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Diodes Incorporated AP431SANTR-G1
- Part No.:
- AP431SANTR-G1
- Manufacturer:
- Diodes Incorporated
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
AP431SANTR-G1.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:25,991
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Product details
Overview
AP431SANTR-G1 from Diodes Incorporated is a 3-terminal adjustable precision shunt regulator with 0.5% initial reference voltage tolerance (2.500 V at +25°C), 50 µA typical minimum cathode current for regulation, 0.1 Ω typical dynamic impedance, and operation from −40°C to +125°C. It replaces Zener diodes in feedback loops of switching power supplies, USB chargers, and voltage adapters where low-power, stable reference performance is required.
For engineers reviewing the AP431SANTR-G1 datasheet, AP431SANTR-G1 pinout, AP431SANTR-G1 application, or AP431SANTR-G1 equivalent, this device serves as a thermally stable, low-IK(min) shunt reference for closed-loop voltage regulation-particularly where <100 µA cathode bias current and <11 mV reference drift over −40°C to +125°C are critical selection criteria.
Technical Context
The AP431SANTR-G1 implements a bandgap-referenced error amplifier driving an NPN output stage in a 3-terminal shunt topology. Its sharp turn-on and low temperature coefficient (±11 mV max over full temperature range) stem from matched transistor pairs and curvature-compensated reference design.
It operates as a two-quadrant sink: regulating when cathode voltage exceeds VREF × (1 + R1/R2), with sink current controllable from 100 µA to 100 mA. Stability under capacitive loads up to 100 µF is ensured by internal compensation optimized for common feedback configurations.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VREF | 2.500 V ±0.5% at +25°C - sets precise output voltage via external resistor divider (VOUT = VREF × (1 + R1/R2)) |
| IK(min) | 50 µA typical - enables regulation with ultra-low bias current, reducing standby power in battery-powered adapters |
| ZKA | 0.1 Ω typical - ensures minimal output voltage shift under load transients (ΔV = ILOAD × 0.1 Ω) |
| ΔVREF | 11 mV typical (−40°C to +125°C) - guarantees ≤0.44% reference drift across industrial temperature range |
| VKA(max) | 36 V - supports regulation in 24 V and 32 V input systems without external clamping |
| IKA | 100 mA max continuous - delivers sufficient sink current for optocoupler-driven flyback controllers |
| Package | SOT23-3 (Package Code N) - surface-mount footprint compatible with high-density PCB layouts and automated assembly |
Pinout & Package
SOT23-3 package (JEDEC TO-236AB), 3-pin surface-mount, 1.3 mm height, RoHS-compliant matte tin plating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (REF) | Reference input | High-impedance node sensing voltage divider midpoint; draws only 0.2–0.5 µA for feedback stability |
| 2 (ANODE) | Anode connection | Connected to system ground or return path; completes shunt current loop through external resistor |
| 3 (CATHODE) | Cathode output | Sinks regulated current into feedback network; voltage at this pin defines regulated output via divider ratio |
Key Features
| Feature | Design Value |
|---|---|
| Low minimum cathode current | 50 µA typ. enables regulation in energy-harvesting and ultra-low-power adapter designs |
| Programmable output range | 2.5 V to 36 V via two-resistor divider - eliminates need for multiple fixed-voltage references |
| Capacitive load stability | Stable with ≥100 µF output capacitance - simplifies EMI filtering without phase compensation networks |
| Thermal drift control | 11 mV max ΔVREF over −40°C to +125°C - maintains tight output tolerance in automotive under-hood environments |
| Dynamic impedance | 0.1 Ω typ. - minimizes output voltage perturbation during fast load steps in DC-DC converters |
Applications
| USB-C Power Delivery Adapters | Industrial 24V Switch-Mode Power Supplies |
|---|---|
|
Use Scenario: Regulating 9 V / 15 V / 20 V PPS output in compact USB-C PD adapters with <500 mW standby consumption. IC Role / Device Role / Timing Role: Precision shunt reference in optocoupler feedback loop, setting secondary-side output voltage with ±1% accuracy. Use Value: 50 µA IK(min) reduces no-load current by >3× versus standard TL431, enabling Energy Star Level VI compliance. |
Use Scenario: Voltage sensing and regulation in isolated 24 V/5 A industrial SMPS for PLC I/O modules. IC Role / Device Role / Timing Role: Primary-side referenced shunt regulator controlling PWM duty cycle via optocoupler current transfer ratio. Use Value: 0.1 Ω dynamic impedance ensures <10 mV output deviation during 1 A load steps, improving transient response. |
| Automotive LED Headlamp Drivers | Point-of-Load Voltage References |
|
Use Scenario: Setting constant-current reference for buck-boost LED drivers in headlamp ECU modules operating at −40°C to +125°C. IC Role / Device Role / Timing Role: Shunt-based current-sense reference feeding into op-amp comparator controlling MOSFET gate drive. Use Value: 11 mV max VREF drift over full temperature range maintains LED current accuracy within ±2% across ambient extremes. |
