My Inquiry
My Account
Diodes Incorporated AZ431LBKTR-E1
- Part No.:
- AZ431LBKTR-E1
- Manufacturer:
- Diodes Incorporated
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
AZ431LBKTR-E1.pdf
- Description:
- IC VREF SHUNT ADJ 1% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:2,759
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AZ431LBKTR-E1 from Diodes Incorporated is a 1.0% tolerance, adjustable precision shunt voltage reference IC in SOT25 package, designed as a low-voltage (1.24V–18V) replacement for Zener diodes in feedback loops of switching power supplies, PC motherboards, and chargers. It delivers 0.05Ω typical dynamic impedance, ±4mV max reference voltage deviation over –40°C to +125°C, and supports sink current from 0.1mA to 100mA.
For engineers reviewing the AZ431LBKTR-E1 datasheet, AZ431LBKTR-E1 pinout, AZ431LBKTR-E1 application, or AZ431LBKTR-E1 equivalent, this page provides verified electrical parameters, thermal performance data, package-specific layout guidance, and validated alternative options for stable reference design in industrial and computing power systems.
Technical Context
The AZ431LBKTR-E1 implements a bandgap-based two-terminal shunt regulator architecture with internal reference and error amplifier, operating as a programmable 3-terminal device (REF, ANODE, CATHODE). Its sharp turn-on characteristic and low 20ppm/°C temperature coefficient enable precise regulation across wide ambient ranges.
It functions exclusively in shunt mode: cathode connects to regulated rail, anode to ground or return path, and reference pin sets output via resistor divider. No external compensation is required for stability with capacitive loads up to 10µF, per test data showing stable operation at 100kHz with 1.8kΩ series resistance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VREF | 1.240V nominal, ±1.0% tolerance (1.228–1.252V) - defines minimum setpoint accuracy for feedback networks |
| ∆VREF (–40°C to +125°C) | ±4mV max deviation - ensures <±0.33% full-range drift for high-temperature motherboard designs |
| ZKA (Dynamic Impedance) | 0.05Ω typical (≤0.15Ω max) - maintains <1mV output variation under 100mA load transients |
| IKA Range | 0.1mA to 100mA sink capability - supports light-load standby and high-current regulation without external transistor |
| θJC (SOT25) | 84.84°C/W junction-to-case - enables 370mW power dissipation at ≤125°C ambient with minimal heatsinking |
| Operating Temp | –40°C to +125°C - qualified for extended industrial and embedded computing environments |
| Package | SOT25 - 5-pin surface-mount footprint with exposed pad option; compatible with standard reflow profiles |
Pinout & Package
SOT25 package: 5-pin, small-outline transistor with heat-dissipating tab; pin 2 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 setting output voltage via external R1/R2 divider; draws only 0.15–0.4µA |
| 2 (ANODE) | Anode Terminal | Internally bonded to substrate; must connect to system ground or remain floating - not used as signal path |
| 3 (CATHODE) | Cathode Output | Regulated output node; sinks current into this pin to maintain VREF × (1 + R1/R2) at cathode |
| 4 (NC) | No Connect | Unused pin; electrically isolated - no routing or soldering required |
| 5 (NC) | No Connect | Unused pin; electrically isolated - no routing or soldering required |
Key Features
| Feature | Design Value |
|---|---|
| Programmable Output Voltage | 1.24V to 18V via two external resistors - eliminates need for multiple fixed-reference SKUs |
| Capacitive Load Stability | Stable with ≥10µF output capacitance - removes need for external compensation in adapter applications |
| Low Temperature Coefficient | 20ppm/°C typical - reduces calibration drift in battery-charger feedback paths over temperature |
| Low Dynamic Output Resistance | 0.05Ω typical - minimizes output voltage sag during fast load steps in CPU VRMs |
| Wide Sink Current Range | 0.1mA to 100mA - supports both ultra-low-power standby and high-current PWM controller biasing |
Applications
| Graphic Cards | PC Motherboards |
|---|---|
Use Scenario: Precision 1.2V GPU core voltage regulation using PWM controller feedback loop. IC Role / Device Role / Timing Role: Shunt reference providing stable 1.24V基准 for error amplifier comparison. Use Value: Enables ±1% output accuracy across –40°C to +105°C GPU junction range without trimming. |
Use Scenario: 3.3V and 5V auxiliary rail regulation on ATX motherboard VRM circuits. IC Role / Device Role / Timing Role: Adjustable reference setting feedback threshold for synchronous buck controllers. Use Value: Replaces discrete Zener + op-amp solutions, reducing BOM count by 3 components per rail. |
| Voltage Adapters | Switching Power Supplies |
Use Scenario: Universal-input 12V/24V DC-DC adapter with selectable output via front-panel potentiometer. IC Role / Device Role / Timing Role: Programmable reference enabling user-adjustable output without firmware change. Use Value: Supports single-hardware platform for multiple output voltages (5V–15V) with <0.5% line/load regulation. |
Use Scenario: Secondary-side feedback in isolated flyback converters for industrial AC/DC modules. IC Role / Device Role / Timing Role: Isolated shunt reference referenced to secondary ground, driving optocoupler LED. Use Value: Achieves <±2% total output regulation across input line (85–265VAC) and load (10–100%) variations. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BIDBVR | 0.5% initial tolerance, higher 0.2Ω dynamic impedance, SOT23-6 package | Requires larger PCB area; less suitable for high-transient current rails due to higher ZKA | Select when tighter initial accuracy outweighs transient response needs and space permits SOT23-6 layout |
| AS431ATBZTR-G1 | Same 1.0% tolerance, but 0.1Ω max ZKA, TO92 package with higher θJA | Through-hole mounting; limited to ≤50mA continuous sink due to thermal resistance (140.8°C/W) | Choose for legacy through-hole designs or cost-sensitive non-SMT production where thermal derating is acceptable |
Compared with TL431BIDBVR and AS431ATBZTR-G1, the AZ431LBKTR-E1 offers superior dynamic impedance (0.05Ω vs. 0.2Ω/0.1Ω) and optimized SOT25 thermal performance (84.8°C/W), making it preferred for compact, high-current, thermally constrained power feedback designs.
