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Diodes Incorporated AS431IBZTR-G1
- Part No.:
- AS431IBZTR-G1
- Manufacturer:
- Diodes Incorporated
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
AS431IBZTR-G1.pdf
- Description:
- IC VREF SHUNT ADJ 1% TO92
- Quantity:
- Payment:
- Shipping:
Inventory:1,095
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Product details
Overview
AS431IBZTR-G1 from Diodes Incorporated is a three-terminal adjustable precision shunt regulator with 1.0% initial reference voltage tolerance (2.5 V), low minimum cathode current (50 µA max), 0.15 Ω dynamic impedance, and operation from –40°C to +125°C. It replaces Zener diodes in feedback loops of switching power supplies, battery chargers, and precision voltage references where thermal stability and capacitive-load immunity are critical.
For engineers reviewing the AS431IBZTR-G1 datasheet, AS431IBZTR-G1 pinout, AS431IBZTR-G1 application, or AS431IBZTR-G1 equivalent, key selection criteria include cathode current regulation threshold, reference voltage drift over temperature (±4.5 mV typical), output impedance under load, and SOT-23 package compatibility with high-density PCB layouts.
Technical Context
The AS431IBZTR-G1 implements a bandgap-referenced error amplifier driving an NPN pass transistor, enabling precise 2.5 V reference generation independent of cathode voltage up to 36 V. Its sharp turn-on characteristic and low ∆VREF/∆VKA (–0.5 to –2.0 mV/V) ensure stable regulation across wide input variations.
Designed for closed-loop feedback in DC-DC converters, it sinks 50 µA–100 mA cathode current while maintaining <0.5 Ω dynamic impedance at 1–100 mA and delivering <4.5 mV reference deviation from –40°C to +125°C - meeting requirements for industrial-grade power management systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage (VREF) | 2.500 V ±1.0% at +25°C - sets output voltage via external resistor divider (VOUT = VREF × (1 + R1/R2)) |
| Min Cathode Current (IKA min) | 50 µA max - enables regulation at ultra-low bias currents, supporting standby-mode power supply designs |
| Dynamic Impedance (ZKA) | 0.15 Ω typical at 1–100 mA - ensures minimal output voltage perturbation during load transients |
| Temp Coefficient (∆VREF) | ±4.5 mV typical over –40°C to +125°C - guarantees <0.18% reference drift, critical for precision feedback |
| Operating Temp Range | –40°C to +125°C - qualified for under-hood automotive, industrial motor drives, and telecom power systems |
| Cathode Voltage Range | 2.5 V to 36 V - supports wide-input buck, flyback, and forward converter topologies without external clamping |
| Package | SOT-23 - surface-mount, 3-pin footprint (REF/ANODE/CATHODE), compatible with automated assembly and thermal relief pads |
Pinout & Package
SOT-23 package: 3-pin, small-outline transistor outline with gull-wing leads; JEDEC MO-178 compliant; thermal resistance θJC = 113°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (REF) | Reference Input | High-impedance node sensing internal 2.5 V bandgap; connects to resistor divider midpoint in feedback loop |
| Pin 2 (ANODE) | Anode Terminal | Connected to system ground or return path; completes shunt current path through external resistors |
| Pin 3 (CATHODE) | Cathode Output | Sinks regulated current into primary-side controller IC (e.g., PWM IC COMP pin); sets feedback voltage level |
Key Features
| Feature | Design Value |
|---|---|
| Programmable Output Voltage | 2.5 V to 36 V via two-resistor divider - eliminates need for multiple fixed-voltage Zeners in BOM |
| Low Minimum Cathode Current | 50 µA max - enables stable regulation in low-power standby and light-load conditions without auxiliary bias winding |
| Capacitive Load Stability | Stable with ≥0.01 µF to 100 µF output capacitance - prevents oscillation in noisy switcher environments without added compensation |
| Lead-Free & Green Compliance | RoHS 3 (2015/863/EU), halogen-free (<900 ppm Br/Cl, <1000 ppm Sb) - meets IPC-1752A material declaration requirements |
| Wide Temperature Operation | –40°C to +125°C junction range - supports industrial and extended-temperature applications without derating |
Applications
| Switching Power Supply Feedback | Battery Charger Regulation |
|---|---|
|
Use Scenario: Primary-side feedback in isolated flyback converters for AC-DC adapters and USB PD power bricks. IC Role / Device Role / Timing Role: Shunt regulator providing precise 2.5 V reference to optocoupler LED, closing secondary-to-primary control loop. Use Value: Enables ±1% output voltage accuracy across line/load/temperature with no secondary-side controller. |
Use Scenario: Constant-voltage stage in multi-stage Li-ion charger ICs for portable electronics. IC Role / Device Role / Timing Role: Reference element setting charge termination voltage (e.g., 4.2 V ±0.05 V) via resistor network. Use Value: Maintains <±0.2% voltage tolerance over full temperature range, preventing overcharge and extending battery cycle life. |
| Voltage Adapter Reference | Graphic Card VRM Monitoring |
|
