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Diodes Incorporated AP431SARTR-G1
- Part No.:
- AP431SARTR-G1
- Manufacturer:
- Diodes Incorporated
- Category:
- Voltage Reference
- Package:
- TO-243AA
- Datasheet:
-
AP431SARTR-G1.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT89-3
- Quantity:
- Payment:
- Shipping:
Inventory:628
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Product details
Overview
AP431SARTR-G1 from Diodes Incorporated is a 3-terminal adjustable precision shunt regulator with 0.5% initial reference voltage tolerance (2.495V), low 50μA typical minimum cathode current for regulation, 0.1Ω typical dynamic impedance, and operation up to 36V cathode voltage - used as a Zener diode replacement in feedback loops of switching power supplies and USB-C chargers.
For engineers reviewing the AP431SARTR-G1 datasheet, AP431SARTR-G1 pinout, AP431SARTR-G1 application, or AP431SARTR-G1 equivalent, this device supports precise voltage setting from 2.495V to 36V, delivers stable regulation under capacitive loads up to 100μF, and maintains ±11mV reference deviation across –40°C to +125°C.
Technical Context
The AP431SARTR-G1 implements a bandgap-referenced error amplifier driving an NPN output stage, enabling programmable shunt regulation via external resistor dividers. Its sharp turn-on and low temperature coefficient (±11mV over –40°C to +125°C) ensure stable closed-loop performance in SMPS feedback paths.
It operates with sink current from 100μA to 100mA and features low dynamic impedance (0.1Ω typ.) and high stability under capacitive loading - critical for maintaining phase margin in isolated flyback and forward converter topologies where secondary-side regulation is required.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495V ±0.5% at +25°C - sets base accuracy for programmable output voltage calculation VOUT = VREF × (1 + R1/R2) |
| Min Cathode Current | 50μA typical - enables regulation in ultra-low-power standby modes without auxiliary bias winding |
| Dynamic Impedance | 0.1Ω typical - minimizes output voltage ripple under transient load steps in feedback networks |
| Cathode Voltage Range | 2.495V to 36V - supports wide-output-range adapters (e.g., 5V–24V USB PD) without external series pass devices |
| Temp Stability | ±11mV over –40°C to +125°C - ensures <0.5% output drift in automotive cabin or industrial ambient environments |
| Sink Current Range | 100μA to 100mA - accommodates both light-load efficiency optimization and full-load regulation in 1A+ converters |
| Package | SOT89 (R code) - thermally robust 750mW power dissipation rating with exposed tab for PCB heat sinking |
Pinout & Package
SOT89 package with exposed thermal pad (Option 1 layout per DS39195 Rev. 3-2, p.14); 3-pin configuration optimized for high-current shunt regulation and thermal reliability in compact power designs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (REF) | Reference Input | High-impedance node connected to resistor divider midpoint; draws only 0.2–0.5μA - negligible loading on feedback network |
| Pin 2 (ANODE) | Anode Terminal | Connected to system ground or return path; forms current sink path with cathode - defines shunt current direction |
| Pin 3 (CATHODE) | Cathode Terminal | Connected to primary-side optocoupler LED or error amplifier input; sinks regulated current to maintain VREF at divider node |
Key Features
| Feature | Design Value |
|---|---|
| Low min cathode current | 50μA typical - reduces standby power loss by >30% vs. standard TL431 (100μA min) in no-load conditions |
| Programmable output range | 2.495V to 36V - eliminates need for multiple Zener values in multi-output adapter designs |
| Capacitive load stability | Stable with ≥100μF output capacitance - avoids oscillation in high-ESR electrolytic or bulk ceramic capacitor configurations |
| Thermal stability | ±11mV ΔVREF over –40°C to +125°C - maintains <0.44% output error without calibration in extended-temperature applications |
| Green compliance | RoHS 3 / Halogen-free / Antimony-free - meets IPC-1752A reporting requirements for automotive and medical OEMs |
Applications
| USB-C Power Delivery Adapter | Industrial 24V Switching Supply |
|---|---|
Use Scenario: Regulates 9V/15V/20V outputs in single-stage flyback with optocoupler feedback. IC Role / Device Role / Timing Role: Secondary-side shunt regulator providing precise voltage reference to optocoupler LED driver. Use Value: 0.5% VREF tolerance enables ±1% output accuracy across line/load/temperature - meeting USB PD 3.1 specification. |
Use Scenario: Feedback element in 24V/5A open-frame power supply for PLC I/O modules. IC Role / Device Role / Timing Role: Adjustable shunt reference stabilizing TL431-based error amplifier in isolated DC-DC stage. Use Value: Low 50μA min cathode current allows direct bias from auxiliary winding - eliminating startup resistor and reducing no-load consumption by 120mW. |
| Graphics Card VRM Monitor | Automotive Infotainment DC-DC |
Use Scenario: Precision voltage monitor for GPU core rail (0.8–1.2V) using external resistor scaling. IC Role / Device Role / Timing Role: High-stability reference source feeding comparator input for overvoltage protection circuitry. Use Value: ±11mV VREF drift over –40°C to +125°C ensures OVP threshold remains within ±0.9% - preventing false shutdowns during thermal cycling. |
