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Diodes Incorporated AP431SRG-7
- Part No.:
- AP431SRG-7
- Manufacturer:
- Diodes Incorporated
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
AP431SRG-7.pdf
- Description:
- IC VREF SHUNT ADJ 1% SOT23R
- Quantity:
- Payment:
- Shipping:
Inventory:1,231
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Product details
Overview
AP431SRG-7 from Diodes Incorporated is a 3-terminal adjustable precision shunt regulator with 2.495V ±1% reference voltage, 0.2Ω dynamic output impedance, and 200mA sink current capability. It operates from -20°C to +85°C and sets programmable output voltages from 2.495V to 36V using two external resistors-commonly deployed in feedback loops of isolated DC-DC converters and voltage monitor circuits.
For engineers reviewing the AP431SRG-7 datasheet, AP431SRG-7 pinout, AP431SRG-7 application, or AP431SRG-7 equivalent, key selection criteria include reference voltage tolerance, cathode current regulation threshold (300μA), temperature coefficient (30ppm/°C), and SOT23R package thermal performance for space-constrained power supply designs.
Technical Context
The AP431SRG-7 implements an internal bandgap reference and high-gain error amplifier driving an NPN output stage, enabling sharp turn-on and stable regulation across load and line variations. Its active sink architecture replaces Zener diodes in precision feedback paths where low dynamic impedance and tight initial tolerance are required.
It functions as a 2.495V reference with programmable gain via external resistor dividers, delivering <1.2μA reference input current deviation over temperature and maintaining regulation down to 300μA cathode current-critical for low-power standby modes in AC-DC adapters and LED drivers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495V ±1% - ensures initial output accuracy without trimming in 5V/12V/24V SMPS feedback networks |
| Sink Current Capability | 200mA - supports direct drive of optocoupler LEDs in isolated flyback controllers |
| Dynamic Output Impedance | 0.2Ω - minimizes output voltage variation under fast load transients in regulated auxiliary supplies |
| Min Cathode Current | 300μA - enables stable regulation during light-load or burst-mode operation |
| Temp Coefficient | 30ppm/°C - maintains ≤±8mV drift over -20°C to +85°C ambient, suitable for industrial-grade power supplies |
| Operating Temp Range | -20°C to +85°C - validated for use in commercial and extended-temperature embedded power rails |
| Package | SOT23R - RoHS-compliant, halogen-free surface-mount package with 0.55mm pitch and 1.3mm height for compact PCB layouts |
Pinout & Package
SOT23R package: 3-pin, lead-free, halogen-free, 1.3mm height, 2.4mm × 1.3mm footprint. Thermal resistance θJA = 250°C/W (JEDEC standard board).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Pin 1) | Current Sink Node | Connects to primary-side feedback node; carries full regulated sink current up to 200mA |
| Anode (Pin 2) | Return Path | Connected to system ground or secondary-side common; completes regulation loop |
| REF (Pin 3) | Reference Input | High-impedance sense node tied to resistor divider midpoint; draws only 1.4–3.5μA |
Key Features
| Feature | Design Value |
|---|---|
| Precision Reference Voltage | 2.495V ±1% - eliminates need for trim-pot in most 5V/12V/15V output designs, reducing BOM cost and long-term drift |
| Low Dynamic Output Impedance | 0.2Ω - suppresses ripple coupling into feedback path, improving PSRR in multi-output converters |
| Fast Turn-On Response | Sub-microsecond rise time - prevents overshoot during power-up or load-step recovery in regulated bias supplies |
| Programmable Output Voltage | 2.495V to 36V - enables single-part support across wide range of isolated and non-isolated topologies |
| Low Reference Input Current | 1.4–3.5μA - reduces divider resistor power loss and thermal drift in high-impedance feedback networks |
Applications
| AC-DC Adapter Feedback | Voltage Monitor Circuit |
|---|---|
Use Scenario: Regulates 5V/12V outputs in offline flyback converters using optocoupler-coupled feedback. IC Role / Device Role / Timing Role: Shunt regulator providing precise reference voltage to optocoupler LED anode; controls primary-side PWM duty cycle via secondary-side error signal. Use Value: Enables ±1% output regulation without trimming, meeting Energy Star Level VI efficiency requirements at light load. |
Use Scenario: Detects over-voltage and under-voltage conditions on 3.3V/5V microcontroller supply rails. IC Role / Device Role / Timing Role: Precision comparator reference node; drives logic-level output via external transistor when VIN exceeds preset thresholds. Use Value: Achieves ±20mV detection window using fixed-resistor dividers, eliminating need for dedicated supervisor ICs. |
| LED Constant-Current Driver | Isolated Bias Supply Regulation |
Use Scenario: Sets stable current for high-brightness LED strings in signage and automotive lighting. IC Role / Device Role / Timing Role: Shunt-based current sink; REF pin senses voltage across sense resistor, adjusting cathode current to maintain IOUT = VREF/RSENSE. Use Value: Delivers ±2% current accuracy over temperature, supporting Class A thermal derating without recalibration. |