Use Scenario: Adjustable 3.3 V/5 V/12 V point-of-load regulators in industrial DIN-rail power modules. IC Role / Device Role / Timing Role: Precision shunt element in series-pass or LDO feedback path for programmable output rails. Use Value: Delivers <0.5% output tolerance with 0.15 Ω dynamic impedance, minimizing dropout under transient load steps. |
Use Scenario: GPU core voltage (VDDC) monitoring and fine-tuning circuitry on high-end graphics cards. IC Role / Device Role / Timing Role: Reference source for DAC-controlled voltage setpoint in digital VRM controllers (e.g., IR352xx). Use Value: Provides stable 2.5 V reference with <4.5 mV temp drift, enabling <±5 mV VDDC accuracy across ambient extremes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BIDBZR | 2.5 V ±0.5% tolerance, higher IKA(min) (100 µA), SOT-23-3, same pinout | Better initial accuracy but higher minimum cathode current limits use in ultra-low-power standby | Select when tighter reference tolerance is required and system can support ≥100 µA bias current |
| AP431SAG-13 | Same 1.0% tolerance, lower ZKA (0.10 Ω typ), improved noise performance, SOT-23 | Superior dynamic regulation for high-frequency sync-buck controllers; not recommended for new designs per Diodes' note | Prefer for noise-sensitive applications if legacy design allows; verify lifecycle status before long-term sourcing |
Compared with TL431BIDBZR and AP431SAG-13, AS431IBZTR-G1 offers optimal balance of low minimum cathode current (50 µA max), industrial temperature range, and RoHS 3/Green compliance - making it ideal for cost-sensitive, thermally demanding power adapter and charger designs requiring reliable long-term availability.
Availability
AS431IBZTR-G1 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 RoHS 3-compliant sourcing.
Supply support for AS431IBZTR-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 consumer markets.
The AS431I series belongs to Diodes' precision shunt regulator product line, engineered specifically for high-stability, low-current feedback in isolated and non-isolated DC-DC converters where Zener replacement with superior thermal and dynamic performance is required.
FAQ
What is the maximum cathode voltage rating for AS431IBZTR-G1?
The absolute maximum cathode-to-anode voltage (VKA) is 40 V, with recommended operating range up to 36 V. Exceeding 36 V risks violating the specified ∆VREF/∆VKA specification and may increase reference voltage drift beyond datasheet limits.
Can AS431IBZTR-G1 drive a 100 µF output capacitor without oscillation?
Yes - the device is characterized for stable operation with load capacitance from 0.01 µF to 100 µF across cathode currents of 1–100 mA. No external compensation is needed, as confirmed by stability boundary plots in DS36816 Rev. 4–3, page 8.
How does the 1.0% reference voltage tolerance affect output accuracy in a 12 V power supply?
In a 12 V design using R1/R2 = 3.8, the 1.0% VREF tolerance contributes ±0.12 V (±1%) to total output error. Combined with resistor tolerance and temperature drift, total accuracy remains within ±2% - sufficient for most Class II AC-DC adapters per IEC 61347.
Is AS431IBZTR-G1 pin-compatible with TL431 in SOT-23 packages?
Yes - both use identical SOT-23 pinout (Pin 1 = REF, Pin 2 = ANODE, Pin 3 = CATHODE) and share functional equivalence. However, AS431IBZTR-G1 draws only 50 µA minimum cathode current versus TL431's 100 µA, enabling direct drop-in replacement in low-bias designs.
AS431IBZTR-G1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Series:
- -
- Packaging:
- Tape & Box (TB)
- 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:
- ±1%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 50 µA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92
AS431IBZTR-G1 FAQ
1.How can I place an order for AS431IBZTR-G1 through Aetrix?
Please submit a Request for Quotation (RFQ) for AS431IBZTR-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 AS431IBZTR-G1 reliable?
The price and inventory of AS431IBZTR-G1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AS431IBZTR-G1 is usually 5 days.
3.What payment methods are accepted for AS431IBZTR-G1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AS431IBZTR-G1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AS431IBZTR-G1?
AS431IBZTR-G1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AS431IBZTR-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 AS431IBZTR-G1?
For technical support, including AS431IBZTR-G1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AS431IBZTR-G1 requirements.
6.How does Aetrix verify that AS431IBZTR-G1 is sourced from the original manufacturer or authorized distributors?
All AS431IBZTR-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 AS431IBZTR-G1 meets industry standards.
7.What is the process for return or replacement of AS431IBZTR-G1?
All AS431IBZTR-G1 units undergo pre-shipment inspection (PSI). If there is an issue with AS431IBZTR-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 AS431IBZTR-G1 part is unused and in its original packaging.
Return procedure for AS431IBZTR-G1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AS431IBZTR-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
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LM4040EIM3-2.5/NOPB
Texas Instruments
-
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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