Use Scenario: Feedback reference in 5V/3A buck converter powering head unit MCU and display interface. IC Role / Device Role / Timing Role: Shunt regulator in secondary-side feedback loop with automotive-grade optocoupler (e.g., PC817X). Use Value: SOT89 package with 750mW rating sustains 100mA sink current at +105°C ambient - enabling convection-cooled design without heatsink. |
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 | 100μA min cathode current; 2.495V ±1% VREF; higher 0.2Ω dynamic impedance | Lacks low-IKA capability for ultra-low-power standby; requires larger bias resistor in adapter no-load mode | Select when cost sensitivity outweighs standby power targets and ±1% VREF is acceptable |
| AS431ASTZTR-G1 | Same 50μA min cathode current; identical 2.495V ±0.5% VREF; SOT23-3 package (lower thermal mass) | SOT23 limits max continuous sink current to 70mA due to 350mW PD rating - unsuitable for >1A output supplies | Select for space-constrained, low-current applications (<500mA) where board area is prioritized over thermal headroom |
Compared with TL431ACDR, AP431SARTR-G1 reduces no-load power by 40% in USB-C adapters; compared with AS431ASTZTR-G1, it delivers 43% higher thermal margin (750mW vs. 350mW) in high-current SOT89 footprint - making it optimal for 1A+ industrial and automotive supplies.
Availability
AP431SARTR-G1 is available at Aetrix Electronics and suitable for USB-C power adapters, industrial 24V switching supplies, and automotive infotainment DC-DC converters requiring stable component supply with guaranteed long-term manufacturability.
Supply support for AP431SARTR-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 power management, signal integrity, and protection solutions for industrial, computing, and automotive markets.
The AP431S/AP431SH product line delivers precision shunt regulation with enhanced low-current performance, targeting next-generation energy-efficient AC-DC adapters and high-reliability industrial power systems.
FAQ
What is the maximum cathode voltage the AP431SARTR-G1 can regulate?
The AP431SARTR-G1 supports cathode voltages up to 36V under recommended operating conditions, with absolute maximum rating of 40V. This enables direct use in 24V industrial rails and 36V PoE++ powered devices without external voltage clamping.
Does AP431SARTR-G1 require an external capacitor for stability?
No external capacitor is required for basic regulation stability. The device is specified to remain stable with capacitive loads up to 100μF, making it compatible with common bulk electrolytic and ceramic output capacitors in switching supplies without added compensation components.
How does the 0.5% reference voltage tolerance impact output accuracy in a typical feedback design?
In a standard resistor-divider feedback network (VOUT = VREF × (1 + R1/R2)), the 0.5% VREF tolerance contributes directly to overall output error. Combined with resistor tolerances (e.g., 1% R1/R2), total system accuracy remains within ±1.5% - sufficient for most USB PD and industrial 24V applications without trimming.
Can AP431SARTR-G1 replace TL431 in existing designs without layout changes?
Yes - AP431SARTR-G1 uses the same SOT89 pinout (REF-ANODE-CATHODE) and electrical interface as TL431 variants in SOT89. No PCB modification is needed; however, reduced minimum cathode current may allow removal of startup resistors or downsizing of bias networks to improve efficiency.
AP431SARTR-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:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 100 µA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-89-3
AP431SARTR-G1 FAQ
1.How can I place an order for AP431SARTR-G1 through Aetrix?
Please submit a Request for Quotation (RFQ) for AP431SARTR-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 AP431SARTR-G1 reliable?
The price and inventory of AP431SARTR-G1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP431SARTR-G1 is usually 5 days.
3.What payment methods are accepted for AP431SARTR-G1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP431SARTR-G1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AP431SARTR-G1?
AP431SARTR-G1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AP431SARTR-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 AP431SARTR-G1?
For technical support, including AP431SARTR-G1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP431SARTR-G1 requirements.
6.How does Aetrix verify that AP431SARTR-G1 is sourced from the original manufacturer or authorized distributors?
All AP431SARTR-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 AP431SARTR-G1 meets industry standards.
7.What is the process for return or replacement of AP431SARTR-G1?
All AP431SARTR-G1 units undergo pre-shipment inspection (PSI). If there is an issue with AP431SARTR-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 AP431SARTR-G1 part is unused and in its original packaging.
Return procedure for AP431SARTR-G1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AP431SARTR-G1 Tags
-
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
-
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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