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Diodes Incorporated AS431AZTR-E1
- Part No.:
- AS431AZTR-E1
- Manufacturer:
- Diodes Incorporated
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
AS431AZTR-E1.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% TO92
- Quantity:
- Payment:
- Shipping:
Inventory:40,540
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Product details
Overview
AS431AZTR-E1 from Diodes Incorporated is a three-terminal adjustable precision shunt regulator with 0.5% reference voltage tolerance, 2.5V to 36V programmable output, and guaranteed thermal stability from –40°C to +125°C. It replaces Zener diodes in switching power supplies, battery chargers, and precision voltage references, featuring 0.15Ω typical dynamic impedance and 4.5mV typical reference voltage deviation over full temperature range.
For engineers reviewing the AS431AZTR-E1 datasheet, AS431AZTR-E1 pinout, AS431AZTR-E1 application, or AS431AZTR-E1 equivalent, this device serves as a stable, low-noise, capacitive-load-tolerant voltage reference for feedback loops in DC-DC converters, adapter circuits, and graphic card VRMs where tight regulation and low temperature drift are critical.
Technical Context
The AS431AZTR-E1 implements a bandgap-based precision reference core with internal error amplifier and output stage optimized for shunt regulation. Its sharp turn-on characteristic and low 20ppm/°C typical temperature coefficient enable stable operation across industrial temperature extremes without external compensation.
It operates as a two-input (REF, ANODE) / one-output (CATHODE) active shunt element, sinking 1mA–100mA cathode current while maintaining regulation at VKA ≥ VREF. The device exhibits high stability under load capacitance up to 100µF and supports both fixed and adjustable configurations via external resistor dividers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage (VREF) | 2.500 V ±0.5% - sets precise regulation threshold for feedback networks |
| Output Voltage Range | 2.5V to 36V - programmable via external resistive divider, enabling flexible system-level voltage setting |
| Dynamic Impedance (ZKA) | 0.15 Ω typical - ensures minimal output voltage perturbation under fast load transients |
| Temp. Coefficient (TC) | 20 ppm/°C typical - guarantees <±8 mV drift over –40°C to +125°C, critical for industrial-grade accuracy |
| Cathode Current Range | 1.0 mA to 100 mA - supports wide-range sink capability for diverse regulator topologies |
| Operating Temperature | –40°C to +125°C - qualified for under-hood automotive, industrial power, and embedded computing environments |
| Package | TO92 (Ammo Packing) - through-hole package with 81.9°C/W junction-to-case thermal resistance for cost-sensitive, medium-power designs |
Pinout & Package
AS431AZTR-E1 is supplied in TO92 (Ammo Packing) package: 3-pin through-hole, lead-free, RoHS-compliant, with 12.5mm body length and 2.54mm lead pitch. Pin 1 = REF, Pin 2 = CATHODE, Pin 3 = ANODE (Pin 2 internally connected to substrate and must be connected to ANODE or left open).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (REF) | Reference Input | High-impedance input sensing node; connects to resistor divider midpoint to set regulated output voltage |
| Pin 2 (CATHODE) | Regulated Output Terminal | Sinks current to maintain VKA = VREF × (1 + R1/R2); electrically tied to substrate |
| Pin 3 (ANODE) | Return Path / Ground Reference | Common return for cathode current; must be connected to system ground or low-side of feedback network |
Key Features
| Feature | Design Value |
|---|---|
| Programmable Output Voltage | 2.5V–36V via two-resistor divider - eliminates need for multiple fixed-voltage references |
| Low Temperature Deviation | 4.5 mV typical over full –40°C to +125°C range - reduces calibration burden in wide-temp applications |
| Capacitive Load Stability | Stable with up to 100 µF output capacitance - enables direct use with bulk electrolytic caps in SMPS outputs |
| Low Output Noise | Sub-10 µVRMS (typical) - preserves signal integrity in precision analog feedback paths |
| High Sink Current Capacity | 100 mA max cathode current - supports high-gain optocoupler drivers and multi-rail regulator supervision |
Applications
| Switching Power Supply Feedback | Battery Charger Regulation |
|---|---|
|
Use Scenario: Primary-side feedback loop in isolated flyback converters using optocoupler-coupled error amplification. IC Role / Device Role / Timing Role: Precision shunt reference generating stable 2.5V reference for TL431-compatible optocoupler biasing. Use Value: Enables ±1% output voltage regulation across line/load/temperature with no secondary-side controller. |
Use Scenario: Constant-voltage stage in Li-ion battery charger ICs or discrete linear charging circuits. IC Role / Device Role / Timing Role: Adjustable voltage reference setting charge termination threshold (e.g., 4.2V ±0.5% per cell). Use Value: Maintains tight voltage accuracy over ambient temperature swings, preventing overcharge and extending battery life. |
| Voltage Adapter Reference | Graphic Card VRM Monitoring |
|
Use Scenario: Universal AC-DC adapter with selectable output voltages (5V/9V/12V/15V/20V) via USB PD negotiation. IC Role / Device Role / Timing Role: Programmable reference for DAC-controlled buck converter feedback network. Use Value: Allows single hardware platform to support multiple output standards without changing reference components. |
Use Scenario: GPU voltage rail monitoring and fine-tuning in high-performance desktop graphics cards. IC Role / Device Role / Timing Role: Precision shunt element in remote-sense feedback path for 0.8–1.35V core voltage regulation. Use Value: Delivers <±5mV reference stability under transient GPU load steps, improving power delivery accuracy. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACDR | 2.5V ±1.0% reference, SOIC-8 package, higher 0.3Ω typical ZKA | Requires surface-mount layout; less accurate but widely available in legacy designs | Choose for cost-sensitive, space-constrained PCBs where ±1% tolerance is acceptable |
| KA431AZTA | 2.5V ±0.5%, TO92 package, 25ppm/°C TC, 0.2Ω ZKA, lower IKA(min) = 0.2mA | Same through-hole footprint; slightly higher tempco and impedance than AS431AZTR-E1 | Choose when sourcing flexibility is needed and minor degradation in thermal stability is acceptable |
Compared with TL431ACDR and KA431AZTA, AS431AZTR-E1 delivers tighter 0.5% initial tolerance, lower 20ppm/°C temperature coefficient, and superior 0.15Ω dynamic impedance-making it optimal for next-generation adapters and industrial power supplies demanding long-term regulation stability.
