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Diodes Incorporated AS431ARTR-G1
- Part No.:
- AS431ARTR-G1
- Manufacturer:
- Diodes Incorporated
- Category:
- Voltage Reference
- Package:
- TO-243AA
- Datasheet:
-
AS431ARTR-G1.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT89-3
- Quantity:
- Payment:
- Shipping:
Inventory:895
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Product details
Overview
AS431ARTR-G1 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, delivering 0.15Ω dynamic impedance and 4.5mV typical reference deviation over full temperature range.
For engineers reviewing the AS431ARTR-G1 datasheet, AS431ARTR-G1 pinout, AS431ARTR-G1 application, or AS431ARTR-G1 equivalent, this device serves as a high-stability, low-noise, capacitive-load-tolerant voltage reference for feedback loops in DC-DC converters, adapter circuits, and current-source designs requiring tight regulation and minimal drift.
Technical Context
The AS431ARTR-G1 implements a bandgap-based precision reference core with sharp turn-on characteristics and low output impedance. Its internal architecture enables stable operation under capacitive loads up to 100µF without oscillation across cathode voltages from 3.5V to 15V.
It operates as a two-input (REF, ANODE) / one-output (CATHODE) shunt regulator with sink current capability from 1mA to 100mA. The reference input draws only 0.7µA typical current, enabling high-impedance resistor-divider networks while maintaining <1.2µA total reference current variation over −40°C to +125°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.500V ±0.5% - sets precise regulation threshold for external resistor divider |
| Output Voltage Range | 2.5V to 36V - programmable via external resistors without internal scaling limitations |
| Dynamic Impedance | 0.15Ω typical - ensures minimal output voltage shift under load transients |
| Tempco | 20ppm/°C typical - guarantees ≤16mV total reference drift from −40°C to +125°C |
| Sink Current Range | 1mA to 100mA - supports direct feedback control in medium-power SMPS and linear regulators |
| Operating Temp | −40°C to +125°C - qualified for automotive under-hood and industrial ambient environments |
| Cathode Voltage Max | 40V absolute max - allows safe operation with 36V regulated output plus margin |
Pinout & Package
AS431ARTR-G1 is packaged in RoHS-compliant, halogen-free SOT23 (3-pin, 2.9mm × 1.3mm), with pin 1 = REF, pin 2 = CATHODE, pin 3 = ANODE. Pin 2 is electrically connected to the die substrate and must be tied to the cathode node.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (REF) | Reference Input | High-impedance node sensing voltage divider midpoint; draws ≤4µA at 25°C |
| Pin 2 (CATHODE) | Output Terminal | Sinks regulated current; connects to SMPS feedback node or error amplifier inverter input |
| Pin 3 (ANODE) | Return Path | Connects to system ground or low-side return; forms closed shunt loop with REF and CATHODE |
Key Features
| Feature | Design Value |
|---|---|
| Programmable Output | 2.5V–36V set by two external resistors - eliminates need for multiple fixed-voltage references |
| Capacitive Load Stability | No oscillation with ≥100µF output capacitance - simplifies EMI filtering in compact adapters |
| Low Reference Current | 0.7µA typical - reduces divider power loss and improves efficiency in battery-powered systems |
| Thermal Stability | 4.5mV typical drift over −40°C to +125°C - enables single-point calibration in wide-temp applications |
| Green Packaging | SOT23 with halogen/antimony-free molding compound - meets IPC-1752A Class 3 environmental compliance |
Applications
| Switching Power Supply | Battery Charger |
|---|---|
Use Scenario: Feedback voltage reference in isolated flyback or forward converter secondary-side regulation. IC Role / Device Role / Timing Role: Shunt regulator providing precise 2.5V reference to optocoupler input, enabling accurate primary-side voltage control. Use Value: Enables ±1% output regulation across line/load/temperature with no secondary-side controller IC. |
Use Scenario: Constant-voltage stage reference in multi-cell Li-ion charger IC feedback loop. IC Role / Device Role / Timing Role: Adjustable reference setting charge termination voltage (e.g., 4.2V/cell) via resistor network. Use Value: Supports cell-count flexibility and aging compensation without changing BOM. |
| Voltage Adapter | Graphic Card VRM |
Use Scenario: Low-cost AC-DC adapter output regulation where Zener diodes lack stability. IC Role / Device Role / Timing Role: Precision shunt element replacing 3.3V/5V Zener in offline SMPS feedback path. Use Value: Reduces output voltage drift from ±5% to ±0.5% over temperature and life. |
Use Scenario: Remote sensing reference for GPU core voltage (VDDC) rail in desktop graphics cards. IC Role / Device Role / Timing Role: High-stability reference feeding multiphase buck controller error amplifier. Use Value: Maintains <±10mV reference accuracy under 10A load steps and 85°C board temperature. |
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 | 2.495V ±1% reference, 37Ω higher dynamic impedance (0.52Ω typ), 50ppm/°C tempco | Lower accuracy and stability limit use in <±0.5% output regulation systems | Select when cost sensitivity outweighs precision requirements and thermal drift budget allows ≥2× AS431ARTR-G1's drift |
| KA431AZTA | 2.5V ±2% reference, TO92 package, 100ppm/°C tempco, 1.5Ω dynamic impedance | Not suitable for surface-mount designs or high-accuracy feedback loops | Choose only for through-hole prototyping or legacy replacements where SMT footprint and 0.5% tolerance are not required |
Compared with TL431ACDR and KA431AZTA, AS431ARTR-G1 delivers 2× tighter reference tolerance, 3.5× lower dynamic impedance, and 5× better temperature coefficient-enabling higher loop gain and improved transient response in digitally controlled power stages.