Use Scenario: Providing stable 2.5 V reference for ADCs and DACs in medical sensor signal chains. IC Role / Device Role / Timing Role: Low-noise, low-drift voltage reference source decoupled from noisy digital supply rails. Use Value: 0.5% initial tolerance and <0.1 Ω output impedance minimize code-to-code errors in 12-bit+ data converters. |
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 | 1% VREF tolerance (2.495 V), 100 µA IK(min), 0.2 Ω ZKA | Higher minimum cathode current increases standby loss in low-power adapters | Select when cost sensitivity outweighs ultra-low IK(min) requirement and 1% tolerance is acceptable |
| AS431ASTZTR-G1 | Same 0.5% VREF tolerance, but 60 µA IK(min), 0.15 Ω ZKA, SOT23-3 pinout identical | Marginally higher dynamic impedance affects transient response in high-bandwidth regulators | Choose if dual-sourcing from Diodes and ASI is required; verify layout compatibility with thermal pad variant |
Compared with TL431ACDBVR and AS431ASTZTR-G1, the AP431SANTR-G1 delivers the lowest confirmed IK(min) (50 µA) and tightest ZKA (0.1 Ω), making it optimal for energy-constrained, high-accuracy feedback paths where every microamp and milliohm matters.
Availability
AP431SANTR-G1 is available at Aetrix Electronics and suitable for USB-C power adapters, industrial 24 V switch-mode power supplies, and automotive LED driver designs requiring stable component supply with guaranteed long-term continuity.
Supply support for AP431SANTR-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 AP431S/AP431SH product line was designed specifically for precision voltage regulation in space-constrained, low-power feedback circuits-emphasizing thermal stability, low quiescent current, and robust capacitive-load immunity.
FAQ
What is the maximum cathode voltage the AP431SANTR-G1 can regulate?
The AP431SANTR-G1 supports cathode voltages up to 36 V under recommended operating conditions. Absolute maximum cathode voltage is 40 V, but sustained operation above 36 V risks exceeding thermal limits and degrading long-term reliability. For 48 V systems, external clamping or series resistors are required.
Can the AP431SANTR-G1 replace a TL431 in existing designs without layout changes?
Yes-the AP431SANTR-G1 uses the same SOT23-3 pinout (REF-ANODE-CATHODE) and electrical interface as TL431 variants. However, its lower 50 µA IK(min) may require adjusting the upper feedback resistor to maintain sufficient bias current, especially in high-impedance divider networks.
Does the AP431SANTR-G1 require an external capacitor for stability?
No external capacitor is required for basic regulation stability. The device is internally compensated and remains stable with capacitive loads up to 100 µF. However, a 1 nF ceramic capacitor between REF and ANODE is recommended in noisy environments to suppress high-frequency coupling into the reference node.
Is the AP431SANTR-G1 qualified for automotive applications?
The AP431SANTR-G1 is not AEC-Q100 qualified. While it operates across −40°C to +125°C and meets industrial reliability standards, Diodes offers separate AEC-Q100-qualified versions (e.g., AP431SAQTR-G1) with PPAP documentation and IATF 16949 manufacturing controls for automotive use.
AP431SANTR-G1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- 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-23-3
AP431SANTR-G1 FAQ
1.How can I place an order for AP431SANTR-G1 through Aetrix?
Please submit a Request for Quotation (RFQ) for AP431SANTR-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 AP431SANTR-G1 reliable?
The price and inventory of AP431SANTR-G1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP431SANTR-G1 is usually 5 days.
3.What payment methods are accepted for AP431SANTR-G1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP431SANTR-G1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AP431SANTR-G1?
AP431SANTR-G1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AP431SANTR-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 AP431SANTR-G1?
For technical support, including AP431SANTR-G1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP431SANTR-G1 requirements.
6.How does Aetrix verify that AP431SANTR-G1 is sourced from the original manufacturer or authorized distributors?
All AP431SANTR-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 AP431SANTR-G1 meets industry standards.
7.What is the process for return or replacement of AP431SANTR-G1?
All AP431SANTR-G1 units undergo pre-shipment inspection (PSI). If there is an issue with AP431SANTR-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 AP431SANTR-G1 part is unused and in its original packaging.
Return procedure for AP431SANTR-G1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AP431SANTR-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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