Availability
AS431AZTR-E1 is available at Aetrix Electronics and suitable for switching power supply feedback, battery charger regulation, and voltage adapter reference applications requiring stable component supply, consistent parametric performance, and long-term industrial lifecycle support.
Supply support for AS431AZTR-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 integrated circuits, specializing in high-reliability power management, signal integrity, and protection solutions for industrial, computing, and consumer markets.
The AS431 belongs to Diodes' precision reference product line, engineered specifically for high-stability shunt regulation in power conversion systems where Zener replacement, low drift, and robust capacitive-load immunity are required.
FAQ
What is the minimum cathode current required for regulation in AS431AZTR-E1?
The AS431AZTR-E1 requires a minimum cathode current of 0.4 mA to maintain regulation, with typical value of 1.0 mA. This low IKA(min) enables stable operation even in high-impedance feedback networks or low-power standby modes, reducing quiescent current overhead in energy-efficient designs.
Can AS431AZTR-E1 replace a standard Zener diode directly in existing circuits?
Yes-AS431AZTR-E1 can directly replace Zener diodes rated between 2.5V and 36V by connecting REF to the Zener cathode node, CATHODE to the original Zener anode, and ANODE to ground. Its sharp turn-on and low dynamic impedance provide superior regulation accuracy and thermal stability compared to discrete Zeners.
Does AS431AZTR-E1 require external compensation for stability?
No external compensation is required. The AS431AZTR-E1 is internally compensated and remains stable with output capacitance up to 100 µF, including aluminum electrolytic and tantalum types. This eliminates design iteration for phase margin tuning in most SMPS feedback implementations.
What is the maximum cathode voltage rating for AS431AZTR-E1?
The absolute maximum cathode-to-anode voltage (VKA) is 40 V, with recommended operating limit of 36 V. Exceeding 36 V risks exceeding power dissipation limits and degrading long-term reliability-even though the device may function momentarily at 40 V under transient conditions.
AS431AZTR-E1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Series:
- -
- Packaging:
- Cut Tape (CT)
- Product Status:
- Active
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 2.5V
- Voltage - Output (Max):
- 36 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:
- 1 mA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92
AS431AZTR-E1 FAQ
1.How can I place an order for AS431AZTR-E1 through Aetrix?
Please submit a Request for Quotation (RFQ) for AS431AZTR-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 AS431AZTR-E1 reliable?
The price and inventory of AS431AZTR-E1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AS431AZTR-E1 is usually 5 days.
3.What payment methods are accepted for AS431AZTR-E1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AS431AZTR-E1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AS431AZTR-E1?
AS431AZTR-E1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AS431AZTR-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 AS431AZTR-E1?
For technical support, including AS431AZTR-E1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AS431AZTR-E1 requirements.
6.How does Aetrix verify that AS431AZTR-E1 is sourced from the original manufacturer or authorized distributors?
All AS431AZTR-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 AS431AZTR-E1 meets industry standards.
7.What is the process for return or replacement of AS431AZTR-E1?
All AS431AZTR-E1 units undergo pre-shipment inspection (PSI). If there is an issue with AS431AZTR-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 AS431AZTR-E1 part is unused and in its original packaging.
Return procedure for AS431AZTR-E1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AS431AZTR-E1 Tags
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TL431AIDBZR
Texas Instruments
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TL431BQDBZR
Texas Instruments
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AN431AN-ATRG1
Diodes Incorporated
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LM4040CYM3-2.5-TR
Microchip Technology
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LM4040CYM3-4.1-TR
Microchip Technology
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LM4040EIM3-2.5/NOPB
Texas Instruments
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AZ431LBNTR-G1
Diodes Incorporated
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LM4040D20IDBZR
Texas Instruments
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LM4041DIM3-ADJ/NOPB
Texas Instruments
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LM4040DIM3X-2.5/NOPB
Texas Instruments
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LM4040DIM3-2.5/NOPB
Texas Instruments
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AZ431LANTR-G1
Diodes Incorporated
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