Availability
AZ431LBKTR-E1 is available at Aetrix Electronics and suitable for switching power supplies, PC motherboards, and voltage adapters requiring stable component supply, RoHS-compliant sourcing, and production-ready tape-and-reel packaging.
Supply support for AZ431LBKTR-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 manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management, signal integrity, and protection solutions for industrial, computing, and consumer markets.
The AZ431L series belongs to Diodes' precision reference product line, engineered specifically for replacing Zener diodes in feedback networks of DC-DC converters and voltage regulators where accuracy, thermal stability, and low output impedance are critical.
FAQ
What is the minimum cathode current required for regulation in AZ431LBKTR-E1?
The AZ431LBKTR-E1 requires a minimum cathode current of 55µA (typical) to maintain regulation, with 80µA specified as maximum under worst-case conditions. This low IKA(Min) allows use in ultra-low-power standby circuits where bias current must stay below 100µA while preserving reference accuracy.
Can AZ431LBKTR-E1 replace a standard 3.3V Zener diode directly?
Yes - configure R1 and R2 to set VOUT = 3.3V using VREF × (1 + R1/R2), with R2 = 10kΩ and R1 ≈ 16.5kΩ. Unlike Zeners, it provides 0.05Ω dynamic impedance and ±4mV temperature drift over –40°C to +125°C, delivering significantly tighter regulation under varying load and temperature.
Is pin 2 (ANODE) required to be connected in SOT25 package?
No - per datasheet Note 4, pin 2 is internally attached to the substrate and must either be connected to the ANODE node (system ground) or left unconnected (open). It is not a functional signal pin and must never be tied to voltage rails or left floating in a way that creates parasitic coupling.
Does AZ431LBKTR-E1 support automotive-grade qualification?
No - AZ431LBKTR-E1 is not AEC-Q100 qualified. Diodes offers automotive-grade variants (e.g., AZ431LxxTR-AE) with PPAP documentation and IATF 16949 manufacturing, but this specific part (E1 suffix) is industrial-grade only, rated for –40°C to +125°C operation without automotive change control or stress testing.
AZ431LBKTR-E1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- SC-74A, SOT-753
- Series:
- AZ431L
- Packaging:
- Tape & Reel (TR)
- 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:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
AZ431LBKTR-E1 FAQ
1.How can I place an order for AZ431LBKTR-E1 through Aetrix?
Please submit a Request for Quotation (RFQ) for AZ431LBKTR-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 AZ431LBKTR-E1 reliable?
The price and inventory of AZ431LBKTR-E1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AZ431LBKTR-E1 is usually 5 days.
3.What payment methods are accepted for AZ431LBKTR-E1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AZ431LBKTR-E1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AZ431LBKTR-E1?
AZ431LBKTR-E1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AZ431LBKTR-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 AZ431LBKTR-E1?
For technical support, including AZ431LBKTR-E1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AZ431LBKTR-E1 requirements.
6.How does Aetrix verify that AZ431LBKTR-E1 is sourced from the original manufacturer or authorized distributors?
All AZ431LBKTR-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 AZ431LBKTR-E1 meets industry standards.
7.What is the process for return or replacement of AZ431LBKTR-E1?
All AZ431LBKTR-E1 units undergo pre-shipment inspection (PSI). If there is an issue with AZ431LBKTR-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 AZ431LBKTR-E1 part is unused and in its original packaging.
Return procedure for AZ431LBKTR-E1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AZ431LBKTR-E1 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
Tech Hub
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…
Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…
Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.
18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…
Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…
Product Change Notification guide for electronic components, covering PCN meaning, PCN vs PDN/EOL, common change types, risk levels, form-fit-function review, engineering validation, BOM control, LTB/L…
A practical guide to blend door actuators, covering HVAC function, symptoms, location, AC and heater issues, reset and calibration, replacement cost, electrical diagnosis, compatibility checks, and rep…
