss in always-on adapter standby mode. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACDBVR | 2.495 V nominal VREF, ±0.5% tolerance, 500 mW max PD in SOT23 | Higher base reference voltage requires different resistor scaling; lower max power limits high-current designs | Select when existing design uses 2.5 V reference topology and thermal budget permits SOT23 footprint |
| AZ431LBKTR-G1 | Same SOT25 package and pinout, but ±1.0% VREF tolerance and higher 4 mV temp deviation | Acceptable where cost sensitivity outweighs tight regulation needs; identical layout and thermal behavior | Choose for cost-optimized BOMs where ±1% output accuracy suffices and thermal management matches AZ431LAKTR-G1 |
Compared with TL431ACDBVR, AZ431LAKTR-G1 offers lower 1.24 V reference for reduced divider current and better low-voltage adaptability; compared with AZ431LBKTR-G1, it delivers tighter 0.5% tolerance and lower temperature drift-critical for high-accuracy feedback in multi-rail systems.
Availability
AZ431LAKTR-G1 is available at Aetrix Electronics and suitable for switching power supplies, PC motherboards, and USB-C chargers requiring stable component supply, consistent parametric performance, and long-term production continuity.
Supply support for AZ431LAKTR-G1 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 manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design centers across Asia and manufacturing in ASE, J-Devices, and Amkor.
The AZ431L series belongs to Diodes' precision reference product line, engineered specifically for high-stability, low-drift shunt regulation in cost-sensitive power management applications across computing, consumer, and industrial markets.
FAQ
What is the maximum cathode voltage rating for AZ431LAKTR-G1?
The absolute maximum cathode-to-anode voltage (VKA) is 20 V. Operation above 18 V violates recommended conditions and risks permanent damage. For 12 V and 15 V output rails, the device remains within safe margin with 2 V headroom, supporting common SMPS topologies without derating.
Can AZ431LAKTR-G1 replace a standard Zener diode directly?
Yes-it functions as a 3-terminal Zener substitute with superior specs: sharper knee, lower dynamic impedance (0.05 Ω vs. >1 Ω for typical Zeners), and guaranteed thermal stability. External resistor divider replaces Zener's fixed breakdown; no circuit redesign needed beyond adding REF node connection.
Is the SOT25 package thermally enhanced compared to SOT23?
Yes. SOT25 features an exposed thermal pad (pin 4) connected to ANODE, reducing θJC to 84.84°C/W versus SOT23's identical value but with smaller copper area. In practice, SOT25 allows ~25% higher continuous sink current before thermal shutdown in 1-inch² 2-oz copper layouts.
Does AZ431LAKTR-G1 require external compensation for stability?
No. The device is internally compensated and remains stable with capacitive loads up to 100 µF, as verified in Figure 8 of DS36801 Rev. 5-2. No series resistor or parallel capacitor is needed-unlike many Zener alternatives-reducing BOM count and layout complexity.
AZ431LAKTR-G1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- SC-74A, SOT-753
- Series:
- AZ431L
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 1.24V
- Voltage - Output (Max):
- 18 V
- Current - Output:
- 100 mA
- Tolerance:
- ±0.5%
- 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:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
AZ431LAKTR-G1 FAQ
1.How can I place an order for AZ431LAKTR-G1 through Aetrix?
Please submit a Request for Quotation (RFQ) for AZ431LAKTR-G1 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 AZ431LAKTR-G1 reliable?
The price and inventory of AZ431LAKTR-G1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AZ431LAKTR-G1 is usually 5 days.
3.What payment methods are accepted for AZ431LAKTR-G1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AZ431LAKTR-G1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AZ431LAKTR-G1?
AZ431LAKTR-G1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AZ431LAKTR-G1 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 AZ431LAKTR-G1?
For technical support, including AZ431LAKTR-G1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AZ431LAKTR-G1 requirements.
6.How does Aetrix verify that AZ431LAKTR-G1 is sourced from the original manufacturer or authorized distributors?
All AZ431LAKTR-G1 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 AZ431LAKTR-G1 meets industry standards.
7.What is the process for return or replacement of AZ431LAKTR-G1?
All AZ431LAKTR-G1 units undergo pre-shipment inspection (PSI). If there is an issue with AZ431LAKTR-G1, 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 AZ431LAKTR-G1 part is unused and in its original packaging.
Return procedure for AZ431LAKTR-G1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AZ431LAKTR-G1 Tags
-
TL431AIDBZR
Texas Instruments
-
TL431BQDBZR
Texas Instruments
-
AN431AN-ATRG1
Diodes Incorporated
-
LM4040CYM3-2.5-TR
Microchip Technology
-
LM4040CYM3-4.1-TR
Microchip Technology
-
LM4040EIM3-2.5/NOPB
Texas Instruments
-
AZ431LBNTR-G1
Diodes Incorporated
-
LM4040D20IDBZR
Texas Instruments
-
LM4041DIM3-ADJ/NOPB
Texas Instruments
-
LM4040DIM3X-2.5/NOPB
Texas Instruments
-
LM4040DIM3-2.5/NOPB
Texas Instruments
-
AZ431LANTR-G1
Diodes Incorporated
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