Use Scenario: Regulates auxiliary 15V bias supply for gate drivers in half-bridge motor control inverters. IC Role / Device Role / Timing Role: Secondary-side shunt regulator stabilizing isolated auxiliary winding output; improves startup reliability and cross-regulation. Use Value: Maintains regulation down to 300μA cathode current, enabling clean shutdown during fault conditions without latch-up. |
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 | 2.495V ±0.5%, SO-8 package, higher 100mA max cathode current, 0.22Ω impedance | Requires larger PCB area; better suited for high-current bias rails where thermal margin >1W is available | Select when tighter initial tolerance (±0.5%) and SO-8 thermal mass are prioritized over size constraints |
| AS431ARTDT-13 | 2.5V ±1%, SOT23-3 package, 100mA sink, 0.3Ω impedance, not recommended for new design per Diodes Inc. | Limited availability and lifecycle support; lacks AP431's 200mA rating and 30ppm/°C tempco | Avoid for new designs; only consider for legacy repair or drop-in replacement where AP431SRG-7 is unavailable |
Compared with TL431ACDBVR and AS431ARTDT-13, AP431SRG-7 offers superior sink current (200mA vs. 100mA), lower thermal resistance in SOT23R, and tighter temperature stability (30ppm/°C), making it optimal for compact, high-reliability AC-DC and LED driver feedback loops.
Availability
AP431SRG-7 is available at Aetrix Electronics and suitable for AC-DC adapter feedback, LED constant-current drivers, and isolated bias supply regulation requiring stable component supply, consistent parametric performance, and RoHS-compliant packaging.
Supply support for AP431SRG-7 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 consumer markets.
The AP431 series belongs to Diodes' precision shunt regulator product line, designed specifically to replace Zener diodes in high-accuracy, low-drift feedback applications across switching power supplies and voltage monitoring systems.
FAQ
What is the minimum cathode current required for regulation in AP431SRG-7?
The AP431SRG-7 requires a minimum cathode current of 300μA to maintain regulation, verified across -20°C to +85°C. This low threshold enables stable operation in burst-mode or light-load conditions typical in energy-efficient AC-DC adapters and standby power supplies.
Can AP431SRG-7 be used in place of a Zener diode in feedback circuits?
Yes-AP431SRG-7 is explicitly designed as a Zener diode replacement, offering sharper turn-on, lower dynamic impedance (0.2Ω vs. typical Zener's 5–20Ω), and ±1% reference tolerance without trimming. Its active circuitry provides superior line and load regulation in SMPS feedback paths.
What is the maximum output voltage achievable with AP431SRG-7?
The AP431SRG-7 supports programmable output voltages up to 36V by selecting appropriate R1/R2 resistor values in the external divider network. The upper limit is constrained by the absolute maximum cathode voltage rating of +36V, not by internal circuitry.
Is AP431SRG-7 suitable for automotive applications?
No-AP431SRG-7 is specified for commercial/extended temperature range (-20°C to +85°C) and is not AEC-Q200 qualified. For automotive use, Diodes Incorporated recommends the AEC-Q200 qualified AP431QG-13 (SO-8) or AS431 variants with extended temperature screening.
AP431SRG-7 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:
- Obsolete
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 2.495V
- Voltage - Output (Max):
- 36 V
- Current - Output:
- 200 mA
- Tolerance:
- ±1%
- Temperature Coefficient:
- 30ppm/°C
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 500 µA
- Operating Temperature:
- -20°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT23R
AP431SRG-7 FAQ
1.How can I place an order for AP431SRG-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for AP431SRG-7 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 AP431SRG-7 reliable?
The price and inventory of AP431SRG-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP431SRG-7 is usually 5 days.
3.What payment methods are accepted for AP431SRG-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP431SRG-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AP431SRG-7?
AP431SRG-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AP431SRG-7 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 AP431SRG-7?
For technical support, including AP431SRG-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP431SRG-7 requirements.
6.How does Aetrix verify that AP431SRG-7 is sourced from the original manufacturer or authorized distributors?
All AP431SRG-7 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 AP431SRG-7 meets industry standards.
7.What is the process for return or replacement of AP431SRG-7?
All AP431SRG-7 units undergo pre-shipment inspection (PSI). If there is an issue with AP431SRG-7, 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 AP431SRG-7 part is unused and in its original packaging.
Return procedure for AP431SRG-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AP431SRG-7 Tags
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TL431BQDBZR
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AN431AN-ATRG1
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AZ431LBNTR-G1
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LM4040DIM3X-2.5/NOPB
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AZ431LANTR-G1
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