Availability
AS431ARTR-G1 is available at Aetrix Electronics and suitable for switching power supply design, battery charging systems, and voltage adapter development requiring stable component supply, RoHS/Green compliance, and long-term production continuity.
Supply support for AS431ARTR-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, 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-accuracy, thermally stable shunt regulation in space-constrained power conversion applications where Zener diodes fall short on drift and noise performance.
FAQ
What is the minimum cathode current required for regulation in AS431ARTR-G1?
The AS431ARTR-G1 requires a minimum cathode current of 0.4mA to maintain regulation, with typical operation starting reliably at 1.0mA. This low turn-on threshold enables stable feedback in low-power standby modes and ultra-low-quiescent-current designs where traditional TL431 variants demand ≥1mA.
Can AS431ARTR-G1 replace a standard Zener diode directly in existing circuits?
Yes-AS431ARTR-G1 can directly replace Zener diodes rated between 2.5V and 36V using identical resistor-divider topology. Its 3-pin SOT23 footprint matches common Zener packages, and its sharp turn-on eliminates the soft knee behavior of Zeners, improving regulation accuracy without circuit redesign.
Does AS431ARTR-G1 require an external capacitor for stability?
No external capacitor is required for stability. The AS431ARTR-G1 remains oscillation-free with output capacitances up to 100µF across cathode voltages from 3.5V to 15V, verified per datasheet Figure 11. This eliminates stability-compensation components needed with many competing shunt regulators.
What is the thermal resistance (θJA) of AS431ARTR-G1 in SOT23 package?
The junction-to-ambient thermal resistance (θJA) for AS431ARTR-G1 in SOT23 is 290°C/W under standard JEDEC 51-7 PCB conditions (1-inch² copper pad). With 2cm² copper pour, θJA drops to ~135°C/W, enabling 100mA continuous operation at +85°C ambient without derating.
AS431ARTR-G1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- TO-243AA
- 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:
- 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:
- Surface Mount
- Supplier Device Package:
- SOT-89-3
AS431ARTR-G1 FAQ
1.How can I place an order for AS431ARTR-G1 through Aetrix?
Please submit a Request for Quotation (RFQ) for AS431ARTR-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 AS431ARTR-G1 reliable?
The price and inventory of AS431ARTR-G1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AS431ARTR-G1 is usually 5 days.
3.What payment methods are accepted for AS431ARTR-G1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AS431ARTR-G1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AS431ARTR-G1?
AS431ARTR-G1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AS431ARTR-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 AS431ARTR-G1?
For technical support, including AS431ARTR-G1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AS431ARTR-G1 requirements.
6.How does Aetrix verify that AS431ARTR-G1 is sourced from the original manufacturer or authorized distributors?
All AS431ARTR-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 AS431ARTR-G1 meets industry standards.
7.What is the process for return or replacement of AS431ARTR-G1?
All AS431ARTR-G1 units undergo pre-shipment inspection (PSI). If there is an issue with AS431ARTR-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 AS431ARTR-G1 part is unused and in its original packaging.
Return procedure for AS431ARTR-G1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AS431ARTR-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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